Java Code Examples for org.apache.zookeeper.Watcher.Event.EventType#NodeCreated

private void processDataOrChildChange(WatchedEvent event) {
    final String path = event.getPath();

    if (event.getType() == EventType.NodeChildrenChanged || event.getType() == EventType.NodeCreated || event.getType() == EventType.NodeDeleted) {
        Set<IZkChildListener> childListeners = _childListener.get(path);
        if (childListeners != null && !childListeners.isEmpty()) {
            fireChildChangedEvents(path, childListeners);
        }
    }

    if (event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated) {
        Set<IZkDataListener> listeners = _dataListener.get(path);
        if (listeners != null && !listeners.isEmpty()) {
            fireDataChangedEvents(event.getPath(), listeners);
        }
    }
}
 

private void processDataOrChildChange(WatchedEvent event) {
    final String path = event.getPath();

    if (event.getType() == EventType.NodeChildrenChanged || event.getType() == EventType.NodeCreated || event.getType() == EventType.NodeDeleted) {
        Set<IZkChildListener> childListeners = _childListener.get(path);
        if (childListeners != null && !childListeners.isEmpty()) {
            fireChildChangedEvents(path, childListeners);
        }
    }

    if (event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated) {
        Set<IZkDataListener> listeners = _dataListener.get(path);
        if (listeners != null && !listeners.isEmpty()) {
            fireDataChangedEvents(event.getPath(), listeners);
        }
    }
}
 

private void processDataOrChildChange(WatchedEvent event) {
    final String path = event.getPath();

    if (event.getType() == EventType.NodeChildrenChanged || event.getType() == EventType.NodeCreated || event.getType() == EventType.NodeDeleted) {
        Set<IZkChildListener> childListeners = _childListener.get(path);
        if (childListeners != null && !childListeners.isEmpty()) {
            fireChildChangedEvents(path, childListeners);
        }
    }

    if (event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated) {
        Set<IZkDataListener> listeners = _dataListener.get(path);
        if (listeners != null && !listeners.isEmpty()) {
            fireDataChangedEvents(event.getPath(), listeners);
        }
    }
}
 

@Override
public void handle(String path, EventType eventType, Object data) throws Exception {
    //子节点个数变化
    if (eventType == EventType.NodeChildrenChanged 
            || eventType == EventType.NodeCreated 
            || eventType == EventType.NodeDeleted) {
        handleChildCountChanged(path,(List<String>)data);
    }
    //子节点数据变化
    if(eventType == EventType.NodeDataChanged){
        handleChildDataChanged(path,data);
    }
    //Session失效
    if(eventType == eventType.None){
        handleSessionExpired(path,data);
    }
}
 

@Override
public void handle(String path, EventType eventType, Object data) throws Exception {
    
    if (eventType == EventType.NodeCreated) {
        handleDataCreated(path,data);
    }
    
    if (eventType == EventType.NodeDataChanged) {
        handleDataChanged(path,data);
    }
    
    if(eventType == EventType.NodeDeleted ){
        handleDataDeleted(path);
    }
    
    if(eventType == eventType.None){
        handleSessionExpired(path);
    }
}
 

private void processDataOrChildChange(WatchedEvent event, long notificationTime) {
  final String path = event.getPath();
  final boolean pathExists = event.getType() != EventType.NodeDeleted;
  if (EventType.NodeDeleted == event.getType()) {
    LOG.debug("Event NodeDeleted: {}", event.getPath());
  }

  if (event.getType() == EventType.NodeChildrenChanged || event.getType() == EventType.NodeCreated
      || event.getType() == EventType.NodeDeleted) {
    Set<IZkChildListener> childListeners = _childListener.get(path);
    if (childListeners != null && !childListeners.isEmpty()) {
      // TODO recording child changed event propagation latency as well. Note this change will
      // introduce additional ZK access.
      fireChildChangedEvents(path, childListeners, pathExists);
    }
  }

  if (event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted
      || event.getType() == EventType.NodeCreated) {
    Set<IZkDataListenerEntry> listeners = _dataListener.get(path);
    if (listeners != null && !listeners.isEmpty()) {
      fireDataChangedEvents(event.getPath(), listeners, OptionalLong.of(notificationTime),
          pathExists);
    }
  }
}
 

@Test
public void testProcess3() {
    WatchedEvent event = new WatchedEvent(EventType.NodeCreated, KeeperState.Expired, null);
    sessionWatcher.process(event);
    assertFalse(sessionWatcher.isShutdownStarted());
    assertEquals(shutdownService.getExitCode(), 0);
}
 

void handleNewSessionAsController() {
  if (_leaderElectionHandler != null) {
    _leaderElectionHandler.init();
  } else {
    _leaderElectionHandler =
        new CallbackHandler(this, _zkclient, _keyBuilder.controller(),
            new DistributedLeaderElection(this, _controller, _controllerTimerTasks),
            new EventType[] {
                EventType.NodeChildrenChanged, EventType.NodeDeleted, EventType.NodeCreated
            }, ChangeType.CONTROLLER, _callbackMonitors.get(ChangeType.CONTROLLER));
  }
}
 

@Override
public void process(WatchedEvent event) {
    LOG.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated
            || event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        LOG.debug("Leaving process event");
    }
}
 

@Override
public void process(WatchedEvent event) {
    LOG.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated
            || event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        LOG.debug("Leaving process event");
    }
}
 

public void process(WatchedEvent event) {
    logger.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || //
                    event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated || //
                    event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            logger.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        logger.debug("Leaving process event");
    }
}
 

/**
 * 事件处理
 * @see org.apache.zookeeper.Watcher#process(org.apache.zookeeper.WatchedEvent)
 */
@Override
public void process(WatchedEvent event) {
    LOG.debug("ZooKeeper event is arrived [" + event+" ]...");
    EventType eventType = event.getType();
    //状态更新
    boolean stateChanged = event.getPath() == null;
    //节点相关的所有事件
    boolean znodeChanged = event.getPath() != null;
    
    //节点创建、删除和数据改变的事件
    boolean nodeChanged = eventType == EventType.NodeDataChanged 
            || eventType == EventType.NodeDeleted 
            || eventType == EventType.NodeCreated;
    
    //子节点数量改变相关的事件，包括节点创建和删除（都会影响子节点数量的变化），以及子节点数量的改变
    boolean childChanged = eventType == EventType.NodeDeleted 
            || eventType == EventType.NodeCreated
            || eventType == EventType.NodeChildrenChanged;
    
    client.acquireEventLock();
    try {
        if (client.getShutdownTrigger()) {
            LOG.debug("client will shutdown,ignore the event [" + eventType + " | " + event.getPath() + "]");
            return;
        }
        if (stateChanged) {//ZooKeeper状态改变的处理
            process.processStateChanged(event);
        }
        if (nodeChanged) {//节点改变事件处理，包括节点的创建、删除、数据改变
            process.processNodeChanged(event);
        }
        if (childChanged) {//造成子节点数量改变的事件的处理，包括节点的创建、删除、子节点数量改变
            process.processChildChanged(event);
        }
    } finally {
        if (stateChanged) {
            client.getEventLock().getStateChangedCondition().signalAll();
            // 在会话失效后，服务端会取消watch.
            // 如果在会话失效后与重连这段时间内有数据发生变化，监听器是无法监听到的，
            // 所以要唤醒等待的监听，并触发所有的监听事件
            if (event.getState() == KeeperState.Expired) {
                client.getEventLock().getNodeEventCondition().signalAll();
                client.getEventLock().getNodeOrChildChangedCondition().signalAll();
                
                // 通知所有的监听器，可能存在数据变化
                process.processAllNodeAndChildListeners(event);
            }
        }
        if (znodeChanged) {
            client.getEventLock().getNodeEventCondition().signalAll();
        }
        if (nodeChanged || childChanged) {
            client.getEventLock().getNodeOrChildChangedCondition().signalAll();
        }
        client.releaseEventLock();
    }
}
 

/**
 * 提交节点改变相关的事件进行处理
 * @param listeners
 * @param childDataChangeListners
 * @param path
 * @param eventType 
 * @return void
 */
private void submitNodeEvent(final Set<ZKListener> listeners,final Set<ZKListener> childDataChangeListners,final String path,final EventType eventType ){
    if (listeners != null && !listeners.isEmpty()) {
        for (final ZKListener listener : listeners) {
            ZKEvent zkEvent = new ZKEvent("Node of " + path + " changed sent to " + listener) {
                @Override
                public void run() throws Exception {
                    //原生的zookeeper 的监听只生效一次，重新注册监听
                    LOG.debug("Rewatch the path ["+path+"] by exists method");
                    boolean flag = client.exists(path, true);
                    LOG.debug("Rewatched the path ["+path+"] by exists method");
                    try {
                        LOG.debug("Rewatch and get changed data [path:"+path+" | EventType:"+eventType+"] by getData method");
                        Object data = client.getData(path, null);
                        LOG.debug("Rewatched and return data   ["+path+" | "+data+" | EventType:"+eventType+"] by getData method");
                        listener.handle(path, eventType, data);
                        
                        //响应了删除事件，但是在再次注册监听之前节点又被创建了，这样是无法重新监听到节点创建的
                        //这里主动触发节点创建事件。
                        if (eventType == EventType.NodeDeleted && flag) {
                            listener.handle(path, EventType.NodeCreated, data);
                        }
                    } catch (ZKNoNodeException e) {
                        //如果是节点不存在了，则只移除，ZKChildDataListener监听器
                        client.unlistenNodeChanges(path, childDataChangeListners);
                        //如果路径不存在，在调用client.getData(path,null)会抛出异常
                        listener.handle(path, eventType, null);
                        
                        //如果是创建节点事件，并且在创建事件收到后，监听还没来得及重新注册，刚创建的节点已经被删除了。
                        //对于这种情况，客户端就无法重新监听到节点的删除事件的，这里做特殊处理
                        //主动触发删除的监听事件
                        if (eventType == EventType.NodeCreated && !flag) {
                            listener.handle(path, EventType.NodeDeleted, null);
                        }
                    }
                }
            };
            eventThreadPool.submit(zkEvent);
        }
    }
    
}
 

@Override
public void process(WatchedEvent event) {
  long notificationTime = System.currentTimeMillis();
  if (LOG.isDebugEnabled()) {
    LOG.debug("Received event: " + event);
  }
  _zookeeperEventThread = Thread.currentThread();

  boolean stateChanged = event.getPath() == null;
  boolean sessionExpired = stateChanged && event.getState() == KeeperState.Expired;
  boolean znodeChanged = event.getPath() != null;
  boolean dataChanged =
      event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted
          || event.getType() == EventType.NodeCreated
          || event.getType() == EventType.NodeChildrenChanged;
  if (event.getType() == EventType.NodeDeleted) {
    LOG.debug("Path {} is deleted", event.getPath());
  }

  getEventLock().lock();
  try {
    // We might have to install child change event listener if a new node was created
    if (getShutdownTrigger()) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath()
            + "}' since shutdown triggered");
      }
      return;
    }
    if (stateChanged) {
      processStateChanged(event);
    }
    if (dataChanged) {
      processDataOrChildChange(event, notificationTime);
    }
  } finally {
    if (stateChanged) {
      getEventLock().getStateChangedCondition().signalAll();

      // If the session expired we have to signal all conditions, because watches might have been
      // removed and
      // there is no guarantee that those
      // conditions will be signaled at all after an Expired event
      // TODO PVo write a test for this
      if (event.getState() == KeeperState.Expired) {
        getEventLock().getZNodeEventCondition().signalAll();
        getEventLock().getDataChangedCondition().signalAll();
      }
    }
    if (znodeChanged) {
      getEventLock().getZNodeEventCondition().signalAll();
    }
    if (dataChanged) {
      getEventLock().getDataChangedCondition().signalAll();
    }
    getEventLock().unlock();

    // update state change counter.
    recordStateChange(stateChanged, dataChanged, sessionExpired);

    if (LOG.isDebugEnabled()) {
      LOG.debug("Leaving process event");
    }
  }
}