java操作zookeeper
- 创建一个maven项目在pom文件里引入如下依赖：
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<scope>test</scope>
</dependency>
<!-- curator-->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>4.0.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>4.0.0</version>
</dependency>
<!-- 日志 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.21</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.21</version>
</dependency>
</dependencies>
- 创建一个测试类进行相关操作的测试
@Before
public void testConnect(){
ExponentialBackoffRetry retryPolicy = new ExponentialBackoffRetry(3000, 10);
client = CuratorFrameworkFactory.builder() // 使用工厂类来建造客户端的实例对象
.connectString("192.168.223.131:2181") // 指定连接zookeeper的服务器地址
.retryPolicy(retryPolicy) // 指定重试策略
.namespace("test") // 指定命名空间
.build(); // 建造客户端实例对象
client.start(); // 启动客户端
}
@After
public void testClose(){
// 关闭客户端
if (client != null){
client.close();
}
}
@Test
public void testCreateNode() throws Exception {
// 如果没有指定命名空间，那么节点的完整路径为 /node2，如果指定了命名空间，那么节点的完整路径为 /test/node2
// 如果没有数据，那么节点的数据为当前客户端的ip地址
// 如果没有指定节点类型，那么节点类型为持久节点
// CreateMode.EPHEMERAL 临时节点
// creatingParentsIfNeeded() 如果父节点不存在，那么自动创建父节点
String path = client.create()
.creatingParentsIfNeeded()
.withMode(CreateMode.EPHEMERAL)
.forPath("/node3/min", "node3min".getBytes());
System.out.println(path);
// 让线程阻塞，不让程序结束，这样可以在zookeeper中看到创建的临时节点，因为临时节点的生命周期是和客户端绑定的
Thread.sleep(100000);
}
@Test
public void testGetData() throws Exception {
byte[] bytes = client.getData().forPath("/node2");
System.out.println(new String(bytes));
}
@Test
public void testGetChildren() throws Exception {
List<String> childrenList = client.getChildren().forPath("/");
for (String child : childrenList) {
System.out.println(child);
}
}
@Test
public void testGetStat() throws Exception {
// Stat类用于存储节点状态信息
Stat stat = new Stat();
// storingStatIn(stat) 将节点状态信息存储到stat对象中
byte[] data = client.getData().storingStatIn(stat).forPath("/node2");
System.out.println(new String(data));
System.out.println(stat);
}
@Test
public void testSetData() throws Exception {
client.setData().forPath("/node2/min1", "minqiliang".getBytes());
}
@Test
public void testSetDataWithVersion() throws Exception {
Stat stat = new Stat();
client.getData().storingStatIn(stat).forPath("/node3");
System.out.println(stat.getVersion());
client.setData().withVersion(stat.getVersion()).forPath("/node3", "minqiliang".getBytes());
}
@Test
public void testDeleteNode() throws Exception {
// deletingChildrenIfNeeded() 如果存在子节点，那么先删除子节点，再删除父节点
client.delete().deletingChildrenIfNeeded().forPath("/node2");
}
@Test
public void testDeleteNodeWithVersion() throws Exception {
// guaranteed() 如果删除失败，那么会在后台一直尝试删除，直到删除成功为止
client.delete().guaranteed().forPath("/node3");
}
@Test
public void testDeleteNodeWithCallback() throws Exception {
// inBackground() 指定回调函数
client.delete().guaranteed().inBackground((client, event) -> System.out.println(event)).forPath("/node3");
Thread.sleep(100000);
}
@Test
public void testNodeCache() throws Exception {
// 创建一个nodeCache对象
NodeCache nodeCache = new NodeCache(client, "/node3");
// 注册监听器
nodeCache.getListenable().addListener(() -> {
System.out.println("节点数据发生变化");
byte[] bytes = nodeCache.getCurrentData().getData();
System.out.println(new String(bytes));
});
// 启动监听器
nodeCache.start(true);
while (true){
}
}
@Test
public void testpathChildrenCache() throws Exception {
// 创建一个nodeCache对象
PathChildrenCache pathChildrenCache = new PathChildrenCache(client, "/node3",true);
// 注册监听器
pathChildrenCache.getListenable().addListener((client,event) -> {
System.out.println("节点数据发生变化");
System.out.println(event);
PathChildrenCacheEvent.Type type = event.getType();
if (type.equals(PathChildrenCacheEvent.Type.CHILD_UPDATED)){
System.out.println("子节点数据发生变化");
byte[] data = event.getData().getData();
System.out.println(new String(data));
}
});
// 启动监听器
pathChildrenCache.start(true);
while (true){
}
}
@Test
public void testTreeCache() throws Exception {
// 创建一个nodeCache对象
TreeCache treeCache = new TreeCache(client, "/node3");
// 注册监听器
treeCache.getListenable().addListener((client,event) -> {
System.out.println("节点数据发生变化");
System.out.println(event);
TreeCacheEvent.Type type = event.getType();
if (type.equals(TreeCacheEvent.Type.NODE_UPDATED)){
System.out.println("子节点数据发生变化");
byte[] data = event.getData().getData();
System.out.println(new String(data));
}
});
// 启动监听器
treeCache.start();
while (true){
}
}
- 分布式锁
InterProcessMutex lock = new InterProcessMutex(client, "/lock");
// 获取锁
try {
// 获取锁
boolean acquire = lock.acquire(3, TimeUnit.SECONDS);
}catch (Exception e) {
e.printStackTrace();
}finally {
// 释放锁
try {
lock.release();
} catch (Exception e) {
e.printStackTrace();
}
}
