Dubbo之旅--Provider示例

       在本篇文章中我们将通过集体的示例来对Dubbo的提供和消费进行代码层面的认识.这里所介绍的是基本的提供者和消费者通过Spring容器来进行相关的提供和消费的服务.首先看整个示例的项目结构如下:

      我们通过Maven的方式来进行示例,其中dubbo-demo-api为提供者所定义的接口,项目结构如下:

此项目里的内容很简单,为服务的一个接口DemoService:

/dubbo-demo/dubbo-demo-api/src/main/java/org/pactera/dubbo/DemoService.java

packageorg.pactera.dubbo;

/**

 *

 * @author Qing

 *

 */

publicinterface DemoService {

    public String sayHello(String str);

}

      Dubbo-demo-provider为服务提供者的示例项目,结构如下图:

Dubbo-demo-consumer为服务消费者的示例项目,结构如下图:

以上是整个示例程序的整体框架.

接下来我们将从提供者的项目入手开始.在提供者的项目里先要对相关提供的服务进行配置.

1   在Dubbo-demo-provider的项目里我们需要用到Dubbo,Zookeeper,以及dubbo-demo-api的相关java包,因此需要在pom.xml对其进行引用,如下:

    <dependencies>

        <dependency>

           <groupId>org.pactera.dubbo</groupId>

           <artifactId>dubbo-demo-api</artifactId>

           <version>1.0-SNAPSHOT</version>

        </dependency>

        <dependency>

           <groupId>com.alibaba</groupId>

           <artifactId>dubbo</artifactId>

           <version>2.4.10</version>

        </dependency>

        <dependency>

           <groupId>com.101tec</groupId>

           <artifactId>zkclient</artifactId>

            <version>0.3</version>

        </dependency>

        <dependency>

           <groupId>junit</groupId>

           <artifactId>junit</artifactId>

           <version>3.8.1</version>

            <scope>test</scope>

        </dependency>

    </dependencies>

2  接下来为了能够让Dubbo的提供者通过Spring方式加载,我们需要对其进行相关配置,如下文件内容.

/dubbo-demo/dubbo-demo-provider/src/main/resources/dubbo-demo-provider.xml

<?xmlversion="1.0" encoding="UTF-8"?>

<beansxmlns="http://www.springframework.org/schema/beans"

   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

   xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"

   xsi:schemaLocation="http://www.springframework.org/schema/beans

        http://www.springframework.org/schema/beans/spring-beans.xsd

        http://code.alibabatech.com/schema/dubbo

        http://code.alibabatech.com/schema/dubbo/dubbo.xsd

        ">

    <!-- 提供方应用信息，用于计算依赖关系 -->

    <dubbo:applicationname="hello-world-app"  />

     <!-- 使用zookeeper广播注册中心暴露服务地址 -->

    <dubbo:registryprotocol="zookeeper" address="127.0.0.1:2181" />

    <!-- 用dubbo协议在20880端口暴露服务 -->

    <dubbo:protocol name="dubbo"port="20881" />

    <dubbo:monitorprotocol="registry"></dubbo:monitor>

    <!-- 声明需要暴露的服务接口 -->

    <dubbo:serviceinterface="org.pactera.dubbo.DemoService" ref="demoService"/>

    <!-- 和本地bean一样实现服务 -->

    <bean id="demoService"class="org.pactera.dubbo.provider.DemoServiceImpl" />

</beans>

3  需要将dubbo提供的服务接口进行实现.

/dubbo-demo/dubbo-demo-provider/src/main/java/org/pactera/dubbo/provider/DemoServiceImpl.java

packageorg.pactera.dubbo.provider;

importcom.alibaba.dubbo.rpc.RpcContext;

importlombok.extern.slf4j.Slf4j;

importorg.pactera.dubbo.DemoService;

@Slf4j

publicclass DemoServiceImpl implements DemoService {

    public String sayHello(String str) {

      System.out.println("reqInfo: "+ str + ", request form consumer: " +RpcContext.getContext().getRemoteHost());

        return "Hello " + str;

    }

}

4 接下来我们需要再写一个提供者启动服务的程序,主要是用来启动Spring容器,并注入相关的服务,同时将提供者的内容注册到Zookeeper中.

 启动程序如下:

/dubbo-demo/dubbo-demo-provider/src/main/java/org/pactera/dubbo/Bootstrap.java

packageorg.pactera.dubbo;

importcom.google.common.util.concurrent.AbstractIdleService;

importlombok.extern.slf4j.Slf4j;

importorg.springframework.context.support.ClassPathXmlApplicationContext;

@Slf4j

publicclass Bootstrap extends AbstractIdleService {

    private ClassPathXmlApplicationContextcontext;

    public static void main(String[] args) {

        Bootstrap bootstrap = new Bootstrap();

        bootstrap.startAsync();

        try {

            Object lock = new Object();

            synchronized (lock) {

                while (true) {

                    lock.wait();

                }

            }

        } catch (InterruptedException ex) {

            System.err.println("ignoreinterruption");

        }

    }

    /**

     * Start the service.

     */

    @Override

    protected void startUp() throws Exception {

        context = newClassPathXmlApplicationContext("dubbo-demo-provider.xml");

        context.start();

        context.registerShutdownHook();

       System.out.println("----------------provider service startedsuccessfully------------");

    }

    /**

     * Stop the service.

     */

    @Override

    protected void shutDown() throws Exception{

        context.stop();

       System.out.println("-------------service stoppedsuccessfully-------------");

    }

}

       5    提供者服务启动日志:

         至此,服务者Provider的示例基本上已经结束,如果读者配置监控中心的话,可以打开监控中心搜索demoService,你便可以在监控中心看到此提供者服务的具体信息.限于篇幅的原因,关于消费者的相关示例将在接下来的文章进行阐述.