Gearman使用示例

最近的一个旧项目重构过程中，使用到了gearman这个开源项目，简单来讲，这是一个类似MQ的异步系统，一边派发任务，一边处理任务(有类似MQ中的消息发送方与接收方)，目前支持java，php等多种语言，缺点是存在单点问题（server的HA官方没有提供方案，需要二次开发）。

官网地址：http://www.gearman.org

下面是java语言的示例：

注：gearman的java客户端实例有好几个版本，不同的版本之间相差巨大，建议使用官方推荐的最新版，地址为https://github.com/gearman/java-service

一、spring配置

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 5
 6     <bean id="gearmanImpl" class="org.gearman.impl.GearmanImpl"></bean>
 7
 8     <bean id="gearmanServer" class="org.gearman.impl.server.remote.GearmanServerRemote">
 9         <constructor-arg index="0" ref="gearmanImpl"/>
10         <constructor-arg index="1">
11             <bean class="java.net.InetSocketAddress">
12                 <constructor-arg index="0" value="localhost"/>
13                 <constructor-arg index="1" value="4730"/>
14             </bean>
15         </constructor-arg>
16     </bean>
17
18     <bean id="gearmanClient" class="org.gearman.impl.client.ClientImpl">
19         <constructor-arg index="0" ref="gearmanImpl"/>
20     </bean>
21
22     <bean id="gearmanWorker" class="org.gearman.impl.worker.GearmanWorkerImpl">
23         <constructor-arg index="0" ref="gearmanImpl"/>
24     </bean>
25
26
27 </beans>

二、任务发送方(也称Client)

import org.gearman.GearmanJobEvent;
import org.gearman.GearmanJobReturn;
import org.gearman.GearmanServer;
import org.gearman.impl.client.ClientImpl;
import org.gearman.impl.server.remote.GearmanServerRemote;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.UnsupportedEncodingException;

/**
 * Created by 菩提树下的杨过 on 6/12/16.
 */
public class DemoClient {

    public static void main(String[] args) throws InterruptedException, UnsupportedEncodingException {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring-gearman-test.xml");
        GearmanServer gearmanServer = ctx.getBean(GearmanServerRemote.class);
        ClientImpl client = ctx.getBean(ClientImpl.class);
        client.addServer(gearmanServer);
        client.submitBackgroundJob("demoTask", "jimmy1".getBytes());//asynchronous commit

        GearmanJobReturn jobReturn = client.submitJob("demoTask", "jimmy2".getBytes());//synchronous commit

        while (!jobReturn.isEOF()) {
            //next job event
            GearmanJobEvent event = jobReturn.poll();
            switch (event.getEventType()) {
                case GEARMAN_JOB_SUCCESS:     //job execute success
                    System.out.println(new String(event.getData(), "utf-8"));
                    break;
                case GEARMAN_SUBMIT_FAIL:     //job submit fail
                case GEARMAN_JOB_FAIL:        //job execute fail
                    System.err.println(event.getEventType() + ": "
                            + new String(event.getData(), "utf-8"));
                default:
            }
        }
        client.shutdown();

    }

}

三、任务处理方(也称Worker)

import org.gearman.GearmanFunction;
import org.gearman.GearmanFunctionCallback;
import org.gearman.GearmanServer;
import org.gearman.GearmanWorker;
import org.gearman.impl.server.remote.GearmanServerRemote;
import org.gearman.impl.worker.GearmanWorkerImpl;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class DemoWorker implements GearmanFunction {

    public static void main(String[] args) throws InterruptedException {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring-gearman-test.xml");
        GearmanServer gearmanServer = ctx.getBean(GearmanServerRemote.class);
        GearmanWorker worker = ctx.getBean(GearmanWorkerImpl.class);
        worker.addFunction("demoTask", new DemoWorker());
        worker.addServer(gearmanServer);
    }

    @Override
    public byte[] work(String function, byte[] data, GearmanFunctionCallback callback) throws Exception {
        if (data != null) {
            String param = new String(data);
            System.out.println("demoWorker => param :" + param);
            return ("return value：" + param).getBytes("utf-8");
        } else {
            return "not receive data!".getBytes("utf-8");
        }
    }
}