ZooKeeper(二) idea中使用Java操作zookeeper
本章介绍使在idea环境中使用maven工程进行连接zookeeper，并进行简单的增删查改操作。
一、使用的pom依赖
添加zookeeper依赖，以及进行测试的junit测试依赖。
4.0.0
com.xiaohui.zk
zkdemo1
1.0-SNAPSHOT
org.apache.zookeeper
zookeeper
3.4.7
junit
junit
4.12
二、添加测试类进行连接、新增、修改、查询等操作
1，进行连接zookeeper，并进行创建一个 /huizi 节点
在创建时参数 ZooDefs.Ids.OPEN_ACL_UNSAFE 表示节点的访问权限，OPEN_ACL_UNSAFE 表示可以被所有的客户端节点访问到。
public class FirstTest {
@Test
public void test() throws Exception {
//1, 创建zk连接
ZooKeeper zooKeeper = new ZooKeeper("172.18.255.118:2181", 2000, new Watcher() {
public void process(WatchedEvent watchedEvent) {
System.out.println("收到监听：type:"+watchedEvent.getType()+", Path:"+watchedEvent.getPath()+", State:"+watchedEvent.getState());
}
});
//2，创建父节点
String path = zooKeeper.create("/huizi",
"nodeValue".getBytes(),
ZooDefs.Ids.OPEN_ACL_UNSAFE, //
CreateMode.PERSISTENT);//四种模式
System.out.println("路径："+path);
}
}执行结束后可以通过linux客户端工具在安装目录bin下使用 ./zkCli.sh 进入客户端命令控制台 命令 ls / 查看成功创建节点 huizi 。
2，创建子节点代码
package com.xiaohui.zk.test;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;
import org.junit.Test;
import java.io.IOException;
import java.util.List;
public class FirstTest {
@Test
public void test() throws Exception {
//1, 创建zk连接
ZooKeeper zooKeeper = new ZooKeeper("172.18.255.118:2181", 2000, new Watcher() {
public void process(WatchedEvent watchedEvent) {
System.out.println("收到监听：type:"+watchedEvent.getType()+", Path:"+watchedEvent.getPath()+", State:"+watchedEvent.getState());
}
});
//2，创建父节点
// String path = zooKeeper.create("/huizi",
// "nodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("路径："+path);
//3, 创建子节点
String childenPath = zooKeeper.create("/huizi/childenNode",
"childenNodeValue".getBytes(),
ZooDefs.Ids.OPEN_ACL_UNSAFE, //
CreateMode.PERSISTENT);//四种模式
System.out.println("childenPath路径："+childenPath);
}
}控制台使用 ls /huizi 查看其下面的子节点：
3，打印父节点和子节点中的值
package com.xiaohui.zk.test;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;
import org.junit.Test;
import java.io.IOException;
import java.util.List;
public class FirstTest {
@Test
public void test() throws Exception {
//1, 创建zk连接
ZooKeeper zooKeeper = new ZooKeeper("172.18.255.118:2181", 2000, new Watcher() {
public void process(WatchedEvent watchedEvent) {
System.out.println("收到监听：type:"+watchedEvent.getType()+", Path:"+watchedEvent.getPath()+", State:"+watchedEvent.getState());
}
});
//2，创建父节点
// String path = zooKeeper.create("/huizi",
// "nodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("路径："+path);
//3, 创建子节点
// String childenPath = zooKeeper.create("/huizi/childenNode",
// "childenNodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("childenPath路径："+childenPath);
//4, 获取节点中的值（父节点和子节点）
byte[] value = zooKeeper.getData("/huizi",false,null);
System.out.println("p:"+new String(value));
List children = zooKeeper.getChildren("/huizi", false);
for (String child : children) {
System.out.println("c:"+child);
}
}
}
打印如下：
收到监听：type:None, Path:null, State:SyncConnected
p:nodeValue
c:childenNode4，修改节点中的值
在set 方法中 最后一个参数 表示版本号，-1 表示可以被所有版本都可以匹配到。
package com.xiaohui.zk.test;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;
import org.junit.Test;
import java.io.IOException;
import java.util.List;
public class FirstTest {
@Test
public void test() throws Exception {
//1, 创建zk连接
ZooKeeper zooKeeper = new ZooKeeper("172.18.255.118:2181", 2000, new Watcher() {
public void process(WatchedEvent watchedEvent) {
System.out.println("收到监听：type:"+watchedEvent.getType()+", Path:"+watchedEvent.getPath()+", State:"+watchedEvent.getState());
}
});
//2，创建父节点
// String path = zooKeeper.create("/huizi",
// "nodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("路径："+path);
//3, 创建子节点
// String childenPath = zooKeeper.create("/huizi/childenNode",
// "childenNodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("childenPath路径："+childenPath);
//4, 获取节点中的值（父节点和子节点）
// byte[] value = zooKeeper.getData("/huizi",false,null);
// System.out.println("p:"+new String(value));
//
// List children = zooKeeper.getChildren("/huizi", false);
// for (String child : children) {
// System.out.println("c:"+child);
// }
//5, 修改节点的值
zooKeeper.setData("/huizi", "newValue".getBytes(), -1);
byte[] value = zooKeeper.getData("/huizi",false,null);
System.out.println("data:"+new String(value));
}
} 5，删除某个节点，并查看其是否存在
package com.xiaohui.zk.test;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;
import org.junit.Test;
import java.io.IOException;
import java.util.List;
public class FirstTest {
@Test
public void test() throws Exception {
//1, 创建zk连接
ZooKeeper zooKeeper = new ZooKeeper("172.18.255.118:2181", 2000, new Watcher() {
public void process(WatchedEvent watchedEvent) {
System.out.println("收到监听：type:"+watchedEvent.getType()+", Path:"+watchedEvent.getPath()+", State:"+watchedEvent.getState());
}
});
//2，创建父节点
// String path = zooKeeper.create("/huizi",
// "nodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("路径："+path);
//3, 创建子节点
// String childenPath = zooKeeper.create("/huizi/childenNode",
// "childenNodeValue".getBytes(),
// ZooDefs.Ids.OPEN_ACL_UNSAFE, //
// CreateMode.PERSISTENT);//四种模式
// System.out.println("childenPath路径："+childenPath);
//4, 获取节点中的值（父节点和子节点）
// byte[] value = zooKeeper.getData("/huizi",false,null);
// System.out.println("p:"+new String(value));
//
// List children = zooKeeper.getChildren("/huizi", false);
// for (String child : children) {
// System.out.println("c:"+child);
// }
//5, 修改节点的值
// zooKeeper.setData("/huizi", "newValue".getBytes(), -1);
// byte[] value = zooKeeper.getData("/huizi",false,null);
// System.out.println("data:"+new String(value));
//6, 判断某个节点是否存在
Stat exists = zooKeeper.exists("/huizi/childenNode", false);
System.out.println(exists);
//7, 删除节点
zooKeeper.delete("/huizi/childenNode", -1);
Stat exists1 = zooKeeper.exists("/huizi/childenNode", false);
System.out.println(exists1);
}
}
打印如下：
收到监听：type:None, Path:null, State:SyncConnected
4294967326,4294967326,1596599387683,1596599387683,0,0,0,0,16,0,4294967326
null