标签：for dia void 更新 lis 策略 mes 回调 mamicode
Curator n ?kyoor??āt?r: a keeper or custodian of a museum or other collection - A ZooKeeper Keeper.
Apache Curator is a Java/JVM client library for Apache ZooKeeper, a distributed coordination service. It includes a highlevel API framework and utilities to make using Apache ZooKeeper much easier and more reliable. It also includes recipes for common use cases and extensions such as service discovery and a Java 8 asynchronous DSL.
maven依赖：
<dependencies>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.10</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.6.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.6.0</version>
<exclusions>
<exclusion>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
</dependencies>
连接对象创建的代码
public static void main(String[] args) {
CuratorFramework ct = CuratorFrameworkFactory.builder()
//ip:端口
.connectString("192.168.10.132:2181,192.168.10.133:2181,192.168.10.135:2181")//连接集群
//超时时间
.sessionTimeoutMs(5000)
//连接断开5秒后，会进行一次重连
.retryPolicy(new RetryOneTime(5000))
//命名空间，该命名空间作为父节点
.namespace("ct").build();
//打开连接
ct.start();
//是否连接成功
System.out.println(ct.isStarted());
//关闭连接
ct.close();
}
重连策略：
RetryOneTime(int sleepMsBetweenRetry)：只重连一次
RetryNTimes(int n, int sleepMsBetweenRetries)：重连n次
RetryUntilElapsed(int maxElapsedTimeMs, int sleepMsBetweenRetries)：每sleepMsBetweenRetries毫秒重连一次，总等待时间超过maxElapsedTimeMs毫秒后停止重连
ExponentialBackoffRetry(int baseSleepTimeMs, int maxRetries)：重连maxRetries次，重连间隔基于baseSleepTimeMs计算
计算公式如下：baseSleepTimeMs*Math.max(1,random.nextInt(1<<(retryCount+1)))。
ct.create()
//节点类型
.withMode(CreateMode.PERSISTENT)
//节点权限
.withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)
//节点路径和数据
.forPath("/node1","node1".getBytes());
支持递归创建节点
ct.create()
//父节点不存在则创建
.creatingParentsIfNeeded()
//节点类型
.withMode(CreateMode.PERSISTENT)
//节点权限
.withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)
//节点路径和数据
.forPath("/node2/node2","node2".getBytes());
异步方式创建（删除、更新、查询省略）：
ct.create()
//父节点不存在则创建
.creatingParentsIfNeeded()
//节点类型
.withMode(CreateMode.PERSISTENT)
//节点权限
.withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)
//异步回调
.inBackground(new BackgroundCallback() {
public void processResult(CuratorFramework client, CuratorEvent event) throws Exception {
System.out.println(event.getPath()+":"+event.getType());
}
})
//节点路径和数据
.forPath("node3","node3".getBytes());
ct.setData().withVersion(-1).forPath("/node3","node33".getBytes());
ct.delete().withVersion(-1).forPath("/node3");
删除包含子节点的节点
//递归删除
ct.delete()
.deletingChildrenIfNeeded()
.withVersion(-1).forPath("/node2");
//查询
byte[] bytes = ct.getData().forPath("/node1");
System.out.println(new String(bytes));
读取属性：
Stat stat = new Stat();
byte[] bytes = ct.getData()
.storingStatIn(stat).forPath("/node1");
System.out.println(new String(bytes));
System.out.println(stat);
// /ct/node1/node2
List<String> list = ct.getChildren().forPath("/node1");
for (String s : list) {
System.out.println(s);
}
//如果节点不存在，则返回值为null
Stat stat = ct.checkExists().forPath("/node11");
标签：for dia void 更新 lis 策略 mes 回调 mamicode
原文地址：https://www.cnblogs.com/wwjj4811/p/12956935.html
