客户端 API
PPG007 ... 2021-12-28 Less than 1 minute
# 客户端 API
# 导入依赖
<!-- https://mvnrepository.com/artifact/org.apache.zookeeper/zookeeper -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.7.0</version>
</dependency>
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# 创建节点
远程服务器超时时间要设置的久一些：
public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
int timeOut=200000;
String connectStr="150.158.153.216:2181,39.107.112.172:2181,115.28.211.227:2181";//使用逗号分隔，不能带空格
ZooKeeper zooKeeper = new ZooKeeper(connectStr, timeOut, watchedEvent -> System.out.println(watchedEvent.getState()));
String s = zooKeeper.create("/sanguo", "sanguo".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
}
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# 监听节点变化
创建监听方法，此方法阻塞：
@org.junit.Test
public void getChildren() throws IOException, InterruptedException, KeeperException {
zooKeeper.getChildren("/",true);//第二个参数为true表示使用创建zookeeper时定义的监听器
System.in.read();
}
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循环注册，循环监听：
@Before
public void init() throws IOException {
int timeOut=200000;
String connectStr="150.158.153.216:2181,39.107.112.172:2181,115.28.211.227:2181";
zooKeeper = new ZooKeeper(connectStr, timeOut, watchedEvent -> {
List<String> children = null;
try {
children = zooKeeper.getChildren("/", true);
} catch (KeeperException | InterruptedException e) {
e.printStackTrace();
}
assert children != null;
for (String child : children) {
System.out.println(child);
}
});
}
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# 判断节点是否存在
@org.junit.Test
public void exist() throws InterruptedException, KeeperException {
Stat exists = zooKeeper.exists("/sanguo", false);
if (exists == null) {
System.out.println("节点：[/sanguo] 不存在");
}else {
System.out.println("节点：[/sanguo] 存在");
}
}
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