Java 语言定义服务

示例使用 Spring XML 配置方式进行演示。

除此之外,Dubbo Java 还提供了包括注解、API、配置文件、spring boot等多种启动与接入方式,具体可参见配置章节具体描述。

下载示例代码

示例代码在 dubbo-samples

  1. 下载源码
$ git clone -b master https://github.com/apache/dubbo-samples.git
  1. 进入示例目录
$ cd dubbo-samples/dubbo-samples-basic

快速运行示例

在 dubbo-samples-basic 目录

  1. 编译 Provider
$ mvn clean compile -Pprovider
  1. 运行 Provider
$ java -jar ./target/provider.jar 
  1. 编译 Consumer
$ mvn clean compile -Pconsumer
  1. 运行 consumer
$ java -jar ./target/consumer.jar 

详细解释

定义服务接口

DemoService.java

package org.apache.dubbo.samples.basic.api;

public interface DemoService {
    String sayHello(String name);
}

在服务提供方实现接口

DemoServiceImpl.java

public class DemoServiceImpl implements DemoService {
    @Override
    public String sayHello(String name) {
        System.out.println("[" + new SimpleDateFormat("HH:mm:ss").format(new Date()) + "] Hello " + name +
                ", request from consumer: " + RpcContext.getContext().getRemoteAddress());
        return "Hello " + name + ", response from provider: " + RpcContext.getContext().getLocalAddress();
    }
}

用 Spring 配置声明暴露服务

provider.xml:

<bean id="demoService" class="org.apache.dubbo.samples.basic.impl.DemoServiceImpl"/>

<dubbo:service interface="org.apache.dubbo.samples.basic.api.DemoService" ref="demoService"/>

服务消费者

引用远程服务

consumer.xml:

<dubbo:reference id="demoService" check="true" interface="org.apache.dubbo.samples.basic.api.DemoService"/>

加载Spring配置,并调用远程服务

Consumer.java

public static void main(String[] args) {
    ...
    DemoService demoService = (DemoService) context.getBean("demoService");
    String hello = demoService.sayHello("world");
    System.out.println(hello);
}