读取zookeeper上的dubbo注册信息

dubbo有本身的服务监听服务器，incubator-dubbo-ops-develop，github能够下载到，网上也有不少本地部署的例子，就想了下能不能本身监听dubbo的服务，因而写了以下代码。特别注意的是zookeeper的watch机制是一次性触发，当监听到该节点的事件被触发执行了一次watch以后，后面zk该节点的数据须要再次设置watch。如下代码只是提高对zk节点变化的了解，第三方的zk客户端有例如Curator,它是Netflix公司开源的一个Zookeeper客户端,与Zookeeper提供的原生客户端相比,Curator的抽象层次更高,简化了Zookeeper客户端的开发量。 还有一个101tec zkclient。curator提供的功能更丰富，zkclient功能相对简单，参考文档不如curator。

public class NesttyMain implements Watcher, AsyncCallback.StatCallback {
    private static ZooKeeper zooKeeper;
    private static Stat stat = new Stat();
    private static NesttyMain nestty = new NesttyMain();
    public static void main(String[] args) throws InterruptedException, IOException, KeeperException {
        zooKeeper = new ZooKeeper("127.0.0.1:2181", 5000, nestty);
        Thread.sleep(1000);
        nestty.loopWatch("/");
        while (true){

        }
    }

    public void loopWatch(String path){
        try {
            List<String> paths = zooKeeper.getChildren(path,nestty);
            if(paths.isEmpty()){
                System.out.println(path+" have no children,data are "+new String(zooKeeper.getData(path,true,stat)));
                zooKeeper.exists(path,nestty);
                return;
            }
            System.out.println("parent path is: "+path+", children are: "+paths);
            for(String childPath: paths){
                if (path.equals("/")){
                    loopWatch("/"+childPath);
                }else{
                    loopWatch(path+"/"+childPath);
                }
            }
        } catch (KeeperException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void process(WatchedEvent event) {
        if (Event.KeeperState.SyncConnected == event.getState()) {
            System.out.println("========event get started========"+new Date());
            if(Event.EventType.None == event.getType() && null == event.getPath()){
                // 链接时的监听事件
                System.out.println("get connection msg!");
//                try {
//                    zooKeeper.exists("/nestty",nestty);
//                } catch (KeeperException e) {
//                    e.printStackTrace();
//                } catch (InterruptedException e) {
//                    e.printStackTrace();
//                }
            } else { // 内容变动时的监听
                try {
                    //监听当前路径节点事件,exists只能监听到当前路径，子节点的仍是须要getchildren
                    //一次watch处理，只针对一次事件，后续再触发事件须要再次设置监视
                    zooKeeper.exists(event.getPath(),nestty);
                    if(event.getType().equals(Event.EventType.NodeChildrenChanged)){
                        //监听子节点变化事件
                        loopWatch(event.getPath());
                    }
                    zooKeeper.getChildren(event.getPath(),nestty);
                    System.out.println("event path is: "+event.getPath()+", event type is: "+event.getType()+", get msg content data:"
                            + new String(zooKeeper.getData(event.getPath(),true,stat)));
                    System.out.println("get msg stat:czxid=" + stat.getCzxid()
                            + ";mzxid=" + stat.getMzxid() + ";version="  + stat.getVersion());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public void processResult(int rc, String path, Object ctx, Stat stat) {

        System.out.println("xzxzc");
    }
}

只须要依赖

org.apache.zookeeper,pom文件以下

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.cqq</groupId>
    <artifactId>nestty</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <zookeeper.version>3.4.12</zookeeper.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>${zookeeper.version}</version>
        </dependency>
        <!--<dependency>-->
            <!--<groupId>org.springframework.boot</groupId>-->
            <!--<artifactId>spring-boot-starter-web</artifactId>-->
        <!--</dependency>-->
    </dependencies>

</project>