Merge pull request #606 from nobodyiam/configfile-change-listener

add config file change listener

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

@@ -29,4 +29,11 @@ public interface ConfigFile {
    * @return the config file format enum
    */
   ConfigFileFormat getConfigFileFormat();
+
+  /**
+   * Add change listener to this config file instance.
+   *
+   * @param listener the config file change listener
+   */
+  void addChangeListener(ConfigFileChangeListener listener);
 }

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

+package com.ctrip.framework.apollo;
+
+import com.ctrip.framework.apollo.model.ConfigFileChangeEvent;
+
+/**
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public interface ConfigFileChangeListener {
+  /**
+   * Invoked when there is any config change for the namespace.
+   * @param changeEvent the event for this change
+   */
+  void onChange(ConfigFileChangeEvent changeEvent);
+}

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

 package com.ctrip.framework.apollo.internals;
 
+import java.util.List;
+import java.util.Objects;
 import java.util.Properties;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.ctrip.framework.apollo.ConfigFile;
+import com.ctrip.framework.apollo.ConfigFileChangeListener;
+import com.ctrip.framework.apollo.core.utils.ApolloThreadFactory;
+import com.ctrip.framework.apollo.enums.PropertyChangeType;
+import com.ctrip.framework.apollo.model.ConfigFileChangeEvent;
 import com.ctrip.framework.apollo.tracer.Tracer;
+import com.ctrip.framework.apollo.tracer.spi.Transaction;
 import com.ctrip.framework.apollo.util.ExceptionUtil;
+import com.google.common.collect.Lists;
 
 /**
  * @author Jason Song(song_s@ctrip.com)
  */
 public abstract class AbstractConfigFile implements ConfigFile, RepositoryChangeListener {
   private static final Logger logger = LoggerFactory.getLogger(AbstractConfigFile.class);
+  private static ExecutorService m_executorService;
   protected ConfigRepository m_configRepository;
   protected String m_namespace;
   protected AtomicReference<Properties> m_configProperties;
+  private List<ConfigFileChangeListener> m_listeners = Lists.newCopyOnWriteArrayList();
+
+  static {
+    m_executorService = Executors.newCachedThreadPool(ApolloThreadFactory
+        .create("ConfigFile", true));
+  }
 
   public AbstractConfigFile(String namespace, ConfigRepository configRepository) {
     m_configRepository = configRepository;
@@ -45,6 +62,8 @@ public abstract class AbstractConfigFile implements ConfigFile, RepositoryChange
     return m_namespace;
   }
 
+  protected abstract void update(Properties newProperties);
+
   @Override
   public synchronized void onRepositoryChange(String namespace, Properties newProperties) {
     if (newProperties.equals(m_configProperties.get())) {
@@ -53,9 +72,51 @@ public abstract class AbstractConfigFile implements ConfigFile, RepositoryChange
     Properties newConfigProperties = new Properties();
     newConfigProperties.putAll(newProperties);
 
-    m_configProperties.set(newConfigProperties);
+    String oldValue = getContent();
+
+    update(newProperties);
+
+    String newValue = getContent();
+
+    PropertyChangeType changeType = PropertyChangeType.MODIFIED;
+
+    if (oldValue == null) {
+      changeType = PropertyChangeType.ADDED;
+    } else if (newValue == null) {
+      changeType = PropertyChangeType.DELETED;
+    }
+
+    this.fireConfigChange(new ConfigFileChangeEvent(m_namespace, oldValue, newValue, changeType));
 
     Tracer.logEvent("Apollo.Client.ConfigChanges", m_namespace);
   }
 
+  @Override
+  public void addChangeListener(ConfigFileChangeListener listener) {
+    if (!m_listeners.contains(listener)) {
+      m_listeners.add(listener);
+    }
+  }
+
+  private void fireConfigChange(final ConfigFileChangeEvent changeEvent) {
+    for (final ConfigFileChangeListener listener : m_listeners) {
+      m_executorService.submit(new Runnable() {
+        @Override
+        public void run() {
+          String listenerName = listener.getClass().getName();
+          Transaction transaction = Tracer.newTransaction("Apollo.ConfigFileChangeListener", listenerName);
+          try {
+            listener.onChange(changeEvent);
+            transaction.setStatus(Transaction.SUCCESS);
+          } catch (Throwable ex) {
+            transaction.setStatus(ex);
+            Tracer.logError(ex);
+            logger.error("Failed to invoke config file change listener {}", listenerName, ex);
+          } finally {
+            transaction.complete();
+          }
+        }
+      });
+    }
+  }
 }

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

 package com.ctrip.framework.apollo.internals;
 
 import com.ctrip.framework.apollo.core.ConfigConsts;
+import java.util.Properties;
 
 /**
  * @author Jason Song(song_s@ctrip.com)
  */
 public abstract class PlainTextConfigFile extends AbstractConfigFile {
+
   public PlainTextConfigFile(String namespace, ConfigRepository configRepository) {
     super(namespace, configRepository);
   }
@@ -25,4 +27,9 @@ public abstract class PlainTextConfigFile extends AbstractConfigFile {
     }
     return m_configProperties.get().containsKey(ConfigConsts.CONFIG_FILE_CONTENT_KEY);
   }
+
+  @Override
+  protected void update(Properties newProperties) {
+    m_configProperties.set(newProperties);
+  }
 }

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

@@ -25,6 +25,12 @@ public class PropertiesConfigFile extends AbstractConfigFile {
     m_contentCache = new AtomicReference<>();
   }
 
+  @Override
+  protected void update(Properties newProperties) {
+    m_configProperties.set(newProperties);
+    m_contentCache.set(null);
+  }
+
   @Override
   public String getContent() {
     if (m_contentCache.get() == null) {
@@ -60,9 +66,4 @@ public class PropertiesConfigFile extends AbstractConfigFile {
     return ConfigFileFormat.Properties;
   }
 
-  @Override
-  public synchronized void onRepositoryChange(String namespace, Properties newProperties) {
-    super.onRepositoryChange(namespace, newProperties);
-    m_contentCache.set(null);
-  }
 }

apollo-client/src/main/java/com/ctrip/framework/apollo/model/ConfigFileChangeEvent.java

+package com.ctrip.framework.apollo.model;
+
+import com.ctrip.framework.apollo.enums.PropertyChangeType;
+
+/**
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ConfigFileChangeEvent {
+  private final String namespace;
+  private final String oldValue;
+  private final String newValue;
+  private final PropertyChangeType changeType;
+
+  /**
+   * Constructor.
+   *
+   * @param namespace the namespace of the config file change event
+   * @param oldValue the value before change
+   * @param newValue the value after change
+   * @param changeType the change type
+   */
+  public ConfigFileChangeEvent(String namespace, String oldValue, String newValue,
+      PropertyChangeType changeType) {
+    this.namespace = namespace;
+    this.oldValue = oldValue;
+    this.newValue = newValue;
+    this.changeType = changeType;
+  }
+
+  public String getNamespace() {
+    return namespace;
+  }
+
+  public String getOldValue() {
+    return oldValue;
+  }
+
+  public String getNewValue() {
+    return newValue;
+  }
+
+  public PropertyChangeType getChangeType() {
+    return changeType;
+  }
+
+  @Override
+  public String toString() {
+    final StringBuilder sb = new StringBuilder("ConfigFileChangeEvent{");
+    sb.append("namespace='").append(namespace).append('\'');
+    sb.append(", oldValue='").append(oldValue).append('\'');
+    sb.append(", newValue='").append(newValue).append('\'');
+    sb.append(", changeType=").append(changeType);
+    sb.append('}');
+    return sb.toString();
+  }
+}

apollo-client/src/test/java/com/ctrip/framework/apollo/ConfigServiceTest.java

@@ -132,6 +132,11 @@ public class ConfigServiceTest {
     public ConfigFileFormat getConfigFileFormat() {
       return m_configFileFormat;
     }
+
+    @Override
+    public void addChangeListener(ConfigFileChangeListener listener) {
+
+    }
   }
 
   public static class MockConfigFactory implements ConfigFactory {

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

@@ -5,6 +5,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
 
+import java.util.Properties;
 import java.util.Set;
 
 import org.junit.Before;
@@ -110,6 +111,11 @@ public class DefaultConfigManagerTest {
           ConfigRepository someConfigRepository = mock(ConfigRepository.class);
           return new AbstractConfigFile(namespace, someConfigRepository) {
 
+            @Override
+            protected void update(Properties newProperties) {
+
+            }
+
             @Override
             public String getContent() {
               return someConfigContent;

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

@@ -6,8 +6,14 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.when;
 
+import com.ctrip.framework.apollo.ConfigFile;
+import com.ctrip.framework.apollo.ConfigFileChangeListener;
+import com.ctrip.framework.apollo.enums.PropertyChangeType;
+import com.ctrip.framework.apollo.model.ConfigFileChangeEvent;
+import com.google.common.util.concurrent.SettableFuture;
 import java.util.Properties;
 
+import java.util.concurrent.TimeUnit;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -84,10 +90,27 @@ public class PropertiesConfigFileTest {
     Properties anotherProperties = new Properties();
     anotherProperties.setProperty(someKey, anotherValue);
 
+    final SettableFuture<ConfigFileChangeEvent> configFileChangeFuture = SettableFuture.create();
+    ConfigFileChangeListener someListener = new ConfigFileChangeListener() {
+      @Override
+      public void onChange(ConfigFileChangeEvent changeEvent) {
+        configFileChangeFuture.set(changeEvent);
+      }
+    };
+
+    configFile.addChangeListener(someListener);
+
     configFile.onRepositoryChange(someNamespace, anotherProperties);
 
+    ConfigFileChangeEvent changeEvent = configFileChangeFuture.get(500, TimeUnit.MILLISECONDS);
+
     assertFalse(configFile.getContent().contains(String.format("%s=%s", someKey, someValue)));
     assertTrue(configFile.getContent().contains(String.format("%s=%s", someKey, anotherValue)));
+
+    assertEquals(someNamespace, changeEvent.getNamespace());
+    assertTrue(changeEvent.getOldValue().contains(String.format("%s=%s", someKey, someValue)));
+    assertTrue(changeEvent.getNewValue().contains(String.format("%s=%s", someKey, anotherValue)));
+    assertEquals(PropertyChangeType.MODIFIED, changeEvent.getChangeType());
   }
 
   @Test

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

@@ -6,8 +6,13 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.when;
 
+import com.ctrip.framework.apollo.ConfigFileChangeListener;
+import com.ctrip.framework.apollo.enums.PropertyChangeType;
+import com.ctrip.framework.apollo.model.ConfigFileChangeEvent;
+import com.google.common.util.concurrent.SettableFuture;
 import java.util.Properties;
 
+import java.util.concurrent.TimeUnit;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -85,9 +90,97 @@ public class XmlConfigFileTest {
     Properties anotherProperties = new Properties();
     anotherProperties.setProperty(key, anotherValue);
 
+    final SettableFuture<ConfigFileChangeEvent> configFileChangeFuture = SettableFuture.create();
+    ConfigFileChangeListener someListener = new ConfigFileChangeListener() {
+      @Override
+      public void onChange(ConfigFileChangeEvent changeEvent) {
+        configFileChangeFuture.set(changeEvent);
+      }
+    };
+
+    configFile.addChangeListener(someListener);
+
     configFile.onRepositoryChange(someNamespace, anotherProperties);
 
+    ConfigFileChangeEvent changeEvent = configFileChangeFuture.get(500, TimeUnit.MILLISECONDS);
+
     assertEquals(anotherValue, configFile.getContent());
+    assertEquals(someNamespace, changeEvent.getNamespace());
+    assertEquals(someValue, changeEvent.getOldValue());
+    assertEquals(anotherValue, changeEvent.getNewValue());
+    assertEquals(PropertyChangeType.MODIFIED, changeEvent.getChangeType());
+  }
+
+  @Test
+  public void testOnRepositoryChangeWithContentAdded() throws Exception {
+    Properties someProperties = new Properties();
+    String key = ConfigConsts.CONFIG_FILE_CONTENT_KEY;
+    String someValue = "someValue";
+
+    when(configRepository.getConfig()).thenReturn(someProperties);
+
+    XmlConfigFile configFile = new XmlConfigFile(someNamespace, configRepository);
+
+    assertEquals(null, configFile.getContent());
+
+    Properties anotherProperties = new Properties();
+    anotherProperties.setProperty(key, someValue);
+
+    final SettableFuture<ConfigFileChangeEvent> configFileChangeFuture = SettableFuture.create();
+    ConfigFileChangeListener someListener = new ConfigFileChangeListener() {
+      @Override
+      public void onChange(ConfigFileChangeEvent changeEvent) {
+        configFileChangeFuture.set(changeEvent);
+      }
+    };
+
+    configFile.addChangeListener(someListener);
+
+    configFile.onRepositoryChange(someNamespace, anotherProperties);
+
+    ConfigFileChangeEvent changeEvent = configFileChangeFuture.get(500, TimeUnit.MILLISECONDS);
+
+    assertEquals(someValue, configFile.getContent());
+    assertEquals(someNamespace, changeEvent.getNamespace());
+    assertEquals(null, changeEvent.getOldValue());
+    assertEquals(someValue, changeEvent.getNewValue());
+    assertEquals(PropertyChangeType.ADDED, changeEvent.getChangeType());
+  }
+
+  @Test
+  public void testOnRepositoryChangeWithContentDeleted() throws Exception {
+    Properties someProperties = new Properties();
+    String key = ConfigConsts.CONFIG_FILE_CONTENT_KEY;
+    String someValue = "someValue";
+    someProperties.setProperty(key, someValue);
+
+    when(configRepository.getConfig()).thenReturn(someProperties);
+
+    XmlConfigFile configFile = new XmlConfigFile(someNamespace, configRepository);
+
+    assertEquals(someValue, configFile.getContent());
+
+    Properties anotherProperties = new Properties();
+
+    final SettableFuture<ConfigFileChangeEvent> configFileChangeFuture = SettableFuture.create();
+    ConfigFileChangeListener someListener = new ConfigFileChangeListener() {
+      @Override
+      public void onChange(ConfigFileChangeEvent changeEvent) {
+        configFileChangeFuture.set(changeEvent);
+      }
+    };
+
+    configFile.addChangeListener(someListener);
+
+    configFile.onRepositoryChange(someNamespace, anotherProperties);
+
+    ConfigFileChangeEvent changeEvent = configFileChangeFuture.get(500, TimeUnit.MILLISECONDS);
+
+    assertEquals(null, configFile.getContent());
+    assertEquals(someNamespace, changeEvent.getNamespace());
+    assertEquals(someValue, changeEvent.getOldValue());
+    assertEquals(null, changeEvent.getNewValue());
+    assertEquals(PropertyChangeType.DELETED, changeEvent.getChangeType());
   }
 
   @Test

apollo-demo/src/main/java/com/ctrip/framework/apollo/demo/api/ApolloConfigDemo.java

@@ -5,10 +5,12 @@ import com.google.common.base.Charsets;
 import com.ctrip.framework.apollo.Config;
 import com.ctrip.framework.apollo.ConfigChangeListener;
 import com.ctrip.framework.apollo.ConfigFile;
+import com.ctrip.framework.apollo.ConfigFileChangeListener;
 import com.ctrip.framework.apollo.ConfigService;
 import com.ctrip.framework.apollo.core.enums.ConfigFileFormat;
 import com.ctrip.framework.apollo.model.ConfigChange;
 import com.ctrip.framework.apollo.model.ConfigChangeEvent;
+import com.ctrip.framework.apollo.model.ConfigFileChangeEvent;
 import com.ctrip.framework.foundation.Foundation;
 
 import org.slf4j.Logger;
@@ -48,6 +50,12 @@ public class ApolloConfigDemo {
     publicConfig.addChangeListener(changeListener);
     applicationConfigFile = ConfigService.getConfigFile("application", ConfigFileFormat.Properties);
     xmlConfigFile = ConfigService.getConfigFile("datasources", ConfigFileFormat.XML);
+    xmlConfigFile.addChangeListener(new ConfigFileChangeListener() {
+      @Override
+      public void onChange(ConfigFileChangeEvent changeEvent) {
+        logger.info(changeEvent.toString());
+      }
+    });
   }
 
   private String getConfig(String key) {