ERROR org.apache.zookeeper.ClientCnxn:532 - Error while calling watcher

一、背景

使用zookeeper操作时提示这个错误信息

ERROR org.apache.zookeeper.ClientCnxn: - Error while calling watcher

java.lang.NullPointerException
  at org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:530)
  at org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:505)

但是检查zookeeper服务器上实际的操作却是成功了。

二、抛出位置

zk = new ZooKeeper(url, , null);

三、解决方法

zk = new ZooKeeper(url, , new Watcher(){
    @Override
    public void process(WatchedEvent event) {
        // TODO Auto-generated method stub
        logger.debug(" receive event : "+event.getType().name());
    }
});