增强Criteria的链式调用，添加andIf(boolean addIf, CriteriaAdd add)方法，实现链式调用中按条件增加查询语句

README.md

@@ -7,7 +7,7 @@
 * 查询单条数据插件
 * MySQL分页插件
 * 数据Model链式构建插件
-* Example Criteria 增强插件
+* Example Criteria 增强插件(example,andIf)
 * Example 目标包修改插件
   
 ---------------------------------------
@@ -141,8 +141,9 @@ public class Test {
     }
 }
 ```
-### 4. Example Criteria 增强插件
-表Example增加Criteria的快速返回example()方法。  
+### 4. Example Criteria 增强插件(example,andIf)
+* 表Example增加Criteria的快速返回example()方法。  
+* Criteria链式调用增强，以前如果有按条件增加的查询语句会打乱链式查询构建，现在有了andIf(boolean ifAdd, CriteriaAdd add)方法可一直使用链式调用下去。  
 插件：
 ```xml
 <!-- Example Criteria 增强插件 -->
@@ -152,12 +153,51 @@ public class Test {
 ```java
 public class Test {
     public static void main(String[] args) {
+        // -----------------------------------example-----------------------------------
         // 表Example.Criteria增加了工厂方法example()支持，使用后可链式构建查询条件使用example()返回Example对象
         TbExample ex = new TbExample()
-                   .createCriteria()
-                   .andField1EqualTo(1)
-                   .andField2LessThan(100)
-                   .example();
+                    .createCriteria()
+                    .andField1EqualTo(1)
+                    .andField2EqualTo("xxx")
+                    .example();
+        this.tbMapper.selectByExample(ex);
+        
+        // -----------------------------------andIf-----------------------------------
+        // Criteria增强了链式调用，现在一些按条件增加的查询条件不会打乱链式调用了
+        // old
+        TbExample oldEx = new TbExample();
+        TbExample.Criteria criteria = oldEx
+                .createCriteria()
+                .andField1EqualTo(1)
+                .andField2EqualTo("xxx");
+        // 如果随机数大于0.5，附加Field3查询条件
+        if (Math.random() > 0.5){
+            criteria.andField3EqualTo(2)
+                    .andField4EqualTo(new Date());
+        }
+        this.tbMapper.selectByExample(oldEx);
+
+        // new
+        TbExample newEx;
+        newEx = new TbExample()
+                .createCriteria()
+                .andField1EqualTo(1)
+                .andField2EqualTo("xxx")
+                // 如果随机数大于0.5，附加Field3查询条件
+                .andIf(Math.random() > 0.5, new TbExample.Criteria.CriteriaAdd() {
+                    @Override
+                    public TbExample.Criteria add(TbExample.Criteria add) {
+                        return add.andField3EqualTo(2)
+                                .andField4EqualTo(new Date());
+                    }
+                })
+                // 当然最简洁的写法是采用java8的Lambda表达式，当然你的项目是Java8+
+                .andIf(Math.random() > 0.5, add -> add
+                        .andField3EqualTo(2)
+                        .andField4EqualTo(new Date())
+                )
+                .example();
+        this.tbMapper.selectByExample(newEx);
     }
 }
 ```

src/main/java/com/itfsw/mybatis/generator/plugins/CriteriaBuilderPlugin.java

@@ -17,6 +17,8 @@
 package com.itfsw.mybatis.generator.plugins;
 
 import com.itfsw.mybatis.generator.plugins.utils.CommentTools;
+import com.itfsw.mybatis.generator.plugins.utils.InnerInterface;
+import com.itfsw.mybatis.generator.plugins.utils.InnerInterfaceWrapperToInnerClass;
 import org.mybatis.generator.api.IntrospectedTable;
 import org.mybatis.generator.api.PluginAdapter;
 import org.mybatis.generator.api.dom.java.*;
@@ -55,7 +57,10 @@ public class CriteriaBuilderPlugin extends PluginAdapter {
         List<InnerClass> innerClasses = topLevelClass.getInnerClasses();
         for (InnerClass innerClass : innerClasses) {
             if ("Criteria".equals(innerClass.getType().getShortName())) {
+                // 工厂方法
                 addFactoryMethodToCriteria(topLevelClass, innerClass, introspectedTable);
+                // andIf
+                addAndIfMethodToCriteria(topLevelClass, innerClass, introspectedTable);
             }
         }
 
@@ -100,4 +105,45 @@ public class CriteriaBuilderPlugin extends PluginAdapter {
         innerClass.addMethod(method);
         logger.debug("itfsw:CriteriaBuilder增加工厂方法example");
     }
+
+
+    /**
+     * 增强Criteria的链式调用，添加andIf(boolean addIf, CriteriaAdd add)方法，实现链式调用中按条件增加查询语句
+     *
+     * @param topLevelClass
+     * @param innerClass
+     * @param introspectedTable
+     */
+    private void addAndIfMethodToCriteria(TopLevelClass topLevelClass, InnerClass innerClass, IntrospectedTable introspectedTable){
+        // 添加接口CriteriaAdd
+        InnerInterface criteriaAddInterface = new InnerInterface("ICriteriaAdd");
+        criteriaAddInterface.setVisibility(JavaVisibility.PUBLIC);
+        CommentTools.addInterfaceComment(criteriaAddInterface, introspectedTable);
+
+        // ICriteriaAdd增加接口add
+        Method addMethod = new Method("add");
+        addMethod.setReturnType(innerClass.getType());
+        addMethod.addParameter(new Parameter(innerClass.getType(), "add"));
+        CommentTools.addGeneralMethodComment(addMethod, introspectedTable);
+        criteriaAddInterface.addMethod(addMethod);
+        logger.debug("itfsw:Criteria.ICriteriaAdd增加接口add");
+
+        InnerClass innerClassWrapper = new InnerInterfaceWrapperToInnerClass(criteriaAddInterface);
+        innerClass.addInnerClass(innerClassWrapper);
+
+        // 添加andIf方法
+        Method method = new Method("andIf");
+        method.setVisibility(JavaVisibility.PUBLIC);
+        method.setReturnType(innerClass.getType());
+        method.addParameter(new Parameter(FullyQualifiedJavaType.getBooleanPrimitiveInstance(), "ifAdd"));
+        method.addParameter(new Parameter(criteriaAddInterface.getType(), "add"));
+
+        method.addBodyLine("if (ifAdd) {");
+        method.addBodyLine("add.add(this);");
+        method.addBodyLine("}");
+        method.addBodyLine("return this;");
+        CommentTools.addGeneralMethodComment(method, introspectedTable);
+        innerClass.addMethod(method);
+        logger.debug("itfsw:Criteria增加方法andIf");
+    }
 }

src/main/java/com/itfsw/mybatis/generator/plugins/utils/CommentTools.java

@@ -19,6 +19,7 @@ package com.itfsw.mybatis.generator.plugins.utils;
 import org.mybatis.generator.api.IntrospectedTable;
 import org.mybatis.generator.api.dom.java.Field;
 import org.mybatis.generator.api.dom.java.InnerClass;
+import org.mybatis.generator.api.dom.java.Interface;
 import org.mybatis.generator.api.dom.java.Method;
 import org.mybatis.generator.api.dom.xml.TextElement;
 import org.mybatis.generator.api.dom.xml.XmlElement;
@@ -111,4 +112,24 @@ public class CommentTools {
 
         xmlElement.addElement(new TextElement("-->")); //$NON-NLS-1$
     }
+
+    /**
+     * 生成通用接口注解
+     *
+     * @param interf 接口
+     * @param introspectedTable 表
+     */
+    public static void addInterfaceComment(Interface interf, IntrospectedTable introspectedTable) {
+        StringBuilder sb = new StringBuilder();
+        interf.addJavaDocLine("/**"); //$NON-NLS-1$
+        interf.addJavaDocLine(" * 这是Mybatis Generator拓展插件生成的接口(请勿删除)."); //$NON-NLS-1$
+        sb.append(" * This class corresponds to the database table "); //$NON-NLS-1$
+        sb.append(introspectedTable.getFullyQualifiedTable());
+        interf.addJavaDocLine(sb.toString());
+        interf.addJavaDocLine(" *");
+        interf.addJavaDocLine(" * "+MergeConstants.NEW_ELEMENT_TAG);
+        interf.addJavaDocLine(" * @author hewei");
+        interf.addJavaDocLine(" */"); //$NON-NLS-1$
+    }
+
 }

src/main/java/com/itfsw/mybatis/generator/plugins/utils/InnerInterface.java

+/*
+ *
+ *  * Copyright (c) 2014.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *     http://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ */
+
+package com.itfsw.mybatis.generator.plugins.utils;
+
+import org.mybatis.generator.api.dom.OutputUtilities;
+import org.mybatis.generator.api.dom.java.*;
+
+import java.util.Iterator;
+import java.util.Set;
+
+import static org.mybatis.generator.api.dom.OutputUtilities.*;
+import static org.mybatis.generator.internal.util.StringUtility.stringHasValue;
+
+/**
+ * ---------------------------------------------------------------------------
+ * 内部接口
+ * ---------------------------------------------------------------------------
+ * @author: hewei
+ * @time:2017/1/12 17:53
+ * ---------------------------------------------------------------------------
+ */
+public class InnerInterface extends Interface{
+    public InnerInterface(FullyQualifiedJavaType type) {
+        super(type);
+    }
+
+    public InnerInterface(String type) {
+        super(type);
+    }
+
+    /**
+     * 格式化后内容，因为是内部接口，需要增加缩进
+     *
+     * @param indentLevel the indent level
+     * @param compilationUnit the compilation unit
+     * @return the formatted content
+     */
+    public String getFormattedContent(int indentLevel, CompilationUnit compilationUnit) {
+        StringBuilder sb = new StringBuilder();
+
+        for (String commentLine : getFileCommentLines()) {
+            sb.append(commentLine);
+            newLine(sb);
+        }
+
+        if (stringHasValue(getType().getPackageName())) {
+            sb.append("package "); //$NON-NLS-1$
+            sb.append(getType().getPackageName());
+            sb.append(';');
+            newLine(sb);
+            newLine(sb);
+        }
+
+        for (String staticImport : getStaticImports()) {
+            sb.append("import static "); //$NON-NLS-1$
+            sb.append(staticImport);
+            sb.append(';');
+            newLine(sb);
+        }
+
+        if (getStaticImports().size() > 0) {
+            newLine(sb);
+        }
+
+        Set<String> importStrings = calculateImports(getImportedTypes());
+        for (String importString : importStrings) {
+            sb.append(importString);
+            newLine(sb);
+        }
+
+        if (importStrings.size() > 0) {
+            newLine(sb);
+        }
+
+        addFormattedJavadoc(sb, indentLevel);
+        addFormattedAnnotations(sb, indentLevel);
+
+        OutputUtilities.javaIndent(sb, indentLevel);
+
+        sb.append(getVisibility().getValue());
+
+        if (isFinal()) {
+            sb.append("final "); //$NON-NLS-1$
+        }
+
+        sb.append("interface "); //$NON-NLS-1$
+        sb.append(getType().getShortName());
+
+        if (getSuperInterfaceTypes().size() > 0) {
+            sb.append(" extends "); //$NON-NLS-1$
+
+            boolean comma = false;
+            for (FullyQualifiedJavaType fqjt : getSuperInterfaceTypes()) {
+                if (comma) {
+                    sb.append(", "); //$NON-NLS-1$
+                } else {
+                    comma = true;
+                }
+
+                sb.append(JavaDomUtils.calculateTypeName(this, fqjt));
+            }
+        }
+
+        sb.append(" {"); //$NON-NLS-1$
+        indentLevel++;
+
+        Iterator<Method> mtdIter = getMethods().iterator();
+        while (mtdIter.hasNext()) {
+            newLine(sb);
+            Method method = mtdIter.next();
+            sb.append(method.getFormattedContent(indentLevel, true, this));
+            if (mtdIter.hasNext()) {
+                newLine(sb);
+            }
+        }
+
+        indentLevel--;
+        newLine(sb);
+        javaIndent(sb, indentLevel);
+        sb.append('}');
+
+        return sb.toString();
+    }
+}

src/main/java/com/itfsw/mybatis/generator/plugins/utils/InnerInterfaceWrapperToInnerClass.java

+/*
+ *
+ *  * Copyright (c) 2014.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *     http://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ */
+
+package com.itfsw.mybatis.generator.plugins.utils;
+
+import org.mybatis.generator.api.dom.java.CompilationUnit;
+import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
+import org.mybatis.generator.api.dom.java.InnerClass;
+
+/**
+ * ---------------------------------------------------------------------------
+ * 把InnerInterface包装成InnerClass(Mybatis Generator 没有提供内部接口实现)
+ * ---------------------------------------------------------------------------
+ * @author: hewei
+ * @time:2017/1/12 17:40
+ * ---------------------------------------------------------------------------
+ */
+public class InnerInterfaceWrapperToInnerClass extends InnerClass{
+    private InnerInterface innerInterface;  // 内部接口
+
+
+    public InnerInterfaceWrapperToInnerClass(FullyQualifiedJavaType type) {
+        super(type);
+    }
+
+    public InnerInterfaceWrapperToInnerClass(String typeName) {
+        super(typeName);
+    }
+
+    public InnerInterfaceWrapperToInnerClass(InnerInterface innerInterface){
+        super(innerInterface.getType());
+        this.innerInterface = innerInterface;
+    }
+
+    /**
+     * 重写获取Java内容方法，调用InnerInterface的实现
+     *
+     * @param indentLevel
+     * @param compilationUnit
+     * @return
+     */
+    @Override
+    public String getFormattedContent(int indentLevel, CompilationUnit compilationUnit) {
+        return this.innerInterface.getFormattedContent(indentLevel, compilationUnit);
+    }
+}