Zookeeper JAVA API
/*
* ZookeeperTest.java
*/
package com.x.zookeeper;
import java.io.IOException;
import java.util.List;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author http://blog.csdn.net/java2000_wl
* @version <b>1.0</b>
*/
public class ZookeeperTest {
private static final int SESSION_TIMEOUT = 30000;
public static final Logger LOGGER = LoggerFactory.getLogger(ZookeeperTest.class);
private Watcher watcher = new Watcher() {
public void process(WatchedEvent event) {
LOGGER.info("process : " + event.getType());
}
};
private ZooKeeper zooKeeper;
/**
* 连接zookeeper
* <br>------------------------------<br>
* @throws IOException
*/
@Before
public void connect() throws IOException {
zooKeeper = new ZooKeeper("localhost:2181,localhost:2182,localhost:2183", SESSION_TIMEOUT, watcher);
}
/**
* 关闭连接
* <br>------------------------------<br>
*/
@After
public void close() {
try {
zooKeeper.close();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* 创建一个znode
* 1.CreateMode 取值
* PERSISTENT：持久化，这个目录节点存储的数据不会丢失
* PERSISTENT_SEQUENTIAL：顺序自动编号的目录节点，这种目录节点会根据当前已近存在的节点数自动加 1，然后返回给客户端已经成功创建的目录节点名；
* EPHEMERAL：临时目录节点，一旦创建这个节点的客户端与服务器端口也就是 session过期超时，这种节点会被自动删除
* EPHEMERAL_SEQUENTIAL：临时自动编号节点
* <br>------------------------------<br>
*/
@Test
public void testCreate() {
String result = null;
try {
result = zooKeeper.create("/zk001", "zk001data".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
LOGGER.info("create result : {}", result);
}
/**
* 删除节点 忽略版本
* <br>------------------------------<br>
*/
@Test
public void testDelete() {
try {
zooKeeper.delete("/zk001", -1);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
}
/**
* 获取数据
* <br>------------------------------<br>
*/
@Test
public void testGetData() {
String result = null;
try {
byte[] bytes = zooKeeper.getData("/zk001", null, null);
result = new String(bytes);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
LOGGER.info("getdata result : {}", result);
}
/**
* 获取数据 设置watch
* <br>------------------------------<br>
*/
@Test
public void testGetDataWatch() {
String result = null;
try {
byte[] bytes = zooKeeper.getData("/zk001", new Watcher() {
public void process(WatchedEvent event) {
LOGGER.info("testGetDataWatch watch : {}", event.getType());
}
}, null);
result = new String(bytes);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
LOGGER.info("getdata result : {}", result);
// 触发wacth NodeDataChanged
try {
zooKeeper.setData("/zk001", "testSetData".getBytes(), -1);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
}
/**
* 判断节点是否存在
* 设置是否监控这个目录节点，这里的 watcher 是在创建 ZooKeeper实例时指定的 watcher
* <br>------------------------------<br>
*/
@Test
public void testExists() {
Stat stat = null;
try {
stat = zooKeeper.exists("/zk001", false);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
Assert.assertNotNull(stat);
LOGGER.info("exists result : {}", stat.getCzxid());
}
/**
* 设置对应znode下的数据 , -1表示匹配所有版本
* <br>------------------------------<br>
*/
@Test
public void testSetData() {
Stat stat = null;
try {
stat = zooKeeper.setData("/zk001", "testSetData".getBytes(), -1);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
Assert.assertNotNull(stat);
LOGGER.info("exists result : {}", stat.getVersion());
}
/**
* 判断节点是否存在,
* 设置是否监控这个目录节点，这里的 watcher 是在创建 ZooKeeper实例时指定的 watcher
* <br>------------------------------<br>
*/
@Test
public void testExistsWatch1() {
Stat stat = null;
try {
stat = zooKeeper.exists("/zk001", true);
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
Assert.assertNotNull(stat);
try {
zooKeeper.delete("/zk001", -1);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 判断节点是否存在,
* 设置监控这个目录节点的 Watcher
* <br>------------------------------<br>
*/
@Test
public void testExistsWatch2() {
Stat stat = null;
try {
stat = zooKeeper.exists("/zk002", new Watcher() {
@Override
public void process(WatchedEvent event) {
LOGGER.info("testExistsWatch2 watch : {}", event.getType());
}
});
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
Assert.assertNotNull(stat);
// 触发watch 中的process方法 NodeDataChanged
try {
zooKeeper.setData("/zk002", "testExistsWatch2".getBytes(), -1);
} catch (Exception e) {
e.printStackTrace();
}
// 不会触发watch 只会触发一次
try {
zooKeeper.delete("/zk002", -1);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 获取指定节点下的子节点
* <br>------------------------------<br>
*/
@Test
public void testGetChild() {
try {
zooKeeper.create("/zk/001", "001".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
zooKeeper.create("/zk/002", "002".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
List<String> list = zooKeeper.getChildren("/zk", true);
for (String node : list) {
LOGGER.info("node {}", node);
}
} catch (Exception e) {
LOGGER.error(e.getMessage());
Assert.fail();
}
}
}