作者：雨中散步撒哈拉
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环境阐明:
- 服务器为centos7集群
- zk为zookeeper-3.4.10.tar.gz版本
- jdk为1.8
一、创立我的项目
1. 增加依赖包，pom文件如下
<dependencies><dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>RELEASE</version></dependency><dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.8.2</version></dependency><!--https://mvnrepository.com/artifact/org.apache.zookeeper/zookeeper --><dependency> <groupId>org.apache.zookeeper</groupId> <artifactId>zookeeper</artifactId> <version>3.4.10</version></dependency></dependencies>2. 配置日志文件
资源文件创建日志配置文件log4j.properties
log4j.rootLogger=INFO, stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n log4j.appender.logfile=org.apache.log4j.FileAppender log4j.appender.logfile.File=target/spring.loglog4j.appender.logfile.layout=org.apache.log4j.PatternLayout log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n二、代码实现zk命令
0. 创立连贯
连贯集群ip和对外端口2181，集群映射，已在windows做了配置
hosts文件内容：
代码实现连贯:
private static final String IPS = "master:2181,slave1:2181,slave2:2181";private static final int SESSIONTIMEOUT = 200;private ZooKeeper zkClient = null;@Testpublic void contectTest() throws Exception{ zkClient = new ZooKeeper(IPS, SESSIONTIMEOUT, new Watcher() { @Override public void process(WatchedEvent event) { } }); System.out.println("=================="); System.out.println(zkClient.getState()); System.out.println("==================");}运行打印后果
image.png
2. 创立节点
创立/idea节点，类型为长期节点
private static final String IPS = "master:2181,slave1:2181,slave2:2181";private static final int SESSIONTIMEOUT = 200;private ZooKeeper zkClient = null;@Beforepublic void contectTest() throws Exception{ zkClient = new ZooKeeper(IPS, SESSIONTIMEOUT, new Watcher() { @Override public void process(WatchedEvent event) { } }); System.out.println("=================="); System.out.println(zkClient.getState()); System.out.println("==================");}@Testpublic void createTest() throws Exception{ String s = zkClient.create("/idea", "helloworld".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL); System.out.println(s);}打印后果
image.png
3. 监听节点变动
监控根节点下的子节点变动
private static final String IPS = "master:2181,slave1:2181,slave2:2181";private static final int SESSIONTIMEOUT = 200;private ZooKeeper zkClient = null;@Beforepublic void contectTest() throws Exception{ zkClient = new ZooKeeper(IPS, SESSIONTIMEOUT, new Watcher() { @Override public void process(WatchedEvent event) { System.out.println(event.getType() + "--" + event.getPath()); try { zkClient.getChildren("/", true); } catch (KeeperException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } }); System.out.println("=================="); System.out.println(zkClient.getState()); System.out.println("==================");}@Testpublic void childrenTest() throws Exception{ List<String> children = zkClient.getChildren("/", true); for (String ch : children){ System.out.println(ch); } Thread.sleep(Long.MAX_VALUE);}在xshell典范增加节点，也能够在代码中模拟增加节点
[zk: localhost:2181(CONNECTED) 0] create -e /java "java"Created /java[zk: localhost:2181(CONNECTED) 1] create -e /python "java"Created /python打印后果
image.png
4. 判断节点是否存在
private static final String IPS = "master:2181,slave1:2181,slave2:2181";private static final int SESSIONTIMEOUT = 200;private ZooKeeper zkClient = null;@Beforepublic void contectTest() throws Exception{ zkClient = new ZooKeeper(IPS, SESSIONTIMEOUT, new Watcher() { @Override public void process(WatchedEvent event) { } }); System.out.println("=================="); System.out.println(zkClient.getState()); System.out.println("==================");}@Testpublic void exTest() throws Exception{ Stat exists = zkClient.exists("/test", false); System.out.println(exists == null ? "no" : "yes");}打印后果
image.png
5. 测试残缺代码
package com.example.demo;import org.apache.zookeeper.*;import org.apache.zookeeper.data.Stat;import org.junit.Before;import org.junit.Test;import java.util.List;public class ZKDemo { private static final String IPS = "master:2181,slave1:2181,slave2:2181"; private static final int SESSIONTIMEOUT = 200; private ZooKeeper zkClient = null; @Before public void contectTest() throws Exception{ zkClient = new ZooKeeper(IPS, SESSIONTIMEOUT, new Watcher() { @Override public void process(WatchedEvent event) { /*System.out.println(event.getType() + "--" + event.getPath()); try { zkClient.getChildren("/", true); } catch (KeeperException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); }*/ } }); System.out.println("=================="); System.out.println(zkClient.getState()); System.out.println("=================="); } @Test public void createTest() throws Exception{ String s = zkClient.create("/idea", "helloworld".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL); System.out.println(s); } @Test public void childrenTest() throws Exception{ List<String> children = zkClient.getChildren("/", true); for (String ch : children){ System.out.println(ch); } Thread.sleep(Long.MAX_VALUE); } @Test public void exTest() throws Exception{ Stat exists = zkClient.exists("/test", false); System.out.println(exists == null ? "no" : "yes"); }}文末福利
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