add ConfigChangeListener with optional interested keys

apollo-client/src/main/java/com/ctrip/framework/apollo/Config.java

@@ -162,12 +162,20 @@ public interface Config {
   public long getDurationProperty(String key, long defaultValue);
 
   /**
-   * Add change listener to this config instance.
+   * Add change listener to this config instance, will be notified when any key is changed in this namespace.
    *
    * @param listener the config change listener
    */
   public void addChangeListener(ConfigChangeListener listener);
 
+  /**
+   * Add change listener to this config instance, will only be notified when any of the interested keys is changed in this namespace.
+   *
+   * @param listener the config change listener
+   * @param interestedKeys the keys interested by the listener
+   */
+  public void addChangeListener(ConfigChangeListener listener, Set<String> interestedKeys);
+
   /**
    * Return a set of the property names
    *

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/AbstractConfig.java

@@ -40,10 +40,11 @@ import com.google.common.collect.Sets;
 public abstract class AbstractConfig implements Config {
   private static final Logger logger = LoggerFactory.getLogger(AbstractConfig.class);
 
-  private static ExecutorService m_executorService;
+  private static final ExecutorService m_executorService;
 
-  private List<ConfigChangeListener> m_listeners = Lists.newCopyOnWriteArrayList();
-  private ConfigUtil m_configUtil;
+  private final List<ConfigChangeListener> m_listeners = Lists.newCopyOnWriteArrayList();
+  private final Map<ConfigChangeListener, Set<String>> m_interestedKeys = Maps.newConcurrentMap();
+  private final ConfigUtil m_configUtil;
   private volatile Cache<String, Integer> m_integerCache;
   private volatile Cache<String, Long> m_longCache;
   private volatile Cache<String, Short> m_shortCache;
@@ -53,9 +54,9 @@ public abstract class AbstractConfig implements Config {
   private volatile Cache<String, Boolean> m_booleanCache;
   private volatile Cache<String, Date> m_dateCache;
   private volatile Cache<String, Long> m_durationCache;
-  private Map<String, Cache<String, String[]>> m_arrayCache;
-  private List<Cache> allCaches;
-  private AtomicLong m_configVersion; //indicate config version
+  private final Map<String, Cache<String, String[]>> m_arrayCache;
+  private final List<Cache> allCaches;
+  private final AtomicLong m_configVersion; //indicate config version
 
   static {
     m_executorService = Executors.newCachedThreadPool(ApolloThreadFactory
@@ -71,8 +72,16 @@ public abstract class AbstractConfig implements Config {
 
   @Override
   public void addChangeListener(ConfigChangeListener listener) {
+    addChangeListener(listener, null);
+  }
+
+  @Override
+  public void addChangeListener(ConfigChangeListener listener, Set<String> interestedKeys) {
     if (!m_listeners.contains(listener)) {
       m_listeners.add(listener);
+      if (interestedKeys != null && !interestedKeys.isEmpty()) {
+        m_interestedKeys.put(listener, Sets.newHashSet(interestedKeys));
+      }
     }
   }
 
@@ -395,6 +404,10 @@ public abstract class AbstractConfig implements Config {
 
   protected void fireConfigChange(final ConfigChangeEvent changeEvent) {
     for (final ConfigChangeListener listener : m_listeners) {
+      // check whether the listener is interested in this change event
+      if (!isConfigChangeListenerInterested(listener, changeEvent)) {
+        continue;
+      }
       m_executorService.submit(new Runnable() {
         @Override
         public void run() {
@@ -415,6 +428,22 @@ public abstract class AbstractConfig implements Config {
     }
   }
 
+  private boolean isConfigChangeListenerInterested(ConfigChangeListener configChangeListener, ConfigChangeEvent configChangeEvent) {
+    Set<String> interestedKeys = m_interestedKeys.get(configChangeListener);
+
+    if (interestedKeys == null || interestedKeys.isEmpty()) {
+      return true; // no interested keys means interested in all keys
+    }
+
+    for (String interestedKey : interestedKeys) {
+      if (configChangeEvent.isChanged(interestedKey)) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
   List<ConfigChange> calcPropertyChanges(String namespace, Properties previous,
                                          Properties current) {
     if (previous == null) {

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloAnnotationProcessor.java

@@ -5,8 +5,10 @@ import com.ctrip.framework.apollo.ConfigChangeListener;
 import com.ctrip.framework.apollo.ConfigService;
 import com.ctrip.framework.apollo.model.ConfigChangeEvent;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Sets;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.util.Set;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.util.ReflectionUtils;
 
@@ -51,6 +53,8 @@ public class ApolloAnnotationProcessor extends ApolloProcessor {
 
     ReflectionUtils.makeAccessible(method);
     String[] namespaces = annotation.value();
+    String[] annotatedInterestedKeys = annotation.interestedKeys();
+    Set<String> interestedKeys = annotatedInterestedKeys.length > 0 ? Sets.newHashSet(annotatedInterestedKeys) : null;
     ConfigChangeListener configChangeListener = new ConfigChangeListener() {
       @Override
       public void onChange(ConfigChangeEvent changeEvent) {
@@ -61,7 +65,11 @@ public class ApolloAnnotationProcessor extends ApolloProcessor {
     for (String namespace : namespaces) {
       Config config = ConfigService.getConfig(namespace);
 
+      if (interestedKeys == null) {
         config.addChangeListener(configChangeListener);
+      } else {
+        config.addChangeListener(configChangeListener, interestedKeys);
+      }
     }
   }
 }

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloConfigChangeListener.java

@@ -13,11 +13,17 @@ import com.ctrip.framework.apollo.core.ConfigConsts;
  *
  * <p>Usage example:</p>
  * <pre class="code">
- * //Listener on namespaces of "someNamespace" and "anotherNamespace"
+ * //Listener on namespaces of "someNamespace" and "anotherNamespace", will be notified when any key is changed
  * &#064;ApolloConfigChangeListener({"someNamespace","anotherNamespace"})
  * private void onChange(ConfigChangeEvent changeEvent) {
  *     //handle change event
  * }
+ * <br />
+ * //Listener on namespaces of "someNamespace" and "anotherNamespace", will only be notified when "someKey" or "anotherKey" is changed
+ * &#064;ApolloConfigChangeListener(value = {"someNamespace","anotherNamespace"}, interestedKeys = {"someKey", "anotherKey"})
+ * private void onChange(ConfigChangeEvent changeEvent) {
+ *     //handle change event
+ * }
  * </pre>
  *
  * @author Jason Song(song_s@ctrip.com)
@@ -30,4 +36,11 @@ public @interface ApolloConfigChangeListener {
    * Apollo namespace for the config, if not specified then default to application
    */
   String[] value() default {ConfigConsts.NAMESPACE_APPLICATION};
+
+  /**
+   * The keys interested by the listener, will only be notified if any of the interested keys is changed.
+   * <br />
+   * If not specified then will be notified when any key is changed.
+   */
+  String[] interestedKeys() default {};
 }

apollo-client/src/test/java/com/ctrip/framework/apollo/internals/DefaultConfigTest.java

@@ -2,14 +2,18 @@ package com.ctrip.framework.apollo.internals;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import java.io.File;
 import java.util.Calendar;
 import java.util.Date;
+import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 import java.util.Collections;
@@ -647,6 +651,56 @@ public class DefaultConfigTest {
     assertEquals(PropertyChangeType.ADDED, newKeyChange.getChangeType());
   }
 
+  @Test
+  public void testFireConfigChangeWithInterestedKeys() throws Exception {
+    String someKeyChanged = "someKeyChanged";
+    String anotherKeyChanged = "anotherKeyChanged";
+    String someKeyNotChanged = "someKeyNotChanged";
+    String someNamespace = "someNamespace";
+    Map<String, ConfigChange> changes = Maps.newHashMap();
+    changes.put(someKeyChanged, mock(ConfigChange.class));
+    changes.put(anotherKeyChanged, mock(ConfigChange.class));
+    ConfigChangeEvent someChangeEvent = new ConfigChangeEvent(someNamespace, changes);
+
+    final SettableFuture<ConfigChangeEvent> interestedInAllKeysFuture = SettableFuture.create();
+    ConfigChangeListener interestedInAllKeys = new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        interestedInAllKeysFuture.set(changeEvent);
+      }
+    };
+
+    final SettableFuture<ConfigChangeEvent> interestedInSomeKeyFuture = SettableFuture.create();
+    ConfigChangeListener interestedInSomeKey = new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        interestedInSomeKeyFuture.set(changeEvent);
+      }
+    };
+
+    final SettableFuture<ConfigChangeEvent> interestedInSomeKeyNotChangedFuture = SettableFuture.create();
+    ConfigChangeListener interestedInSomeKeyNotChanged = new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        interestedInSomeKeyNotChangedFuture.set(changeEvent);
+      }
+    };
+
+    DefaultConfig config = new DefaultConfig(someNamespace, mock(ConfigRepository.class));
+
+    config.addChangeListener(interestedInAllKeys);
+    config.addChangeListener(interestedInSomeKey, Sets.newHashSet(someKeyChanged));
+    config.addChangeListener(interestedInSomeKeyNotChanged, Sets.newHashSet(someKeyNotChanged));
+
+    config.fireConfigChange(someChangeEvent);
+
+    ConfigChangeEvent changeEvent = interestedInAllKeysFuture.get(500, TimeUnit.MILLISECONDS);
+
+    assertEquals(someChangeEvent, changeEvent);
+    assertEquals(someChangeEvent, interestedInSomeKeyFuture.get(500, TimeUnit.MILLISECONDS));
+    assertFalse(interestedInSomeKeyNotChangedFuture.isDone());
+  }
+
   @Test
   public void testGetPropertyNames() {
     String someKeyPrefix = "someKey";

apollo-client/src/test/java/com/ctrip/framework/apollo/spring/JavaConfigAnnotationTest.java

 package com.ctrip.framework.apollo.spring;
 
+import static java.util.Arrays.asList;
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
-
-import java.util.List;
-
-import org.junit.Test;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
-import org.springframework.beans.factory.BeanCreationException;
-import org.springframework.context.annotation.AnnotationConfigApplicationContext;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 import com.ctrip.framework.apollo.Config;
 import com.ctrip.framework.apollo.ConfigChangeListener;
@@ -23,6 +16,17 @@ import com.ctrip.framework.apollo.spring.annotation.ApolloConfig;
 import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
 import com.ctrip.framework.apollo.spring.annotation.EnableApolloConfig;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import java.util.List;
+import java.util.Set;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 
 /**
  * @author Jason Song(song_s@ctrip.com)
@@ -200,6 +204,39 @@ public class JavaConfigAnnotationTest extends AbstractSpringIntegrationTest {
     assertEquals(someEvent, bean.getSomeChangeEvent());
   }
 
+  @Test
+  public void testApolloConfigChangeListenerWithInterestedKeys() throws Exception {
+    Config applicationConfig = mock(Config.class);
+    Config fxApolloConfig = mock(Config.class);
+
+    mockConfig(ConfigConsts.NAMESPACE_APPLICATION, applicationConfig);
+    mockConfig(FX_APOLLO_NAMESPACE, fxApolloConfig);
+
+    TestApolloConfigChangeListenerWithInterestedKeysBean bean = getBean(
+        TestApolloConfigChangeListenerWithInterestedKeysBean.class, AppConfig8.class);
+
+    final ArgumentCaptor<Set> applicationConfigInterestedKeys = ArgumentCaptor.forClass(Set.class);
+    final ArgumentCaptor<Set> fxApolloConfigInterestedKeys = ArgumentCaptor.forClass(Set.class);
+
+    verify(applicationConfig, times(2))
+        .addChangeListener(any(ConfigChangeListener.class), applicationConfigInterestedKeys.capture());
+
+    verify(fxApolloConfig, times(1))
+        .addChangeListener(any(ConfigChangeListener.class), fxApolloConfigInterestedKeys.capture());
+
+    assertEquals(2, applicationConfigInterestedKeys.getAllValues().size());
+
+    Set<String> result = Sets.newHashSet();
+    for (Set interestedKeys : applicationConfigInterestedKeys.getAllValues()) {
+      result.addAll(interestedKeys);
+    }
+    assertEquals(Sets.newHashSet("someKey", "anotherKey"), result);
+
+    assertEquals(1, fxApolloConfigInterestedKeys.getAllValues().size());
+
+    assertEquals(asList(Sets.newHashSet("anotherKey")), fxApolloConfigInterestedKeys.getAllValues());
+  }
+
   private <T> T getBean(Class<T> beanClass, Class<?>... annotatedClasses) {
     AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(annotatedClasses);
 
@@ -269,6 +306,15 @@ public class JavaConfigAnnotationTest extends AbstractSpringIntegrationTest {
     }
   }
 
+  @Configuration
+  @EnableApolloConfig
+  static class AppConfig8 {
+    @Bean
+    public TestApolloConfigChangeListenerWithInterestedKeysBean bean() {
+      return new TestApolloConfigChangeListenerWithInterestedKeysBean();
+    }
+  }
+
   static class TestApolloConfigBean1 {
     @ApolloConfig
     private Config config;
@@ -365,4 +411,16 @@ public class JavaConfigAnnotationTest extends AbstractSpringIntegrationTest {
       return someChangeEvent;
     }
   }
+
+  static class TestApolloConfigChangeListenerWithInterestedKeysBean {
+
+    @ApolloConfigChangeListener(interestedKeys = {"someKey"})
+    private void someOnChange(ConfigChangeEvent changeEvent) {}
+
+    @ApolloConfigChangeListener(value = {ConfigConsts.NAMESPACE_APPLICATION, FX_APOLLO_NAMESPACE},
+        interestedKeys = {"anotherKey"})
+    private void anotherOnChange(ConfigChangeEvent changeEvent) {
+
+    }
+  }
 }

apollo-client/src/test/java/com/ctrip/framework/apollo/spring/XMLConfigAnnotationTest.java

 package com.ctrip.framework.apollo.spring;
 
+import static java.util.Arrays.asList;
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
+import com.google.common.collect.Sets;
 import java.util.List;
 
+import java.util.Set;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 import org.springframework.beans.factory.BeanCreationException;
@@ -125,6 +131,39 @@ public class XMLConfigAnnotationTest extends AbstractSpringIntegrationTest {
     getBean("spring/XmlConfigAnnotationTest5.xml", TestApolloConfigChangeListenerBean3.class);
   }
 
+  @Test
+  public void testApolloConfigChangeListenerWithInterestedKeys() throws Exception {
+    Config applicationConfig = mock(Config.class);
+    Config fxApolloConfig = mock(Config.class);
+
+    mockConfig(ConfigConsts.NAMESPACE_APPLICATION, applicationConfig);
+    mockConfig(FX_APOLLO_NAMESPACE, fxApolloConfig);
+
+    TestApolloConfigChangeListenerWithInterestedKeysBean bean = getBean(
+        "spring/XmlConfigAnnotationTest6.xml", TestApolloConfigChangeListenerWithInterestedKeysBean.class);
+
+    final ArgumentCaptor<Set> applicationConfigInterestedKeys = ArgumentCaptor.forClass(Set.class);
+    final ArgumentCaptor<Set> fxApolloConfigInterestedKeys = ArgumentCaptor.forClass(Set.class);
+
+    verify(applicationConfig, times(2))
+        .addChangeListener(any(ConfigChangeListener.class), applicationConfigInterestedKeys.capture());
+
+    verify(fxApolloConfig, times(1))
+        .addChangeListener(any(ConfigChangeListener.class), fxApolloConfigInterestedKeys.capture());
+
+    assertEquals(2, applicationConfigInterestedKeys.getAllValues().size());
+
+    Set<String> result = Sets.newHashSet();
+    for (Set interestedKeys : applicationConfigInterestedKeys.getAllValues()) {
+      result.addAll(interestedKeys);
+    }
+    assertEquals(Sets.newHashSet("someKey", "anotherKey"), result);
+
+    assertEquals(1, fxApolloConfigInterestedKeys.getAllValues().size());
+
+    assertEquals(asList(Sets.newHashSet("anotherKey")), fxApolloConfigInterestedKeys.getAllValues());
+  }
+
   private <T> T getBean(String xmlLocation, Class<T> beanClass) {
     ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(xmlLocation);
 
@@ -204,4 +243,15 @@ public class XMLConfigAnnotationTest extends AbstractSpringIntegrationTest {
     }
   }
 
+  static class TestApolloConfigChangeListenerWithInterestedKeysBean {
+
+    @ApolloConfigChangeListener(interestedKeys = {"someKey"})
+    private void someOnChange(ConfigChangeEvent changeEvent) {}
+
+    @ApolloConfigChangeListener(value = {ConfigConsts.NAMESPACE_APPLICATION, FX_APOLLO_NAMESPACE},
+        interestedKeys = {"anotherKey"})
+    private void anotherOnChange(ConfigChangeEvent changeEvent) {
+
+    }
+  }
 }

apollo-client/src/test/resources/spring/XmlConfigAnnotationTest6.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:apollo="http://www.ctrip.com/schema/apollo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
+       http://www.ctrip.com/schema/apollo http://www.ctrip.com/schema/apollo.xsd">
+    <apollo:config/>
+
+    <bean class="com.ctrip.framework.apollo.spring.XMLConfigAnnotationTest.TestApolloConfigChangeListenerWithInterestedKeysBean"/>
+</beans>