十五、curator recipes之DistributedQueue

简介

curator实现了先入先出的分布式消息队列，它采用的是zookeeper的持久化有序节点。

官方文档：http://curator.apache.org/curator-recipes/distributed-queue.html

javaDoc：http://curator.apache.org/apidocs/org/apache/curator/framework/recipes/queue/DistributedIdQueue.html

代码示例

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.queue.DistributedQueue;
import org.apache.curator.framework.recipes.queue.QueueBuilder;
import org.apache.curator.framework.recipes.queue.QueueConsumer;
import org.apache.curator.framework.recipes.queue.QueueSerializer;
import org.apache.curator.framework.state.ConnectionState;
import org.apache.curator.retry.ExponentialBackoffRetry;

import java.io.UnsupportedEncodingException;

public class DistributedQueueDemo {
    private static CuratorFramework client = CuratorFrameworkFactory.newClient("localhost:2181", new ExponentialBackoffRetry(3000, 2));
    private static String path = "/queue/0001";
    private static DistributedQueue<String> queue;
    static {
        client.start();
    }

    public static void main(String[] args) throws Exception {
        QueueConsumer<String> consumer = new QueueConsumer<String>() {
            @Override
            public void stateChanged(CuratorFramework curatorFramework, ConnectionState connectionState) {
                System.out.println("state changed");
            }

            @Override
            public void consumeMessage(String s) {
                System.out.println("消费数据：" + s);
            }
        };
        queue = QueueBuilder.builder(client, consumer, new QueueSerializer<String>() {
            @Override
            public byte[] serialize(String s) {
                try {
                    return s.getBytes("utf-8");
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
                return null;
            }

            @Override
            public String deserialize(byte[] bytes) {
                return new String(bytes);
            }
        }, path).buildQueue();
        queue.start();
        System.out.println("queue built");
        queue.put("a");
        queue.put("b");
        System.out.println("put ended");
        Thread.sleep(100);
        queue.close();
        Thread.sleep(50000);
        client.close();
    }
}