🎨 #44

pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
     Description: Solo POM.
-    Version: 3.18.3.80, Jan 14, 2020
+    Version: 3.18.3.81, Jan 16, 2020
     Author: <a href="http://88250.b3log.org">Liang Ding</a>
     Author: <a href="http://www.annpeter.cn">Ann Peter</a>
     Author: <a href="http://vanessa.b3log.org">Vanessa</a>
@@ -73,9 +73,8 @@
     </scm>
 
     <properties>
-        <org.b3log.latke.version>3.1.1</org.b3log.latke.version>
+        <org.b3log.latke.version>3.1.3</org.b3log.latke.version>
 
-        <slf4j.version>1.7.28</slf4j.version>
         <jsoup.version>1.12.1</jsoup.version>
         <flexmark.version>0.50.40</flexmark.version>
         <commons-cli.version>1.3.1</commons-cli.version>
@@ -91,7 +90,6 @@
         <coveralls-maven-plugin.version>4.3.0</coveralls-maven-plugin.version>
         <jacoco-maven-plugin.version>0.8.2</jacoco-maven-plugin.version>
         <testng.version>6.1.1</testng.version>
-        <mysql-connector-java.version>8.0.18</mysql-connector-java.version>
 
         <maven.compiler.target>1.8</maven.compiler.target>
         <maven.compiler.source>1.8</maven.compiler.source>
@@ -111,12 +109,6 @@
             </exclusions>
         </dependency>
 
-        <dependency>
-            <groupId>mysql</groupId>
-            <artifactId>mysql-connector-java</artifactId>
-            <version>${mysql-connector-java.version}</version>
-        </dependency>
-
         <dependency>
             <groupId>org.b3log</groupId>
             <artifactId>latke-repository-mysql</artifactId>
@@ -142,12 +134,6 @@
             <version>${jsoup.version}</version>
         </dependency>
 
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-log4j12</artifactId>
-            <version>${slf4j.version}</version>
-        </dependency>
-
         <dependency>
             <groupId>com.vladsch.flexmark</groupId>
             <artifactId>flexmark-all</artifactId>

src/main/java/org/b3log/solo/Server.java

@@ -19,13 +19,14 @@ package org.b3log.solo;
 
 import org.apache.commons.cli.*;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.EventManager;
 import org.b3log.latke.http.BaseServer;
 import org.b3log.latke.http.Dispatcher;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.plugin.PluginManager;
 import org.b3log.latke.plugin.ViewLoadEventHandler;
 import org.b3log.latke.repository.Transaction;
@@ -54,7 +55,7 @@ public final class Server extends BaseServer {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(Server.class);
+    private static final Logger LOGGER = LogManager.getLogger(Server.class);
 
     /**
      * Solo version.
@@ -271,7 +272,7 @@ public final class Server extends BaseServer {
         }));
 
         Stopwatchs.end();
-        LOGGER.log(Level.DEBUG, "Stopwatch: {0}{1}", Strings.LINE_SEPARATOR, Stopwatchs.getTimingStat());
+        LOGGER.log(Level.DEBUG, "Stopwatch: {}{}", Strings.LINE_SEPARATOR, Stopwatchs.getTimingStat());
         Stopwatchs.release();
 
         server.start(Integer.parseInt(portArg));
@@ -428,7 +429,6 @@ public final class Server extends BaseServer {
         Dispatcher.post("/console/plugin/updateSetting", pluginConsole::updateSetting);
 
 
-
         final PreferenceConsole preferenceConsole = beanManager.getReference(PreferenceConsole.class);
         Dispatcher.get("/console/signs/", preferenceConsole::getSigns);
         Dispatcher.get("/console/preference/", preferenceConsole::getPreference);

src/main/java/org/b3log/solo/event/B3ArticleSender.java

@@ -20,14 +20,15 @@ package org.b3log.solo.event;
 import jodd.http.HttpRequest;
 import jodd.http.HttpResponse;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.AbstractEventListener;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.ioc.BeanManager;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.User;
 import org.b3log.solo.Server;
 import org.b3log.solo.model.Article;
@@ -56,12 +57,12 @@ public class B3ArticleSender extends AbstractEventListener<JSONObject> {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(B3ArticleSender.class);
+    private static final Logger LOGGER = LogManager.getLogger(B3ArticleSender.class);
 
     @Override
     public void action(final Event<JSONObject> event) {
         final JSONObject data = event.getData();
-        LOGGER.log(Level.DEBUG, "Processing an event [type={0}, data={1}] in listener [className={2}]",
+        LOGGER.log(Level.DEBUG, "Processing an event [type={}, data={}] in listener [className={}]",
                 event.getType(), data, B3ArticleSender.class.getName());
 
         pushArticleToRhy(data);
@@ -77,19 +78,19 @@ public class B3ArticleSender extends AbstractEventListener<JSONObject> {
             final JSONObject originalArticle = data.getJSONObject(Article.ARTICLE);
             final String title = originalArticle.getString(Article.ARTICLE_TITLE);
             if (Article.ARTICLE_STATUS_C_PUBLISHED != originalArticle.optInt(Article.ARTICLE_STATUS)) {
-                LOGGER.log(Level.INFO, "Ignored push a draft [title={0}] to Rhy", title);
+                LOGGER.log(Level.INFO, "Ignored push a draft [title={}] to Rhy", title);
 
                 return;
             }
 
             if (StringUtils.isNotBlank(originalArticle.optString(Article.ARTICLE_VIEW_PWD))) {
-                LOGGER.log(Level.INFO, "Article [title={0}] is a password article, ignored push to Rhy", title);
+                LOGGER.log(Level.INFO, "Article [title={}] is a password article, ignored push to Rhy", title);
 
                 return;
             }
 
             if (!originalArticle.optBoolean(Common.POST_TO_COMMUNITY)) {
-                LOGGER.log(Level.INFO, "Article [title={0}] push flag [postToCommunity] is [false], ignored push to Rhy", title);
+                LOGGER.log(Level.INFO, "Article [title={}] push flag [postToCommunity] is [false], ignored push to Rhy", title);
 
                 return;
             }

src/main/java/org/b3log/solo/event/B3ArticleUpdater.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.event;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.event.AbstractEventListener;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.json.JSONObject;
 
 /**
@@ -40,11 +41,11 @@ public class B3ArticleUpdater extends AbstractEventListener<JSONObject> {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(B3ArticleUpdater.class);
+    private static final Logger LOGGER = LogManager.getLogger(B3ArticleUpdater.class);
 
     public void action(final Event<JSONObject> event) {
         final JSONObject data = event.getData();
-        LOGGER.log(Level.DEBUG, "Processing an event [type={0}, data={1}] in listener [className={2}]",
+        LOGGER.log(Level.DEBUG, "Processing an event [type={}, data={}] in listener [className={}]",
                 event.getType(), data, B3ArticleUpdater.class.getName());
 
         B3ArticleSender.pushArticleToRhy(data);

src/main/java/org/b3log/solo/event/B3CommentSender.java

@@ -18,14 +18,15 @@
 package org.b3log.solo.event;
 
 import jodd.http.HttpRequest;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.AbstractEventListener;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.ioc.Inject;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.User;
 import org.b3log.solo.Server;
 import org.b3log.solo.model.Article;
@@ -51,7 +52,7 @@ public class B3CommentSender extends AbstractEventListener<JSONObject> {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(B3CommentSender.class);
+    private static final Logger LOGGER = LogManager.getLogger(B3CommentSender.class);
 
     /**
      * Option query service.
@@ -75,7 +76,7 @@ public class B3CommentSender extends AbstractEventListener<JSONObject> {
     public void action(final Event<JSONObject> event) {
         final JSONObject data = event.getData();
 
-        LOGGER.log(Level.DEBUG, "Processing an event [type={0}, data={1}] in listener [className={2}]",
+        LOGGER.log(Level.DEBUG, "Processing an event [type={}, data={}] in listener [className={}]",
                 event.getType(), data, B3ArticleSender.class.getName());
         try {
             final JSONObject originalComment = data.getJSONObject(Comment.COMMENT);

src/main/java/org/b3log/solo/event/PluginRefresher.java

@@ -17,12 +17,13 @@
  */
 package org.b3log.solo.event;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.event.AbstractEventListener;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.ioc.BeanManager;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.plugin.AbstractPlugin;
 import org.b3log.latke.plugin.PluginManager;
 import org.b3log.latke.repository.Transaction;
@@ -44,13 +45,13 @@ public class PluginRefresher extends AbstractEventListener<List<AbstractPlugin>>
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PluginRefresher.class);
+    private static final Logger LOGGER = LogManager.getLogger(PluginRefresher.class);
 
     @Override
     public void action(final Event<List<AbstractPlugin>> event) {
         final List<AbstractPlugin> plugins = event.getData();
 
-        LOGGER.log(Level.DEBUG, "Processing an event [type={0}, data={1}] in listener [className={2}]",
+        LOGGER.log(Level.DEBUG, "Processing an event [type={}, data={}] in listener [className={}]",
                 event.getType(), plugins, PluginRefresher.class.getName());
 
         final BeanManager beanManager = BeanManager.getInstance();

src/main/java/org/b3log/solo/model/atom/Feed.java

@@ -19,9 +19,7 @@ package org.b3log.solo.model.atom;
 
 import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.util.XMLs;
-import org.b3log.solo.processor.FeedProcessor;
 
 import java.util.ArrayList;
 import java.util.Date;
@@ -47,11 +45,6 @@ public final class Feed {
      */
     public static final String TIME_ZONE_ID = "Asia/Shanghai";
 
-    /**
-     * Logger.
-     */
-    private static final Logger LOGGER = Logger.getLogger(FeedProcessor.class);
-
     /**
      * Link variable.
      */

src/main/java/org/b3log/solo/processor/AfterRequestHandler.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.processor;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.handler.Handler;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.jdbc.JdbcRepository;
 import org.b3log.latke.util.Stopwatchs;
 import org.b3log.latke.util.Strings;
@@ -34,14 +35,14 @@ import org.b3log.latke.util.Strings;
  */
 public class AfterRequestHandler implements Handler {
 
-    private static final Logger LOGGER = Logger.getLogger(AfterRequestHandler.class);
+    private static final Logger LOGGER = LogManager.getLogger(AfterRequestHandler.class);
 
     @Override
     public void handle(final RequestContext context) {
         JdbcRepository.dispose();
         Stopwatchs.end();
 
-        LOGGER.log(Level.TRACE, "Stopwatch: {0}{1}", Strings.LINE_SEPARATOR, Stopwatchs.getTimingStat());
+        LOGGER.log(Level.TRACE, "Stopwatch: {}{}", Strings.LINE_SEPARATOR, Stopwatchs.getTimingStat());
         Stopwatchs.release();
     }
 }

src/main/java/org/b3log/solo/processor/ArticleProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.Event;
@@ -30,8 +33,6 @@ import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.http.renderer.TextHtmlRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.User;
 import org.b3log.latke.service.LangPropsService;
@@ -64,7 +65,7 @@ public class ArticleProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleProcessor.class);
 
     /**
      * Article query service.
@@ -585,7 +586,7 @@ public class ArticleProcessor {
         try {
             final String authorId = context.pathVar("author");
             final int currentPageNum = Paginator.getPage(request);
-            LOGGER.log(Level.DEBUG, "Request author articles [authorId={0}, currentPageNum={1}]", authorId, currentPageNum);
+            LOGGER.log(Level.DEBUG, "Request author articles [authorId={}, currentPageNum={}]", authorId, currentPageNum);
 
             final JSONObject preference = optionQueryService.getPreference();
             if (null == preference) {
@@ -646,10 +647,10 @@ public class ArticleProcessor {
         try {
             final int currentPageNum = Paginator.getPage(request);
             final String archiveDateString = context.pathVar("yyyy") + "/" + context.pathVar("MM");
-            LOGGER.log(Level.DEBUG, "Request archive date [string={0}, currentPageNum={1}]", archiveDateString, currentPageNum);
+            LOGGER.log(Level.DEBUG, "Request archive date [string={}, currentPageNum={}]", archiveDateString, currentPageNum);
             final JSONObject result = archiveDateQueryService.getByArchiveDateString(archiveDateString);
             if (null == result) {
-                LOGGER.log(Level.DEBUG, "Can not find articles for the specified archive date[string={0}]", archiveDateString);
+                LOGGER.log(Level.DEBUG, "Can not find articles for the specified archive date[string={}]", archiveDateString);
                 context.sendError(404);
 
                 return;
@@ -704,12 +705,12 @@ public class ArticleProcessor {
         }
 
         final String articleId = article.optString(Keys.OBJECT_ID);
-        LOGGER.log(Level.DEBUG, "Article [id={0}]", articleId);
+        LOGGER.log(Level.DEBUG, "Article [id={}]", articleId);
 
         final AbstractFreeMarkerRenderer renderer = new SkinRenderer(context, "article.ftl");
 
         try {
-            LOGGER.log(Level.TRACE, "Article [title={0}]", article.getString(Article.ARTICLE_TITLE));
+            LOGGER.log(Level.TRACE, "Article [title={}]", article.getString(Article.ARTICLE_TITLE));
             articleQueryService.markdown(article);
 
             article.put(Article.ARTICLE_T_CREATE_DATE, new Date(article.optLong(Article.ARTICLE_CREATED)));

src/main/java/org/b3log/solo/processor/B3Receiver.java

@@ -18,14 +18,15 @@
 package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
 import org.b3log.latke.repository.Transaction;
@@ -56,7 +57,7 @@ public class B3Receiver {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(B3Receiver.class);
+    private static final Logger LOGGER = LogManager.getLogger(B3Receiver.class);
 
     /**
      * User repository.

src/main/java/org/b3log/solo/processor/BlogProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
@@ -27,8 +30,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.User;
 import org.b3log.solo.Server;
@@ -39,6 +40,7 @@ import org.json.JSONArray;
 import org.json.JSONObject;
 
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 
 /**
  * Blog processor.
@@ -53,7 +55,7 @@ public class BlogProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(BlogProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(BlogProcessor.class);
 
     /**
      * Article query service.
@@ -92,7 +94,7 @@ public class BlogProcessor {
 
     static {
         try (final InputStream tplStream = BlogProcessor.class.getResourceAsStream("/manifest.json.tpl")) {
-            PWA_MANIFESTO_JSON = IOUtils.toString(tplStream, "UTF-8");
+            PWA_MANIFESTO_JSON = IOUtils.toString(tplStream, StandardCharsets.UTF_8);
         } catch (final Exception e) {
             LOGGER.log(Level.ERROR, "Loads PWA manifest.json template failed", e);
         }

src/main/java/org/b3log/solo/processor/CategoryProcessor.java

@@ -17,6 +17,9 @@
  */
 package org.b3log.solo.processor;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
@@ -26,8 +29,6 @@ import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -59,7 +60,7 @@ public class CategoryProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CategoryProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(CategoryProcessor.class);
 
     /**
      * DataModelService.
@@ -167,7 +168,7 @@ public class CategoryProcessor {
             String categoryURI = context.pathVar("categoryURI");
             categoryURI = URLs.encode(categoryURI);
             final int currentPageNum = Paginator.getPage(context);
-            LOGGER.log(Level.DEBUG, "Category [URI={0}, currentPageNum={1}]", categoryURI, currentPageNum);
+            LOGGER.log(Level.DEBUG, "Category [URI={}, currentPageNum={}]", categoryURI, currentPageNum);
             final JSONObject category = categoryQueryService.getByURI(categoryURI);
             if (null == category) {
                 context.sendError(404);

src/main/java/org/b3log/solo/processor/CommentProcessor.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor;
 
 import freemarker.template.Template;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
@@ -25,8 +28,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.User;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.solo.model.Article;
@@ -59,7 +60,7 @@ public class CommentProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CommentProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(CommentProcessor.class);
 
     /**
      * Language service.
@@ -137,7 +138,7 @@ public class CommentProcessor {
         renderer.setJSONObject(jsonObject);
 
         if (!jsonObject.optBoolean(Keys.STATUS_CODE)) {
-            LOGGER.log(Level.WARN, "Can't add comment[msg={0}]", jsonObject.optString(Keys.MSG));
+            LOGGER.log(Level.WARN, "Can't add comment[msg={}]", jsonObject.optString(Keys.MSG));
             return;
         }
 

src/main/java/org/b3log/solo/processor/ErrorProcessor.java

@@ -18,14 +18,15 @@
 package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.Request;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.ioc.Inject;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.Locales;
 import org.b3log.solo.model.Common;
@@ -50,7 +51,7 @@ public class ErrorProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleProcessor.class);
 
     /**
      * DataModelService.
@@ -88,7 +89,7 @@ public class ErrorProcessor {
         if (StringUtils.equals("GET", context.method())) {
             final String requestURI = context.requestURI();
             final String templateName = statusCode + ".ftl";
-            LOGGER.log(Level.TRACE, "Shows error page [requestURI={0}, templateName={1}]", requestURI, templateName);
+            LOGGER.log(Level.TRACE, "Shows error page [requestURI={}, templateName={}]", requestURI, templateName);
 
             final AbstractFreeMarkerRenderer renderer = new SkinRenderer(context, "error/" + templateName);
             final Map<String, Object> dataModel = renderer.getDataModel();

src/main/java/org/b3log/solo/processor/FeedProcessor.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor;
 
 import com.vdurmont.emoji.EmojiParser;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
@@ -27,8 +30,6 @@ import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AtomRenderer;
 import org.b3log.latke.http.renderer.RssRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.User;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.service.ServiceException;
@@ -68,7 +69,7 @@ public class FeedProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(FeedProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(FeedProcessor.class);
 
     /**
      * Article query service.

src/main/java/org/b3log/solo/processor/IndexProcessor.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.*;
@@ -25,8 +28,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -62,7 +63,7 @@ public class IndexProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(IndexProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(IndexProcessor.class);
 
     /**
      * DataModelService.

src/main/java/org/b3log/solo/processor/InitCheckHandler.java

@@ -18,13 +18,14 @@
 package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.handler.Handler;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.solo.service.InitService;
 
 /**
@@ -39,7 +40,7 @@ public class InitCheckHandler implements Handler {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(InitCheckHandler.class);
+    private static final Logger LOGGER = LogManager.getLogger(InitCheckHandler.class);
 
     /**
      * Whether initialization info reported.
@@ -50,7 +51,7 @@ public class InitCheckHandler implements Handler {
     public void handle(final RequestContext context) {
         final String requestURI = context.requestURI();
         final boolean isSpiderBot = (boolean) context.attr(Keys.HttpRequest.IS_SEARCH_ENGINE_BOT);
-        LOGGER.log(Level.TRACE, "Request [URI={0}]", requestURI);
+        LOGGER.log(Level.TRACE, "Request [URI={}]", requestURI);
 
         // 禁止直接获取 robots.txt https://github.com/b3log/solo/issues/12543
         if (requestURI.startsWith("/robots.txt") && !isSpiderBot) {

src/main/java/org/b3log/solo/processor/OAuthProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import org.apache.commons.lang.RandomStringUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.Request;
@@ -27,8 +30,6 @@ import org.b3log.latke.http.Response;
 import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
 import org.b3log.latke.service.LangPropsService;
@@ -59,7 +60,7 @@ public class OAuthProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(OAuthProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(OAuthProcessor.class);
 
     /**
      * OAuth parameters - state.
@@ -207,6 +208,6 @@ public class OAuthProcessor {
 
         Solos.login(user, response);
         context.sendRedirect(referer);
-        LOGGER.log(Level.INFO, "Logged in [name={0}, remoteAddr={1}] with oauth", userName, Requests.getRemoteAddr(request));
+        LOGGER.log(Level.INFO, "Logged in [name={}, remoteAddr={}] with oauth", userName, Requests.getRemoteAddr(request));
     }
 }

src/main/java/org/b3log/solo/processor/PermalinkHandler.java

@@ -18,14 +18,15 @@
 package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.handler.Handler;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.solo.model.Article;
 import org.b3log.solo.model.Option;
@@ -48,7 +49,7 @@ public class PermalinkHandler implements Handler {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PermalinkHandler.class);
+    private static final Logger LOGGER = LogManager.getLogger(PermalinkHandler.class);
 
     /**
      * Whether initialization info reported.
@@ -72,7 +73,7 @@ public class PermalinkHandler implements Handler {
             final String contextPath = Latkes.getContextPath();
             final String permalink = StringUtils.substringAfter(requestURI, contextPath);
             if (PermalinkQueryService.invalidPermalinkFormat(permalink)) {
-                LOGGER.log(Level.DEBUG, "Skip permalink handling request [URI={0}]", permalink);
+                LOGGER.log(Level.DEBUG, "Skip permalink handling request [URI={}]", permalink);
                 context.handle();
 
                 return;
@@ -81,7 +82,7 @@ public class PermalinkHandler implements Handler {
             final ArticleRepository articleRepository = beanManager.getReference(ArticleRepository.class);
             article = articleRepository.getByPermalink(permalink);
             if (null == article) {
-                LOGGER.log(Level.DEBUG, "Not found article with permalink [{0}]", permalink);
+                LOGGER.log(Level.DEBUG, "Not found article with permalink [{}]", permalink);
                 context.handle();
 
                 return;

src/main/java/org/b3log/solo/processor/SearchProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.Request;
@@ -28,8 +31,6 @@ import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.http.renderer.TextXmlRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.Paginator;
@@ -46,6 +47,7 @@ import org.jsoup.safety.Whitelist;
 import org.owasp.encoder.Encode;
 
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -64,7 +66,7 @@ public class SearchProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(SearchProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(SearchProcessor.class);
 
     /**
      * Article query service.
@@ -108,7 +110,7 @@ public class SearchProcessor {
 
         try {
             final InputStream resourceAsStream = SearchProcessor.class.getResourceAsStream("/opensearch.xml");
-            String content = IOUtils.toString(resourceAsStream, "UTF-8");
+            String content = IOUtils.toString(resourceAsStream, StandardCharsets.UTF_8);
             final JSONObject preference = optionQueryService.getPreference();
             content = StringUtils.replace(content, "${blogTitle}", Jsoup.clean(preference.optString(Option.ID_C_BLOG_TITLE), Whitelist.none()));
             content = StringUtils.replace(content, "${blogSubtitle}", Jsoup.clean(preference.optString(Option.ID_C_BLOG_SUBTITLE), Whitelist.none()));

src/main/java/org/b3log/solo/processor/SitemapProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
@@ -27,8 +30,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.TextXmlRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.FilterOperator;
 import org.b3log.latke.repository.PropertyFilter;
 import org.b3log.latke.repository.Query;
@@ -61,7 +62,7 @@ public class SitemapProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(SitemapProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(SitemapProcessor.class);
 
     /**
      * Article repository.

src/main/java/org/b3log/solo/processor/SkinHandler.java

@@ -20,13 +20,14 @@ package org.b3log.solo.processor;
 import eu.bitwalker.useragentutils.BrowserType;
 import eu.bitwalker.useragentutils.UserAgent;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.Request;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.handler.Handler;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.util.Requests;
 import org.b3log.solo.service.OptionQueryService;
 import org.b3log.solo.service.StatisticMgmtService;
@@ -46,7 +47,7 @@ public class SkinHandler implements Handler {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(SkinHandler.class);
+    private static final Logger LOGGER = LogManager.getLogger(SkinHandler.class);
 
     @Override
     public void handle(final RequestContext context) {

src/main/java/org/b3log/solo/processor/TagProcessor.java

@@ -17,6 +17,9 @@
  */
 package org.b3log.solo.processor;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
@@ -24,8 +27,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.Paginator;
@@ -54,7 +55,7 @@ public class TagProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(TagProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(TagProcessor.class);
 
     /**
      * DataModelService.
@@ -111,7 +112,7 @@ public class TagProcessor {
         try {
             String tagTitle = context.pathVar("tagTitle");
             final int currentPageNum = Paginator.getPage(context);
-            LOGGER.log(Level.DEBUG, "Tag [title={0}, currentPageNum={1}]", tagTitle, currentPageNum);
+            LOGGER.log(Level.DEBUG, "Tag [title={}, currentPageNum={}]", tagTitle, currentPageNum);
             final JSONObject result = tagQueryService.getTagByTitle(tagTitle);
             if (null == result) {
                 context.sendError(404);

src/main/java/org/b3log/solo/processor/UserTemplateProcessor.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor;
 
 import freemarker.template.Template;
 import org.apache.commons.io.IOUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.Request;
@@ -29,8 +32,6 @@ import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.http.renderer.TextHtmlRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.Locales;
 import org.b3log.solo.model.Option;
@@ -62,7 +63,7 @@ public class UserTemplateProcessor {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleProcessor.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleProcessor.class);
 
     /**
      * DataModelService.
@@ -112,7 +113,7 @@ public class UserTemplateProcessor {
             return;
         }
 
-        LOGGER.log(Level.DEBUG, "Shows page [requestURI={0}, templateName={1}]", requestURI, templateName);
+        LOGGER.log(Level.DEBUG, "Shows page [requestURI={}, templateName={}]", requestURI, templateName);
 
         final Request request = context.getRequest();
         final Response response = context.getResponse();

src/main/java/org/b3log/solo/processor/console/AdminConsole.java

@@ -21,6 +21,9 @@ import jodd.io.ZipUtil;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.Event;
@@ -31,8 +34,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.renderer.AbstractFreeMarkerRenderer;
 import org.b3log.latke.ioc.Inject;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.model.User;
 import org.b3log.latke.plugin.ViewLoadEventData;
@@ -53,6 +54,7 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.*;
 
 /**
@@ -69,7 +71,7 @@ public class AdminConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(AdminConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(AdminConsole.class);
 
     /**
      * Language service.
@@ -280,7 +282,7 @@ public class AdminConsole {
 
         try {
             final JSONObject json = exportService.getJSONs();
-            final byte[] data = json.toString(4).getBytes("UTF-8");
+            final byte[] data = json.toString(4).getBytes(StandardCharsets.UTF_8);
 
             try (final OutputStream output = new FileOutputStream(localFile)) {
                 IOUtils.write(data, output);

src/main/java/org/b3log/solo/processor/console/ArticleConsole.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor.console;
 
 import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.Request;
@@ -27,8 +30,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
 import org.b3log.latke.ioc.Singleton;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.util.Strings;
@@ -59,7 +60,7 @@ public class ArticleConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleConsole.class);
 
     /**
      * Article management service.

src/main/java/org/b3log/solo/processor/console/CategoryConsole.java

@@ -19,6 +19,9 @@ package org.b3log.solo.processor.console;
 
 import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -26,8 +29,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.util.URLs;
@@ -61,7 +62,7 @@ public class CategoryConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CategoryConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(CategoryConsole.class);
 
     /**
      * Category management service.

src/main/java/org/b3log/solo/processor/console/CommentConsole.java

@@ -17,6 +17,9 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -24,8 +27,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.solo.model.Comment;
 import org.b3log.solo.service.CommentMgmtService;
@@ -49,7 +50,7 @@ public class CommentConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CommentConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(CommentConsole.class);
 
     /**
      * Comment query service.

src/main/java/org/b3log/solo/processor/console/LinkConsole.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor.console;
 
 import org.apache.commons.lang.StringEscapeUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -25,8 +28,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.solo.model.Common;
 import org.b3log.solo.model.Link;
@@ -50,7 +51,7 @@ public class LinkConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(LinkConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(LinkConsole.class);
 
     /**
      * Link query service.

src/main/java/org/b3log/solo/processor/console/OtherConsole.java

@@ -17,14 +17,15 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.solo.service.ArchiveDateMgmtService;
 import org.b3log.solo.service.TagMgmtService;
@@ -43,7 +44,7 @@ public class OtherConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(OtherConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(OtherConsole.class);
 
     /**
      * Tag management service.

src/main/java/org/b3log/solo/processor/console/PageConsole.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor.console;
 
 import org.apache.commons.lang.StringEscapeUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -25,8 +28,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.solo.model.Common;
@@ -52,7 +53,7 @@ public class PageConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PageConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(PageConsole.class);
 
     /**
      * User query service.

src/main/java/org/b3log/solo/processor/console/PluginConsole.java

@@ -17,6 +17,9 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -24,8 +27,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.solo.service.PluginMgmtService;
@@ -50,7 +51,7 @@ public class PluginConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PluginConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(PluginConsole.class);
 
     /**
      * Plugin query service.

src/main/java/org/b3log/solo/processor/console/PreferenceConsole.java

@@ -17,14 +17,15 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.solo.model.Option;
@@ -50,7 +51,7 @@ public class PreferenceConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PreferenceConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(PreferenceConsole.class);
 
     /**
      * Preference management service.

src/main/java/org/b3log/solo/processor/console/RepairConsole.java

@@ -17,14 +17,15 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.TextHtmlRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.ArchiveDateArticleRepository;
@@ -53,7 +54,7 @@ public class RepairConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(RepairConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(RepairConsole.class);
 
     /**
      * Option query service.

src/main/java/org/b3log/solo/processor/console/SkinConsole.java

@@ -17,6 +17,9 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.Cookie;
@@ -26,8 +29,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.solo.model.Common;
@@ -54,7 +55,7 @@ public class SkinConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(SkinConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(SkinConsole.class);
 
     /**
      * Skin management service.
@@ -112,7 +113,7 @@ public class SkinConsole {
                 final JSONObject s = new JSONObject();
                 final String name = Latkes.getSkinName(dirName);
                 if (null == name) {
-                    LOGGER.log(Level.WARN, "The directory [{0}] does not contain any skin, ignored it", dirName);
+                    LOGGER.log(Level.WARN, "The directory [{}] does not contain any skin, ignored it", dirName);
 
                     continue;
                 }

src/main/java/org/b3log/solo/processor/console/StaticSiteConsole.java

@@ -21,6 +21,9 @@ import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.HttpMethod;
 import org.b3log.latke.http.RequestContext;
@@ -29,8 +32,6 @@ import org.b3log.latke.http.annotation.RequestProcessing;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.ioc.BeanManager;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.CollectionUtils;
 import org.b3log.latke.util.Strings;
@@ -61,7 +62,7 @@ public class StaticSiteConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(StaticSiteConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(StaticSiteConsole.class);
 
     /**
      * Language service.

src/main/java/org/b3log/solo/processor/console/TagConsole.java

@@ -17,14 +17,15 @@
  */
 package org.b3log.solo.processor.console;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.solo.model.Common;
 import org.b3log.solo.model.Tag;
 import org.b3log.solo.service.TagQueryService;
@@ -46,7 +47,7 @@ public class TagConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(TagConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(TagConsole.class);
 
     /**
      * Tag query service.

src/main/java/org/b3log/solo/processor/console/UserConsole.java

@@ -18,6 +18,9 @@
 package org.b3log.solo.processor.console;
 
 import org.apache.commons.lang.StringEscapeUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
@@ -25,8 +28,6 @@ import org.b3log.latke.http.annotation.Before;
 import org.b3log.latke.http.annotation.RequestProcessor;
 import org.b3log.latke.http.renderer.JsonRenderer;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.User;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -50,7 +51,7 @@ public class UserConsole {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(UserConsole.class);
+    private static final Logger LOGGER = LogManager.getLogger(UserConsole.class);
 
     /**
      * User query service.

src/main/java/org/b3log/solo/processor/console/package-info.java

@@ -2,3 +2,4 @@
  * Console requests (Articles, Comments, Preference, etc, management) processing.
  */
 package org.b3log.solo.processor.console;
+

src/main/java/org/b3log/solo/processor/package-info.java

@@ -2,3 +2,4 @@
  * HTTP request processing.
  */
 package org.b3log.solo.processor;
+

src/main/java/org/b3log/solo/repository/ArchiveDateArticleRepository.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.repository;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Repository;
 import org.b3log.solo.model.ArchiveDate;
@@ -43,7 +44,7 @@ public class ArchiveDateArticleRepository extends AbstractRepository {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArchiveDateArticleRepository.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArchiveDateArticleRepository.class);
 
     /**
      * Public constructor.

src/main/java/org/b3log/solo/repository/ArchiveDateRepository.java

@@ -18,10 +18,11 @@
 package org.b3log.solo.repository;
 
 import org.apache.commons.lang.time.DateUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Repository;
 import org.b3log.solo.model.ArchiveDate;
@@ -44,7 +45,7 @@ public class ArchiveDateRepository extends AbstractRepository {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArchiveDateRepository.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArchiveDateRepository.class);
 
     /**
      * Archive date-Article repository.
@@ -74,7 +75,7 @@ public class ArchiveDateRepository extends AbstractRepository {
             return null;
         }
 
-        LOGGER.log(Level.TRACE, "Archive date [{0}] parsed to time [{1}]", archiveDate, time);
+        LOGGER.log(Level.TRACE, "Archive date [{}] parsed to time [{}]", archiveDate, time);
 
         Query query = new Query().setFilter(new PropertyFilter(ArchiveDate.ARCHIVE_TIME, FilterOperator.EQUAL, time)).setPageCount(1);
         JSONObject result = get(query);
@@ -88,7 +89,7 @@ public class ArchiveDateRepository extends AbstractRepository {
                 return null;
             }
 
-            LOGGER.log(Level.TRACE, "Fix archive date [{0}] parsed to time [{1}]", archiveDate, time);
+            LOGGER.log(Level.TRACE, "Fix archive date [{}] parsed to time [{}]", archiveDate, time);
 
             query = new Query().setFilter(new PropertyFilter(ArchiveDate.ARCHIVE_TIME, FilterOperator.EQUAL, time)).setPageCount(1);
             result = get(query);

src/main/java/org/b3log/solo/repository/ArticleRepository.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.repository;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Repository;
 import org.b3log.solo.cache.ArticleCache;
@@ -45,7 +46,7 @@ public class ArticleRepository extends AbstractRepository {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleRepository.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleRepository.class);
 
     /**
      * Random range.
@@ -107,7 +108,7 @@ public class ArticleRepository extends AbstractRepository {
 
         final double mid = Math.random() + RANDOM_RANGE;
 
-        LOGGER.log(Level.TRACE, "Random mid[{0}]", mid);
+        LOGGER.log(Level.TRACE, "Random mid[{}]", mid);
 
         Query query = new Query().setFilter(CompositeFilterOperator.and(
                 new PropertyFilter(Article.ARTICLE_RANDOM_DOUBLE, FilterOperator.GREATER_THAN_OR_EQUAL, mid),

src/main/java/org/b3log/solo/repository/CommentRepository.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.repository;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Repository;
 import org.b3log.solo.cache.CommentCache;
@@ -43,7 +44,7 @@ public class CommentRepository extends AbstractRepository {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CommentRepository.class);
+    private static final Logger LOGGER = LogManager.getLogger(CommentRepository.class);
 
     /**
      * Article repository.
@@ -147,7 +148,7 @@ public class CommentRepository extends AbstractRepository {
             remove(commentId);
         }
 
-        LOGGER.log(Level.DEBUG, "Removed comments[onId={0}, removedCnt={1}]", onId, comments.size());
+        LOGGER.log(Level.DEBUG, "Removed comments[onId={}, removedCnt={}]", onId, comments.size());
 
         return comments.size();
     }

src/main/java/org/b3log/solo/repository/TagArticleRepository.java

@@ -18,11 +18,12 @@
 package org.b3log.solo.repository;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Repository;
 import org.b3log.solo.model.Article;
@@ -45,7 +46,7 @@ public class TagArticleRepository extends AbstractRepository {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(TagArticleRepository.class);
+    private static final Logger LOGGER = LogManager.getLogger(TagArticleRepository.class);
 
     /**
      * Public constructor.

src/main/java/org/b3log/solo/repository/package-info.java

@@ -2,3 +2,4 @@
  * Data access.
  */
 package org.b3log.solo.repository;
+

src/main/java/org/b3log/solo/service/ArchiveDateMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.annotation.Service;
@@ -44,7 +45,7 @@ public class ArchiveDateMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArchiveDateMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArchiveDateMgmtService.class);
 
     /**
      * Archive date repository.

src/main/java/org/b3log/solo/service/ArchiveDateQueryService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.service.annotation.Service;
@@ -44,7 +45,7 @@ public class ArchiveDateQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArchiveDateQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArchiveDateQueryService.class);
 
     /**
      * Archive date repository.

src/main/java/org/b3log/solo/service/ArticleMgmtService.java

@@ -20,12 +20,13 @@ package org.b3log.solo.service;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
 import org.apache.commons.lang.time.DateUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.event.EventManager;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.LangPropsService;
@@ -61,7 +62,7 @@ public class ArticleMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleMgmtService.class);
 
     /**
      * Article query service.
@@ -390,7 +391,7 @@ public class ArticleMgmtService {
                 transaction.rollback();
             }
 
-            LOGGER.log(Level.ERROR, "Can't put the article[oId{0}] to top", articleId);
+            LOGGER.log(Level.ERROR, "Can't put the article[oId{}] to top", articleId);
             throw new ServiceException(e);
         }
     }
@@ -774,7 +775,7 @@ public class ArticleMgmtService {
             final String newTagTitle = newTag.getString(Tag.TAG_TITLE);
 
             if (!tagExists(newTagTitle, oldTags)) {
-                LOGGER.log(Level.DEBUG, "Tag need to add[title={0}]", newTagTitle);
+                LOGGER.log(Level.DEBUG, "Tag need to add[title={}]", newTagTitle);
                 tagsNeedToAdd.add(newTag);
             } else {
                 tagsUnchanged.add(newTag);
@@ -784,14 +785,14 @@ public class ArticleMgmtService {
             final String oldTagTitle = oldTag.getString(Tag.TAG_TITLE);
 
             if (!tagExists(oldTagTitle, newTags)) {
-                LOGGER.log(Level.DEBUG, "Tag dropped[title={0}]", oldTag);
+                LOGGER.log(Level.DEBUG, "Tag dropped[title={}]", oldTag);
                 tagsDropped.add(oldTag);
             } else {
                 tagsUnchanged.remove(oldTag);
             }
         }
 
-        LOGGER.log(Level.DEBUG, "Tags unchanged [{0}]", tagsUnchanged);
+        LOGGER.log(Level.DEBUG, "Tags unchanged [{}]", tagsUnchanged);
 
         final String[] tagIdsDropped = new String[tagsDropped.size()];
         for (int i = 0; i < tagIdsDropped.length; i++) {
@@ -886,7 +887,7 @@ public class ArticleMgmtService {
             String tagId;
 
             if (null == tag) {
-                LOGGER.log(Level.TRACE, "Found a new tag[title={0}] in article[title={1}]",
+                LOGGER.log(Level.TRACE, "Found a new tag[title={}] in article[title={}]",
                         tagTitle, article.optString(Article.ARTICLE_TITLE));
                 tag = new JSONObject();
                 tag.put(Tag.TAG_TITLE, tagTitle);
@@ -894,7 +895,7 @@ public class ArticleMgmtService {
                 tag.put(Keys.OBJECT_ID, tagId);
             } else {
                 tagId = tag.optString(Keys.OBJECT_ID);
-                LOGGER.log(Level.TRACE, "Found a existing tag[title={0}, id={1}] in article[title={2}]",
+                LOGGER.log(Level.TRACE, "Found a existing tag[title={}, id={}] in article[title={}]",
                         tag.optString(Tag.TAG_TITLE), tag.optString(Keys.OBJECT_ID), article.optString(Article.ARTICLE_TITLE));
                 final JSONObject tagTmp = new JSONObject();
                 tagTmp.put(Keys.OBJECT_ID, tagId);

src/main/java/org/b3log/solo/service/ArticleQueryService.java

@@ -18,12 +18,13 @@
 package org.b3log.solo.service;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
@@ -60,7 +61,7 @@ public class ArticleQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ArticleQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ArticleQueryService.class);
 
     /**
      * User repository.
@@ -326,7 +327,7 @@ public class ArticleQueryService {
             final String userId = article.getString(Article.ARTICLE_AUTHOR_ID);
             JSONObject ret = userRepository.get(userId);
             if (null == ret) {
-                LOGGER.log(Level.WARN, "Gets author of article failed, assumes the administrator is the author of this article [id={0}]",
+                LOGGER.log(Level.WARN, "Gets author of article failed, assumes the administrator is the author of this article [id={}]",
                         article.getString(Keys.OBJECT_ID));
                 // This author may be deleted by admin, use admin as the author of this article
                 ret = userRepository.getAdmin();
@@ -334,7 +335,7 @@ public class ArticleQueryService {
 
             return ret;
         } catch (final Exception e) {
-            LOGGER.log(Level.ERROR, "Gets author of article [id={0}] failed", article.optString(Keys.OBJECT_ID));
+            LOGGER.log(Level.ERROR, "Gets author of article [id={}] failed", article.optString(Keys.OBJECT_ID));
 
             throw new ServiceException(e);
         }
@@ -363,7 +364,7 @@ public class ArticleQueryService {
             }
         }
 
-        LOGGER.log(Level.WARN, "Can not find the sign [id={0}], returns a default sign [id=1]", signId);
+        LOGGER.log(Level.WARN, "Can not find the sign [id={}], returns a default sign [id=1]", signId);
 
         return defaultSign;
     }
@@ -461,7 +462,7 @@ public class ArticleQueryService {
             article.remove(Article.ARTICLE_VIEW_COUNT);
             article.remove(Article.ARTICLE_RANDOM_DOUBLE);
 
-            LOGGER.log(Level.DEBUG, "Got an article [id={0}]", articleId);
+            LOGGER.log(Level.DEBUG, "Got an article [id={}]", articleId);
 
             return ret;
         } catch (final Exception e) {

src/main/java/org/b3log/solo/service/CategoryMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.repository.annotation.Transactional;
 import org.b3log.latke.service.ServiceException;
@@ -45,7 +46,7 @@ public class CategoryMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CategoryMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(CategoryMgmtService.class);
 
     /**
      * Category repository.
@@ -87,7 +88,7 @@ public class CategoryMgmtService {
                     transaction.rollback();
                 }
 
-                LOGGER.log(Level.WARN, "Cant not find the target category of source category [order={0}]", srcCategoryOrder);
+                LOGGER.log(Level.WARN, "Cant not find the target category of source category [order={}]", srcCategoryOrder);
 
                 return;
             }

src/main/java/org/b3log/solo/service/CategoryQueryService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.repository.*;
 import org.b3log.latke.service.ServiceException;
@@ -53,7 +54,7 @@ public class CategoryQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CategoryQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(CategoryQueryService.class);
 
     /**
      * Category repository.
@@ -138,9 +139,6 @@ public class CategoryQueryService {
     public JSONObject getByURI(final String categoryURI) throws ServiceException {
         try {
             final JSONObject ret = categoryRepository.getByURI(categoryURI);
-            if (null == ret) {
-                return null;
-            }
 
             return ret;
         } catch (final RepositoryException e) {

src/main/java/org/b3log/solo/service/CommentMgmtService.java

@@ -19,12 +19,13 @@ package org.b3log.solo.service;
 
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.event.Event;
 import org.b3log.latke.event.EventManager;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.LangPropsService;
@@ -56,7 +57,7 @@ public class CommentMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CommentMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(CommentMgmtService.class);
 
     /**
      * Minimum length of comment name.
@@ -179,7 +180,7 @@ public class CommentMgmtService {
 
             String commentName = requestJSONObject.getString(Comment.COMMENT_NAME);
             if (MAX_COMMENT_NAME_LENGTH < commentName.length() || MIN_COMMENT_NAME_LENGTH > commentName.length()) {
-                LOGGER.log(Level.WARN, "Comment name is too long [{0}]", commentName);
+                LOGGER.log(Level.WARN, "Comment name is too long [{}]", commentName);
                 ret.put(Keys.MSG, langPropsService.get("nameTooLongLabel"));
 
                 return ret;
@@ -202,7 +203,7 @@ public class CommentMgmtService {
             String commentContent = requestJSONObject.optString(Comment.COMMENT_CONTENT);
 
             if (MAX_COMMENT_CONTENT_LENGTH < commentContent.length() || MIN_COMMENT_CONTENT_LENGTH > commentContent.length()) {
-                LOGGER.log(Level.WARN, "Comment conent length is invalid[{0}]", commentContent.length());
+                LOGGER.log(Level.WARN, "Comment conent length is invalid[{}]", commentContent.length());
                 ret.put(Keys.MSG, langPropsService.get("commentContentCannotEmptyLabel"));
 
                 return ret;
@@ -300,7 +301,7 @@ public class CommentMgmtService {
 
                     ret.put(Common.IS_REPLY, true);
                 } else {
-                    LOGGER.log(Level.WARN, "Not found orginal comment[id={0}] of reply[name={1}, content={2}]",
+                    LOGGER.log(Level.WARN, "Not found orginal comment[id={}] of reply[name={}, content={}]",
                             originalCommentId, commentName, commentContent);
                 }
             }

src/main/java/org/b3log/solo/service/CommentQueryService.java

@@ -18,10 +18,11 @@
 package org.b3log.solo.service;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
@@ -60,7 +61,7 @@ public class CommentQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CommentQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(CommentQueryService.class);
 
     /**
      * User service.

src/main/java/org/b3log/solo/service/CronMgmtService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.annotation.Service;
 import org.b3log.latke.util.Stopwatchs;
 import org.b3log.solo.util.Solos;
@@ -41,7 +42,7 @@ public class CronMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(CronMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(CronMgmtService.class);
 
     /**
      * Cron thread pool.

src/main/java/org/b3log/solo/service/DataModelService.java

@@ -20,6 +20,9 @@ package org.b3log.solo.service;
 import freemarker.template.Template;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.event.Event;
@@ -27,8 +30,6 @@ import org.b3log.latke.event.EventManager;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.ioc.BeanManager;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.model.Role;
@@ -68,7 +69,7 @@ public class DataModelService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(DataModelService.class);
+    private static final Logger LOGGER = LogManager.getLogger(DataModelService.class);
 
     /**
      * Article repository.
@@ -395,7 +396,7 @@ public class DataModelService {
                     if (!dateString.equals(lastDateString)) {
                         archiveDates2.add(archiveDate);
                     } else {
-                        LOGGER.log(Level.DEBUG, "Found a duplicated archive date [{0}]", dateString);
+                        LOGGER.log(Level.DEBUG, "Found a duplicated archive date [{}]", dateString);
                     }
                 }
             }
@@ -828,7 +829,7 @@ public class DataModelService {
                                  final Map<String, Object> dataModel, final JSONObject preference) throws ServiceException {
         Stopwatchs.start("Fill User Template[name=" + template.getName() + "]");
         try {
-            LOGGER.log(Level.DEBUG, "Filling user template[name{0}]", template.getName());
+            LOGGER.log(Level.DEBUG, "Filling user template[name{}]", template.getName());
 
             if (Templates.hasExpression(template, "<#list links as link>")) {
                 fillLinks(dataModel);

src/main/java/org/b3log/solo/service/ExportService.java

@@ -24,11 +24,12 @@ import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.model.User;
 import org.b3log.latke.repository.*;
@@ -48,6 +49,7 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.Statement;
@@ -67,7 +69,7 @@ public class ExportService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ExportService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ExportService.class);
 
     /**
      * Archive date repository.
@@ -235,7 +237,7 @@ public class ExportService {
         final File localFile = new File(localFilePath);
 
         try {
-            final byte[] data = sql.getBytes("UTF-8");
+            final byte[] data = sql.getBytes(StandardCharsets.UTF_8);
             try (final OutputStream output = new FileOutputStream(localFile)) {
                 IOUtils.write(data, output);
             }

src/main/java/org/b3log/solo/service/ImportService.java

@@ -20,11 +20,12 @@ package org.b3log.solo.service;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.annotation.Service;
 import org.b3log.latke.util.Strings;
 import org.b3log.solo.model.Article;
@@ -49,7 +50,7 @@ public class ImportService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(ImportService.class);
+    private static final Logger LOGGER = LogManager.getLogger(ImportService.class);
 
     /**
      * Default tag.

src/main/java/org/b3log/solo/service/InitService.java

@@ -19,11 +19,12 @@ package org.b3log.solo.service;
 
 import org.apache.commons.lang.time.DateFormatUtils;
 import org.apache.commons.lang.time.DateUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
 import org.b3log.latke.plugin.PluginManager;
@@ -61,7 +62,7 @@ public class InitService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(InitService.class);
+    private static final Logger LOGGER = LogManager.getLogger(InitService.class);
 
     /**
      * Option repository.
@@ -199,7 +200,7 @@ public class InitService {
 
         final List<CreateTableResult> createTableResults = JdbcRepositories.initAllTables();
         for (final CreateTableResult createTableResult : createTableResults) {
-            LOGGER.log(Level.DEBUG, "Creates table result [tableName={0}, isSuccess={1}]",
+            LOGGER.log(Level.DEBUG, "Creates table result [tableName={}, isSuccess={}]",
                     createTableResult.getName(), createTableResult.isSuccess());
         }
     }
@@ -388,7 +389,7 @@ public class InitService {
             final String tagTitle = tagTitle1.trim();
             final JSONObject tag = new JSONObject();
 
-            LOGGER.log(Level.TRACE, "Found a new tag[title={0}] in article[title={1}]", tagTitle, article.optString(Article.ARTICLE_TITLE));
+            LOGGER.log(Level.TRACE, "Found a new tag[title={}] in article[title={}]", tagTitle, article.optString(Article.ARTICLE_TITLE));
             tag.put(Tag.TAG_TITLE, tagTitle);
             final String tagId = tagRepository.add(tag);
             tag.put(Keys.OBJECT_ID, tagId);

src/main/java/org/b3log/solo/service/LinkMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.service.annotation.Service;
@@ -41,7 +42,7 @@ public class LinkMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(LinkMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(LinkMgmtService.class);
 
     /**
      * Link repository.
@@ -138,7 +139,7 @@ public class LinkMgmtService {
                     transaction.rollback();
                 }
 
-                LOGGER.log(Level.WARN, "Cant not find the target link of source link[order={0}]", srcLinkOrder);
+                LOGGER.log(Level.WARN, "Cant not find the target link of source link[order={}]", srcLinkOrder);
                 return;
             }
 

src/main/java/org/b3log/solo/service/LinkQueryService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.SortDirection;
@@ -47,7 +48,7 @@ public class LinkQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(LinkQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(LinkQueryService.class);
 
     /**
      * Link repository.

src/main/java/org/b3log/solo/service/OptionQueryService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.service.annotation.Service;
 import org.b3log.solo.model.Option;
@@ -39,7 +40,7 @@ public class OptionQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(OptionQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(OptionQueryService.class);
 
     /**
      * Option repository.

src/main/java/org/b3log/solo/service/PageMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.LangPropsService;
@@ -46,7 +47,7 @@ public class PageMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PageMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PageMgmtService.class);
 
     /**
      * Page repository.
@@ -133,7 +134,7 @@ public class PageMgmtService {
             pageRepository.update(pageId, newPage);
             transaction.commit();
 
-            LOGGER.log(Level.DEBUG, "Updated a page[id={0}]", pageId);
+            LOGGER.log(Level.DEBUG, "Updated a page[id={}]", pageId);
         } catch (final Exception e) {
             LOGGER.log(Level.ERROR, e.getMessage(), e);
             if (transaction.isActive()) {
@@ -247,7 +248,7 @@ public class PageMgmtService {
                     transaction.rollback();
                 }
 
-                LOGGER.log(Level.WARN, "Cant not find the target page of source page[order={0}]", srcPageOrder);
+                LOGGER.log(Level.WARN, "Cant not find the target page of source page[order={}]", srcPageOrder);
                 return;
             }
 

src/main/java/org/b3log/solo/service/PageQueryService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.SortDirection;
@@ -47,7 +48,7 @@ public class PageQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PageQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PageQueryService.class);
 
     /**
      * Page repository.

src/main/java/org/b3log/solo/service/PermalinkQueryService.java

@@ -18,10 +18,11 @@
 package org.b3log.solo.service;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.service.annotation.Service;
 import org.b3log.latke.util.Strings;
@@ -44,7 +45,7 @@ public class PermalinkQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PermalinkQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PermalinkQueryService.class);
 
     /**
      * Page repository.

src/main/java/org/b3log/solo/service/PluginMgmtService.java

@@ -18,11 +18,12 @@
 package org.b3log.solo.service;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.plugin.AbstractPlugin;
 import org.b3log.latke.plugin.PluginManager;
@@ -51,7 +52,7 @@ public class PluginMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PluginMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PluginMgmtService.class);
 
     /**
      * Plugin repository.
@@ -118,7 +119,7 @@ public class PluginMgmtService {
 
                 pluginRepository.add(pluginDesc);
 
-                LOGGER.log(Level.TRACE, "Refreshed plugin[{0}]", pluginDesc);
+                LOGGER.log(Level.TRACE, "Refreshed plugin[{}]", pluginDesc);
             }
 
         } catch (final Exception e) {

src/main/java/org/b3log/solo/service/PluginQueryService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.Plugin;
 import org.b3log.latke.plugin.AbstractPlugin;
@@ -48,7 +49,7 @@ public class PluginQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PluginQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PluginQueryService.class);
 
     /**
      * Plugin repository.

src/main/java/org/b3log/solo/service/PreferenceMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -46,7 +47,7 @@ public class PreferenceMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(PreferenceMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(PreferenceMgmtService.class);
 
     /**
      * Option query service.

src/main/java/org/b3log/solo/service/SkinMgmtService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -44,7 +45,7 @@ public class SkinMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(SkinMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(SkinMgmtService.class);
 
     /**
      * Option query service.
@@ -74,7 +75,7 @@ public class SkinMgmtService {
         final Set<String> skinDirNames = Skins.getSkinDirNames();
         final String currentSkinDirName = skin.optString(Option.ID_C_SKIN_DIR_NAME);
         if (!skinDirNames.contains(currentSkinDirName)) {
-            LOGGER.log(Level.WARN, "Not found skin [dirName={0}] configured, try to use default skin [dirName="
+            LOGGER.log(Level.WARN, "Not found skin [dirName={}] configured, try to use default skin [dirName="
                     + Option.DefaultPreference.DEFAULT_SKIN_DIR_NAME + "] instead", currentSkinDirName);
             if (!skinDirNames.contains(Option.DefaultPreference.DEFAULT_SKIN_DIR_NAME)) {
                 LOGGER.log(Level.ERROR, "Not found default skin [dirName=" + Option.DefaultPreference.DEFAULT_SKIN_DIR_NAME
@@ -88,7 +89,7 @@ public class SkinMgmtService {
 
         final String currentMobileSkinDirName = skin.optString(Option.ID_C_MOBILE_SKIN_DIR_NAME);
         if (!skinDirNames.contains(currentMobileSkinDirName)) {
-            LOGGER.log(Level.WARN, "Not found mobile skin [dirName={0}] configured, try to use default mobile skin [dirName="
+            LOGGER.log(Level.WARN, "Not found mobile skin [dirName={}] configured, try to use default mobile skin [dirName="
                     + Option.DefaultPreference.DEFAULT_MOBILE_SKIN_DIR_NAME + "] instead", currentMobileSkinDirName);
             if (!skinDirNames.contains(Option.DefaultPreference.DEFAULT_MOBILE_SKIN_DIR_NAME)) {
                 LOGGER.log(Level.ERROR, "Not found default mobile skin [dirName=" + Option.DefaultPreference.DEFAULT_MOBILE_SKIN_DIR_NAME

src/main/java/org/b3log/solo/service/StatisticMgmtService.java

@@ -17,13 +17,14 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.http.Cookie;
 import org.b3log.latke.http.Request;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.http.Response;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
@@ -63,7 +64,7 @@ public class StatisticMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(StatisticMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(StatisticMgmtService.class);
 
     /**
      * Online visitor expiration in 5 minutes.
@@ -112,11 +113,11 @@ public class StatisticMgmtService {
 
             if (currentTimeMillis > (onlineVisitor.getValue() + ONLINE_VISITOR_EXPIRATION)) {
                 iterator.remove();
-                LOGGER.log(Level.TRACE, "Removed online visitor[ip={0}]", onlineVisitor.getKey());
+                LOGGER.log(Level.TRACE, "Removed online visitor[ip={}]", onlineVisitor.getKey());
             }
         }
 
-        LOGGER.log(Level.DEBUG, "Current online visitor count [{0}]", ONLINE_VISITORS.size());
+        LOGGER.log(Level.DEBUG, "Current online visitor count [{}]", ONLINE_VISITORS.size());
     }
 
     /**
@@ -227,7 +228,7 @@ public class StatisticMgmtService {
 //                return;
 //            }
 //
-//            LOGGER.log(Level.TRACE, "Before inc blog view count is [{0}]", statistic);
+//            LOGGER.log(Level.TRACE, "Before inc blog view count is [{}]", statistic);
 //
 //            statistic.put(Option.OPTION_VALUE, statistic.optInt(Option.OPTION_VALUE) + 1);
 //
@@ -244,7 +245,7 @@ public class StatisticMgmtService {
 //            return;
 //        }
 //
-//        LOGGER.log(Level.TRACE, "Inced blog view count[statistic={0}]", statistic);
+//        LOGGER.log(Level.TRACE, "Inced blog view count[statistic={}]", statistic);
     }
 
     /**
@@ -258,9 +259,9 @@ public class StatisticMgmtService {
         }
 
         final String remoteAddr = Requests.getRemoteAddr(request);
-        LOGGER.log(Level.DEBUG, "Current request [IP={0}]", remoteAddr);
+        LOGGER.log(Level.DEBUG, "Current request [IP={}]", remoteAddr);
         ONLINE_VISITORS.put(remoteAddr, System.currentTimeMillis());
-        LOGGER.log(Level.DEBUG, "Current online visitor count [{0}]", ONLINE_VISITORS.size());
+        LOGGER.log(Level.DEBUG, "Current online visitor count [{}]", ONLINE_VISITORS.size());
     }
 
     /**

src/main/java/org/b3log/solo/service/StatisticQueryService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.FilterOperator;
 import org.b3log.latke.repository.PropertyFilter;
 import org.b3log.latke.repository.Query;
@@ -43,7 +44,7 @@ public class StatisticQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(StatisticQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(StatisticQueryService.class);
 
     /**
      * Option query service.

src/main/java/org/b3log/solo/service/TagMgmtService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.service.annotation.Service;
@@ -44,7 +45,7 @@ public class TagMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(TagMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(TagMgmtService.class);
 
     /**
      * Tag query service.

src/main/java/org/b3log/solo/service/TagQueryService.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.RepositoryException;
 import org.b3log.latke.service.ServiceException;
@@ -45,7 +46,7 @@ public class TagQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(TagQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(TagQueryService.class);
 
     /**
      * Tag repository.

src/main/java/org/b3log/solo/service/UpgradeService.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.annotation.Service;
 import org.b3log.solo.Server;
 import org.b3log.solo.model.Option;
@@ -39,7 +40,7 @@ public class UpgradeService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(UpgradeService.class);
+    private static final Logger LOGGER = LogManager.getLogger(UpgradeService.class);
 
     /**
      * Option Query Service.

src/main/java/org/b3log/solo/service/UserMgmtService.java

@@ -20,11 +20,12 @@ package org.b3log.solo.service;
 import jodd.http.HttpRequest;
 import jodd.http.HttpResponse;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
 import org.b3log.latke.repository.RepositoryException;
@@ -55,7 +56,7 @@ public class UserMgmtService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(UserMgmtService.class);
+    private static final Logger LOGGER = LogManager.getLogger(UserMgmtService.class);
 
     /**
      * Length of hashed password.

src/main/java/org/b3log/solo/service/UserQueryService.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.service;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.Inject;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.User;
 import org.b3log.latke.repository.FilterOperator;
@@ -52,7 +53,7 @@ public class UserQueryService {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(UserQueryService.class);
+    private static final Logger LOGGER = LogManager.getLogger(UserQueryService.class);
 
     /**
      * User repository.

src/main/java/org/b3log/solo/service/package-info.java

@@ -2,3 +2,4 @@
  * Services.
  */
 package org.b3log.solo.service;
+

src/main/java/org/b3log/solo/upgrade/V299_300.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.repository.jdbc.util.Connections;
 import org.b3log.latke.util.CollectionUtils;
@@ -48,7 +49,7 @@ public final class V299_300 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V299_300.class);
+    private static final Logger LOGGER = LogManager.getLogger(V299_300.class);
 
     /**
      * Performs upgrade from v2.9.9 to v3.0.0.

src/main/java/org/b3log/solo/upgrade/V300_310.java

@@ -18,11 +18,12 @@
 package org.b3log.solo.upgrade;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.repository.jdbc.util.Connections;
@@ -49,7 +50,7 @@ public final class V300_310 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V300_310.class);
+    private static final Logger LOGGER = LogManager.getLogger(V300_310.class);
 
     /**
      * Performs upgrade from v3.0.0 to v3.1.0.

src/main/java/org/b3log/solo/upgrade/V310_320.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.FilterOperator;
 import org.b3log.latke.repository.PropertyFilter;
 import org.b3log.latke.repository.Query;
@@ -49,7 +50,7 @@ public final class V310_320 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V310_320.class);
+    private static final Logger LOGGER = LogManager.getLogger(V310_320.class);
 
     /**
      * Performs upgrade from v3.1.0 to v3.2.0.

src/main/java/org/b3log/solo/upgrade/V320_330.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -38,7 +39,7 @@ public final class V320_330 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V320_330.class);
+    private static final Logger LOGGER = LogManager.getLogger(V320_330.class);
 
     /**
      * Performs upgrade from v3.2.0 to v3.3.0.

src/main/java/org/b3log/solo/upgrade/V330_340.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.repository.jdbc.util.Connections;
 import org.b3log.solo.model.Option;
@@ -44,7 +45,7 @@ public final class V330_340 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V330_340.class);
+    private static final Logger LOGGER = LogManager.getLogger(V330_340.class);
 
     /**
      * Performs upgrade from v3.3.0 to v3.4.0.

src/main/java/org/b3log/solo/upgrade/V340_350.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -38,7 +39,7 @@ public final class V340_350 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V340_350.class);
+    private static final Logger LOGGER = LogManager.getLogger(V340_350.class);
 
     /**
      * Performs upgrade from v3.4.0 to v3.5.0.

src/main/java/org/b3log/solo/upgrade/V350_360.java

@@ -17,11 +17,12 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.FilterOperator;
 import org.b3log.latke.repository.PropertyFilter;
 import org.b3log.latke.repository.Query;
@@ -52,7 +53,7 @@ public final class V350_360 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V350_360.class);
+    private static final Logger LOGGER = LogManager.getLogger(V350_360.class);
 
     /**
      * Performs upgrade from v3.5.0 to v3.6.0.

src/main/java/org/b3log/solo/upgrade/V360_361.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -37,7 +38,7 @@ public final class V360_361 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V360_361.class);
+    private static final Logger LOGGER = LogManager.getLogger(V360_361.class);
 
     /**
      * Performs upgrade from v3.6.0 to v3.6.1.

src/main/java/org/b3log/solo/upgrade/V361_362.java

@@ -18,10 +18,11 @@
 package org.b3log.solo.upgrade;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Comment;
@@ -45,7 +46,7 @@ public final class V361_362 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V361_362.class);
+    private static final Logger LOGGER = LogManager.getLogger(V361_362.class);
 
     /**
      * Performs upgrade from v3.6.1 to v3.6.2.

src/main/java/org/b3log/solo/upgrade/V362_363.java

@@ -18,10 +18,11 @@
 package org.b3log.solo.upgrade;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Query;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Article;
@@ -45,7 +46,7 @@ public final class V362_363 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V362_363.class);
+    private static final Logger LOGGER = LogManager.getLogger(V362_363.class);
 
     /**
      * Performs upgrade from v3.6.2 to v3.6.3.

src/main/java/org/b3log/solo/upgrade/V363_364.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -38,7 +39,7 @@ public final class V363_364 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V363_364.class);
+    private static final Logger LOGGER = LogManager.getLogger(V363_364.class);
 
     /**
      * Performs upgrade from v3.6.3 to v3.6.4.

src/main/java/org/b3log/solo/upgrade/V364_365.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -37,7 +38,7 @@ public final class V364_365 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V364_365.class);
+    private static final Logger LOGGER = LogManager.getLogger(V364_365.class);
 
     /**
      * Performs upgrade from v3.6.4 to v3.6.5.

src/main/java/org/b3log/solo/upgrade/V365_366.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.latke.repository.jdbc.util.Connections;
 import org.b3log.solo.model.Option;
@@ -42,7 +43,7 @@ public final class V365_366 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V365_366.class);
+    private static final Logger LOGGER = LogManager.getLogger(V365_366.class);
 
     /**
      * Performs upgrade from v3.6.5 to v3.6.6.

src/main/java/org/b3log/solo/upgrade/V366_367.java

@@ -17,10 +17,11 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.*;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.ArchiveDateArticleRepository;
@@ -41,7 +42,7 @@ public final class V366_367 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V366_367.class);
+    private static final Logger LOGGER = LogManager.getLogger(V366_367.class);
 
     /**
      * Performs upgrade from v3.6.6 to v3.6.7.

src/main/java/org/b3log/solo/upgrade/V367_368.java

@@ -17,18 +17,15 @@
  */
 package org.b3log.solo.upgrade;
 
-import org.b3log.latke.Latkes;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
-import org.b3log.latke.repository.*;
+import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
-import org.b3log.solo.repository.ArchiveDateArticleRepository;
 import org.b3log.solo.repository.OptionRepository;
 import org.json.JSONObject;
 
-import java.util.List;
-
 /**
  * Upgrade script from v3.6.7 to v3.6.8.
  *
@@ -41,7 +38,7 @@ public final class V367_368 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V367_368.class);
+    private static final Logger LOGGER = LogManager.getLogger(V367_368.class);
 
     /**
      * Performs upgrade from v3.6.7 to v3.6.8.

src/main/java/org/b3log/solo/upgrade/V368_370.java

@@ -17,9 +17,10 @@
  */
 package org.b3log.solo.upgrade;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.repository.Transaction;
 import org.b3log.solo.model.Option;
 import org.b3log.solo.repository.OptionRepository;
@@ -37,7 +38,7 @@ public final class V368_370 {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(V368_370.class);
+    private static final Logger LOGGER = LogManager.getLogger(V368_370.class);
 
     /**
      * Performs upgrade from v3.6.8 to v3.7.0.

src/main/java/org/b3log/solo/upgrade/package-info.java

@@ -2,3 +2,4 @@
  * Upgrade scripts.
  */
 package org.b3log.solo.upgrade;
+

src/main/java/org/b3log/solo/util/GitHubs.java

@@ -19,9 +19,10 @@ package org.b3log.solo.util;
 
 import jodd.http.HttpRequest;
 import jodd.http.HttpResponse;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.solo.model.Common;
 import org.json.JSONArray;
 import org.json.JSONObject;
@@ -38,7 +39,7 @@ public final class GitHubs {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(GitHubs.class);
+    private static final Logger LOGGER = LogManager.getLogger(GitHubs.class);
 
     /**
      * Gets GitHub repos.

src/main/java/org/b3log/solo/util/Images.java

@@ -20,8 +20,9 @@ package org.b3log.solo.util;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.time.DateFormatUtils;
 import org.apache.commons.lang.time.DateUtils;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -39,7 +40,7 @@ public final class Images {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(Images.class);
+    private static final Logger LOGGER = LogManager.getLogger(Images.class);
 
     /**
      * Community file service URL.

src/main/java/org/b3log/solo/util/Markdowns.java

@@ -27,10 +27,11 @@ import com.vladsch.flexmark.util.data.MutableDataSet;
 import org.apache.commons.codec.digest.DigestUtils;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.util.Callstacks;
 import org.b3log.latke.util.Stopwatchs;
@@ -47,6 +48,7 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.*;
 import java.util.concurrent.*;
 
@@ -66,7 +68,7 @@ public final class Markdowns {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(Markdowns.class);
+    private static final Logger LOGGER = LogManager.getLogger(Markdowns.class);
 
     /**
      * Markdown cache.
@@ -270,7 +272,7 @@ public final class Markdowns {
 
         String ret;
         try (final InputStream inputStream = conn.getInputStream()) {
-            ret = IOUtils.toString(inputStream, "UTF-8");
+            ret = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
         }
 
         conn.disconnect();

src/main/java/org/b3log/solo/util/Skins.java

@@ -21,14 +21,15 @@ import freemarker.template.Configuration;
 import freemarker.template.Template;
 import freemarker.template.TemplateExceptionHandler;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.Cookie;
 import org.b3log.latke.http.Request;
 import org.b3log.latke.http.RequestContext;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.service.LangPropsService;
 import org.b3log.latke.service.ServiceException;
 import org.b3log.latke.util.Locales;
@@ -56,7 +57,7 @@ public final class Skins {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(Skins.class);
+    private static final Logger LOGGER = LogManager.getLogger(Skins.class);
 
     /**
      * FreeMarker configuration.
@@ -162,7 +163,7 @@ public final class Skins {
                 final String country = Locales.getCountry(localeString);
                 final InputStream inputStream = Skins.class.getResourceAsStream("/skins/" + currentSkinDirName + "/lang/lang_" + language + '_' + country + ".properties");
                 if (null != inputStream) {
-                    LOGGER.log(Level.DEBUG, "Loading skin [dirName={0}, locale={1}]", currentSkinDirName, localeString);
+                    LOGGER.log(Level.DEBUG, "Loading skin [dirName={}, locale={}]", currentSkinDirName, localeString);
                     final Properties props = new Properties();
                     props.load(inputStream);
                     inputStream.close();
@@ -174,7 +175,7 @@ public final class Skins {
                     }
 
                     LANG_MAP.put(langName, langs);
-                    LOGGER.log(Level.DEBUG, "Loaded skin [dirName={0}, locale={1}, keyCount={2}]", currentSkinDirName, localeString, langs.size());
+                    LOGGER.log(Level.DEBUG, "Loaded skin [dirName={}, locale={}, keyCount={}]", currentSkinDirName, localeString, langs.size());
                 }
             }
 

src/main/java/org/b3log/solo/util/Solos.java

@@ -21,12 +21,13 @@ import jodd.http.HttpRequest;
 import jodd.http.HttpResponse;
 import org.apache.commons.lang.RandomStringUtils;
 import org.apache.commons.lang.StringUtils;
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.b3log.latke.Keys;
 import org.b3log.latke.Latkes;
 import org.b3log.latke.http.*;
 import org.b3log.latke.ioc.BeanManager;
-import org.b3log.latke.logging.Level;
-import org.b3log.latke.logging.Logger;
 import org.b3log.latke.model.Pagination;
 import org.b3log.latke.model.Role;
 import org.b3log.latke.model.User;
@@ -59,7 +60,7 @@ public final class Solos {
     /**
      * Logger.
      */
-    private static final Logger LOGGER = Logger.getLogger(Solos.class);
+    private static final Logger LOGGER = LogManager.getLogger(Solos.class);
 
     /**
      * Favicon API.

src/main/java/org/b3log/solo/util/package-info.java

@@ -2,3 +2,4 @@
  * Utilities.
  */
 package org.b3log.solo.util;
+