zookeeper API 基础

旧城等待， 2022-12-28 06:59 148阅读 0赞

package com.zookeeper;
    
    import org.apache.zookeeper.*;
    import org.apache.zookeeper.data.Stat;
    import org.junit.Before;
    import org.junit.Test;
    
    import java.util.List;
    
    /** * @version v1.0 * @Author: huang* * @Date: 2020/12/11* */
    public class ZookeeperDemo { 
        private static String connectString = "bigdata01:2181,bigdata02:2181,bigdata03:2181";
        private static int sessionTimeout = 2000;
        private ZooKeeper zkClient = null;
    
        @Before
        public void init() throws Exception { 
            zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() { 
                @Override
                public void process(WatchedEvent watchedEvent) { 
    
                    System.out.println(watchedEvent.getType() + "--" + watchedEvent.getPath());
                    System.out.println("连接成功");
                    try { 
                        zkClient.getChildren("/", true);
                    } catch (Exception e) { 
                        e.printStackTrace();
                    }
                }
            });
    
    
        }
    //创建节点
        @Test
        public void create() throws  Exception{ 
            String nodeCreated = zkClient.create("/huang", "lan".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            System.out.println(nodeCreated);
        }
    
        // 判断znode是否存在
        @Test
        public void exist() throws Exception { 
    
            Stat stat = zkClient.exists("/atguigu1", false);
    
            System.out.println(stat == null ? "not exist" : "exist");
        }
    //设置节点数据
    @Test
        public  void setData() throws Exception{ 
    
              zkClient.setData("/atguigu1","jinlian1".getBytes(),0);
    }
    
     @Test
     //获取节点
        public  void getDate() throws Exception{ 
         byte[] zkClientData = zkClient.getData("/atguigu1", null, null
         );
         System.out.println(zkClientData);
     }
    
        @Test
        public void delete() throws KeeperException, InterruptedException { 
            zkClient.delete("/atguigu/a1", 1);
    
        }
    
    
        @Test
        // 获取指定路径下的所有节点，包括子节点
        public void lsAll() throws Exception { 
            ls("/");
        }
        public void ls(String path) throws Exception { 
            List<String> list = zkClient.getChildren(path, null);
            if (list == null || list.isEmpty()) { 
                return;
            }
            for (String s : list) { 
                if (path.equals("/")) { 
                    ls(path + s);
                } else { 
                    ls(path + "/" + s);
                }
            }
        }
    
    
        @Test
        public void watchChange1() throws Exception { 
            Stat stat = new Stat();
            byte[] data = zkClient.getData("/atguigu", new Watcher() { 
                @Override
                public void process(WatchedEvent event) { 
                    if (event.getType() == Event.EventType.NodeDataChanged) { 
                        System.out.println("节点数据改变了！");
                    }
                }
            }, stat);
            System.out.println(new String(data));
            Thread.sleep(50000);
        }
    
        //zookeeper中的监听默认是一次性的。要想永久监听需要自己处理：
        @Test
        public void watchChange2() throws Exception { 
            final Stat stat = new Stat();
    
            final String path = "/atguigu";
            byte[] data = zkClient.getData(path, new Watcher() { 
                @Override
                public void process(WatchedEvent event) { 
                    if (event.getType() == Event.EventType.NodeDataChanged) { 
                        try { 
    
                            byte[] res = zkClient.getData(path, this,stat);//设置可以反复监听
                            System.out.println("节点数据改变了 " + new String(res));
                        } catch (KeeperException | InterruptedException e) { 
                            e.printStackTrace();
                        }
                    }
                }
            }, stat);
            System.out.println(new String(data));
            Thread.sleep(50000);
        }
    
        //获取节点并监听节点删除
    
        @Test
        public void watchDelete() throws Exception { 
            String path = "/atuguigu/a3";
            Stat stat = new Stat();
    
    
            byte[] data = zkClient.getData(path, new Watcher() { 
                @Override
                public void process(WatchedEvent event) { 
                    if (event.getType() == Event.EventType.NodeDeleted) { 
                        System.out.println("节点数据删除了！");
                    }
                }
            }, stat);
    
            System.out.println("****" + new String(data));
    
            // 延时阻塞
            Thread.sleep(Long.MAX_VALUE);
        }
    
    
    
    }