java 学习笔记（四） java连接ZooKeeper

public class Demo2 {

public static void main(String[] args) {
String connectString = "192.168.168.133:2181";
int sessionTimeout = 500000; // 会话时间。设置长一点，如果不够长，则会connect loss
try {
// 建立zookeeper链接
ZooKeeper zk = new ZooKeeper(connectString, sessionTimeout, new Watcher(){
public void process(WatchedEvent event) {
// 监控所有触发的事件
System.out.println("start do something");
EventType type = event.getType(); // 事件类型。枚举
KeeperState state = event.getState(); // 状态。 枚举
// type.getIntValue();
switch (type) { 
case None: // int值对应 -1
System.out.println("none 事件触发");
break;
case NodeCreated: // int值对应 1
System.out.println("创建节点事件发生了");
break;
case NodeDeleted: // int值对应 2
System.out.println("删除节点事件发生了");
break;
case NodeDataChanged: // int值对应 3
System.out.println("节点数据改变事件发生了");
break;
case NodeChildrenChanged: // int值对应 4
System.out.println("子节点改变事件发生了");
break;
default:
System.out.println("I do not know what operate you do");
break;
}
// state.getIntValue(); NoSyncConnected 1和Unknown-1
switch (state) {
case Disconnected: // 0
System.out.println("失去连接");
break;
case SyncConnected: // 3
System.out.println("异步链接");
break;
case Expired: // -112
System.out.println("超时过期");
break;
default:
break;
}

System.out.println("end");
}
});
System.out.println("zk创建成功");
List<String> list = zk.getChildren("/", true); // 获取所有节点
if(list != null) {
for(String s : list)
System.out.println(s);
}
// 在/app5节点下创建child节点
zk.create("/app7", "/app8的子节点数据".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); // 会对数据持久化，服务下次启动任然存在
zk.create("/app8", "/app8的子节点数据".getBytes(), Ids.OPEN_ACL_UNSAFE, 
CreateMode.PERSISTENT, new StringCallback(){
public void processResult(int rc, String path, Object ctx, String name) {
System.out.println("rc: " + rc);
System.out.println("path: " + path);
System.out.println("Object:" + ctx);
System.out.println("name: " + name);
}
}, "ctx object");

} catch (IOException e) {
e.printStackTrace();
} catch (KeeperException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

zk每一次操纵都会被监控watcher记录下来

 

出现这种报错是由于创建节点的时候没有创建父节点 /app1