Dubbo系列(3)_官方Demo说明

时间:2022-08-14 13:31:21
一、本文目的
    通过Dubbo的官方Demo介绍,学会搭建一个简单的Dubbo程序,包括服务端、客户端、接口等。

二、Demo概况
     1、Demo分为三个项目
            a) dubbo-demo-api:服务接口,服务端和客户端都需要引用
b)dubbo-demo-provider:包含对服务接口的引用和实现
c)dubbo-demo-consumer:包含对服务接口的引用和使用
2、Demo三个项目的父项目是:dubbo-demo

三、Demo引用的Jar包说明
  1. JDK:1.6
  2. Dubbo版2号:2.5.4-SNAPSHOT
  3. Spring版本号:3.2.16.RELEASE<
  4. ZooKeeper版本号:3.3.3
  5. Jedis版本号:2.1.0
  6. Netty版本号:3.2.5.Final
  7. 其它:参考pom.xml     https://github.com/alibaba/dubbo/blob/master/pom.xml

四、Demo代码说明
1、服务接口:dubbo-demo-api
          本项目只包含一个接口及一个接口方法
1
2
3
4
5
6
7
package com.alibaba.dubbo.demo;
 
public interface DemoService {
 
    String sayHello(String name);
 
}

    2、服务实现:dubbo-demo-provider

a) 服务端包含了对dubbo-demo-api的引用及实现

1
2
3
4
5
<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>dubbo-demo-api</artifactId>
        <version>${project.parent.version}</version>
    </dependency>

b) 配置文件(dubbo-demo-provider.xml

其中<dubbo:servcie> 定义一个对外提供的接口,通过ref关联到具体的实现代码

1
2
3
4
5
6
7
8
9
10
11
     
    <bean id="demoService" class="com.alibaba.dubbo.demo.provider.DemoServiceImpl" />
     
    <dubbo:service interface="com.alibaba.dubbo.demo.DemoService" ref="demoService" />
     
</beans>

c) 实现代码(DemoServiceImpl)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
package com.alibaba.dubbo.demo.provider;
 
import java.text.SimpleDateFormat;
import java.util.Date;
 
import com.alibaba.dubbo.demo.DemoService;
import com.alibaba.dubbo.rpc.RpcContext;
 
public class DemoServiceImpl implements DemoService {
 
    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 form provider: " + RpcContext.getContext().getLocalAddress();
    }
     
}

    3、服务消费:dubbo-demo-consumer

  a) 消费端也包含了对dubbo-demo-api的引用
1
2
3
4
5
<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>dubbo-demo-api</artifactId>
        <version>${project.parent.version}</version>
    </dependency>

b) 配置文件(dubbo-demo-consumer.xml)

通过<dubbo:reference>引用一个服务接口,客户端使用远程接口方法就和调用本地方法一致

1
2
3
4
5
6
7
8
9

c) 消费端调用代码:DemoAction.java

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
package com.alibaba.dubbo.demo.consumer;
 
import java.text.SimpleDateFormat;
import java.util.Date;
 
import com.alibaba.dubbo.demo.DemoService;
 
public class DemoAction {
     
    private DemoService demoService;
 
    public void setDemoService(DemoService demoService) {
        this.demoService = demoService;
    }
 
    public void start() throws Exception {
        for (int i = 0; i < Integer.MAX_VALUE; i ++) {
            try {
                String hello = demoService.sayHello("world" + i);
                System.out.println("[" + new SimpleDateFormat("HH:mm:ss").format(new Date()) + "] " + hello);
            } catch (Exception e) {
                e.printStackTrace();
            }
            Thread.sleep(2000);
        }
    }
 
}