Curator 基本API

Posted 2020-10-20 INEFFABLE LAND

package bjsxt.curator.base;

import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.curator.RetryLoop;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.BackgroundCallback;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.ZooKeeper.States;
import org.apache.zookeeper.data.Stat;

public class CuratorBase {
    
    /** zookeeper地址 */
//  static final String CONNECT_ADDR = "192.168.1.171:2181,192.168.1.172:2181,192.168.1.173:2181";
    static final String CONNECT_ADDR = "115.159.41.97:2181";
    /** session超时时间 */
    static final int SESSION_OUTTIME = 5000;//ms 
    
    public static void main(String[] args) throws Exception {
        
//      RetryLoop  无限重试  一直重试不好,
        
        
        //1 重试策略：初试时间为1s 重试10次
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 10);
        //2 通过工厂创建连接
        CuratorFramework cf = CuratorFrameworkFactory.builder()
                    .connectString(CONNECT_ADDR)
                    .sessionTimeoutMs(SESSION_OUTTIME)
                    .retryPolicy(retryPolicy)
//                  .namespace("super")
                    .build();
        //3 开启连接
        cf.start();
        
//      System.out.println(States.CONNECTED);
//      System.out.println(cf.getState());
        
        // 新加、删除
        
        //4 建立节点 指定节点类型（不加withMode默认为持久类型节点）、路径、数据内容
        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c1","c1内容".getBytes());
        //5 删除节点
        cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
        
        
        // 读取、修改
        
        //创建节点
        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c1","c1内容".getBytes());
        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c2","c2内容".getBytes());
        
        //读取节点
        String ret1 = new String(cf.getData().forPath("/super/c2"));
        System.out.println(ret1);
        
        //修改节点
        cf.setData().forPath("/super/c2", "修改c2内容".getBytes());
        String ret2 = new String(cf.getData().forPath("/super/c2"));
        System.out.println(ret2);   
        
        
        // 绑定回调函数
        
        ExecutorService pool = Executors.newCachedThreadPool();
        
        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT)
        .inBackground(new BackgroundCallback() {
            @Override
            public void processResult(CuratorFramework cf, CuratorEvent ce) throws Exception {
                System.out.println("code:" + ce.getResultCode());
                System.out.println("type:" + ce.getType());
                System.out.println("线程为:" + Thread.currentThread().getName());
            }
        }, pool)
        .forPath("/super/c3","c3内容".getBytes());
        Thread.sleep(Integer.MAX_VALUE);
        
        
        
        // 读取子节点getChildren方法 和 判断节点是否存在checkExists方法
        
        List<String> list = cf.getChildren().forPath("/super");
        for(String p : list){
            System.out.println(p);
        }
        
        Stat stat = cf.checkExists().forPath("/super/c3");
        System.out.println(stat);
        
        Thread.sleep(2000);
        cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
        
        
        
        //cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
        
    }
}