Motan源码阅读--调用示例

调用示例

同步调用

Pom中添加依赖

<dependency>
     <groupId>com.weibo</groupId>
     <artifactId>motan-core</artifactId>
     <version>RELEASE</version>
 </dependency>
 <dependency>
     <groupId>com.weibo</groupId>
     <artifactId>motan-transport-netty</artifactId>
     <version>RELEASE</version>
 </dependency>
 
 <!-- only needed for spring-based features -->
 <dependency>
     <groupId>com.weibo</groupId>
     <artifactId>motan-springsupport</artifactId>
     <version>RELEASE</version>
 </dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context</artifactId>
     <version>4.2.4.RELEASE</version>
 </dependency>

为调用方和服务方建立公共接口

src/main/java/quickstart/FooService.java

package quickstart;

public interface FooService {
    public String hello(String name);
}

编写业务接口逻辑，建立并启动RPC Server

src/main/java/quickstart/FooServiceImpl.java

package quickstart;

public class FooServiceImpl implements FooService {

    public String hello(String name) {
        System.out.println(name + " invoked rpc service");
        return "hello " + name;
    }
}

src/main/resources/motan_server.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:motan="http://api.weibo.com/schema/motan"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
   http://api.weibo.com/schema/motan http://api.weibo.com/schema/motan.xsd">

    <!-- service implemention bean -->
    <bean id="serviceImpl" class="quickstart.FooServiceImpl" />
    <!-- exporting service by Motan -->
    <motan:service interface="quickstart.FooService" ref="serviceImpl" export="8002" />
</beans>

src/main/java/quickstart/Server.java

package quickstart;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Server {

    public static void main(String[] args) throws InterruptedException {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:motan_server.xml");
        System.out.println("server start...");
    }
}

执行Server类中的main函数会启动Motan服务，并监听8002端口。

建立并执行RPC Client

src/main/resources/motan_client.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:motan="http://api.weibo.com/schema/motan"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
   http://api.weibo.com/schema/motan http://api.weibo.com/schema/motan.xsd">

    <!-- reference to the remote service -->
    <motan:referer id="remoteService" interface="quickstart.FooService" directUrl="localhost:8002"/>
</beans>

src/main/java/quickstart/Client.java

package quickstart;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;


public class Client {

    public static void main(String[] args) throws InterruptedException {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:motan_client.xml");
        FooService service = (FooService) ctx.getBean("remoteService");
        System.out.println(service.hello("motan"));
    }
}

执行Client类中main函数将执行一次远程调用，并输出结果。

异步调用

异步调用和同步调用基本配置同样，只须要在接口类中加@MotanAsync注解，而后Client端稍做修改，server端不须要作任何修改。

package quickstart;

@MotanAsync
public interface FooService {
    public String hello(String name);
}

编译时，Motan会自动生成异步service类，生成的类名为service名加上Async。 在client配置motan-client.xml时，在同步调用配置的基础上，只须要修改refer的interface为Motan自动生成的接口类便可。

<motan:referer id="remoteService" interface="quickstart.FooServiceAsync" directUrl="localhost:8002"/>

异步使用方式以下：

public static void main(String[] args) {
    ApplicationContext ctx = new ClassPathXmlApplicationContext(new String[] {"classpath:motan_client.xml"});

    FooServiceAsync service = (FooServiceAsync) ctx.getBean("remoteService");

    // sync call
    System.out.println(service.hello("motan"));

    // async call
    ResponseFuture future = service.helloAsync("motan async ");
    System.out.println(future.getValue());

    // multi call
    ResponseFuture future1 = service.helloAsync("motan async multi-1");
    ResponseFuture future2 = service.helloAsync("motan async multi-2");
    System.out.println(future1.getValue() + ", " + future2.getValue());

    // async with listener
    FutureListener listener = new FutureListener() {
        @Override
        public void operationComplete(Future future) throws Exception {
            System.out.println("async call "
                    + (future.isSuccess() ? "sucess! value:" + future.getValue() : "fail! exception:"
                            + future.getException().getMessage()));
        }
    };
    ResponseFuture future3 = service.helloAsync("motan async multi-1");
    ResponseFuture future4 = service.helloAsync("motan async multi-2");
    future3.addListener(listener);
    future4.addListener(listener);
}

集群调用示例

在分布式环境下，motan的使用须要依赖于外部服务发现组件，目前支持consul或zk。

使用Consul做为注册中心

server和client中添加moan-registry-consul依赖

<dependency>
    <groupId>com.weibo</groupId>
    <artifactId>motan-registry-consul</artifactId>
    <version>RELEASE</version>
</dependency>

在server和client的配置文件中分别增长consul registry定义

<motan:registry regProtocol="consul" name="my_consul" address="127.0.0.1:8500"/>

将motan client及server配置改成经过registry服务发现

Client

<motan:referer id="remoteService" interface="quickstart.FooService" registry="my_consul"/>

Server

<motan:service interface="quickstart.FooService" ref="serviceImpl" registry="my_consul" export="8002" />

Server启动后，须要显示调用心跳开关，注册到consul

MotanSwitcherUtil.setSwitcherValue(MotanConstants.REGISTRY_HEARTBEAT_SWITCHER, true)

zookeeper的实现和Consul相似。