dubbo实践

最近公司准备重构内部服务模块，准备使用dubbo，故研究一下。

官方文档：http://alibaba.github.io/dubbo-doc-static/Home-zh.htm

1. 用maven创建一个项目(父模块)，将src目录删除：

mvn archetype:generate -DgroupId=com.winter.dubbo -DartifactId=dubbo-parent -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false -DarchetypeCatalog=internal

2. 修改pom.xml文件，将packaging设为pom。并增加以下依赖：

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>3.2.5.RELEASE</version>
</dependency>
 
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>dubbo</artifactId>
    <version>2.4.9</version>
</dependency>
     
<dependency>
    <groupId>org.apache.zookeeper</groupId>
    <artifactId>zookeeper</artifactId>
    <version>3.3.3</version>
    <exclusions>
        <exclusion>
        <groupId>com.sun.jmx</groupId>
        <artifactId>jmxri</artifactId>
        </exclusion>
        <exclusion>
        <groupId>com.sun.jdmk</groupId>
        <artifactId>jmxtools</artifactId>
        </exclusion>
        <exclusion>
        <groupId>javax.jms</groupId>
        <artifactId>jms</artifactId>
        </exclusion>
    </exclusions>
</dependency>
 
<dependency>
    <groupId>com.github.sgroschupf</groupId>
    <artifactId>zkclient</artifactId>
    <version>0.1</version>
</dependency>
 
<dependency>
    <groupId>com.netflix.curator</groupId>
    <artifactId>curator-framework</artifactId>
    <version>1.1.16</version>
</dependency>

3.创建子模块：provider、customer、api

　　mvn archetype:generate -DgroupId=com.winter.dubbo -DartifactId=provider -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false -DarchetypeCatalog=internal

　　mvn archetype:generate -DgroupId=com.winter.dubbo -DartifactId=customer -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false -DarchetypeCatalog=internal

　　mvn archetype:generate -DgroupId=com.winter.dubbo -DartifactId=api -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false -DarchetypeCatalog=internal

将provider、customer、api模块移到父模块目录下，同时在父模块下的pom.xml文件中增加模块依赖：

<modules>
    <module>provider</module>
    <module>customer</module>
    <module>api</module>
</modules>

分别修改provider、customer、api模块的pom.xml文件，增加一下内容：

  <parent>
      <groupId>com.winter.dubbo</groupId>
      <artifactId>dubbo-parent</artifactId>
      <version>1.0-SNAPSHOT</version>
      <relativePath>../pom.xml</relativePath>
  </parent>

由于provider、customer模块都依赖api模块，记着在它们的pom.xml增加api的依赖：

    <dependency>
      <groupId>com.winter.dubbo</groupId>
      <artifactId>api</artifactId>
      <version>1.0-SNAPSHOT</version>
    </dependency>

最终形成的目录结构

4. 在api模块中创建相关服务接口

package com.winter.dubbo.api;

public interface DemoService {

    String sayHello(String name);
}

5. 在provider模块中实现相关服务

package com.winter.dubbo.provider;

public class DemoServiceImpl implements DemoService {
    public String sayHello(String name) {
        return "Hello " + name;
    }
}

6. 在provider模块中创建服务提供者、以及服务的实现

package com.winter.dubbo.provider;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ProviderServer {

    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"provider.xml"});
        context.start();
        System.out.println("请按任意键退出");
        System.in.read(); // 按任意键退出
    }

}

package com.winter.dubbo.provider;

import com.winter.dubbo.api.DemoService;

public class DemoServiceImpl implements DemoService {

    public String sayHello(String name) {
        return "Hello " + name;
    }

}

7. 在customer模块中创建消费者

package com.winter.dubbo.customer;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Application {
    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"customer.xml"});
        context.start();
    }
}

package com.winter.dubbo.customer;

import com.alibaba.dubbo.config.annotation.Reference;
import com.winter.dubbo.api.DemoService;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;

@Component
public class TestClient {

    @Reference
    private DemoService demoService;

    @PostConstruct
    public void run() {
        String res = demoService.sayHello("Dubbo");
        System.out.println( res ); // 显示调用结果
    }

}

8. 在provider模块的resources下创建provider.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: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:application name="dubbo-service"  />

    <!-- 使用multicast广播注册中心暴露服务地址 -->
    <!--  <dubbo:registry address="multicast://224.5.6.7:1234" /> -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181" client="zkclient" />

    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="20880" />

    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service interface="com.winter.dubbo.api.DemoService" ref="demoService" />

    <!-- 和本地bean一样实现服务 -->
    <bean id="demoService" class="com.winter.dubbo.provider.DemoServiceImpl" />

<dubbo:annotation package="com.winter.dubbo"/>

</beans>

9. 在customer模块的resources下创建consumer.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: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
        ">

    <!-- 消费方应用名，用于计算依赖关系，不是匹配条件，不要与提供方一样 -->
    <dubbo:application name="dubbo-consumer"  />

    <!-- 使用multicast广播注册中心暴露发现服务地址 -->
    <!--   <dubbo:registry address="multicast://224.5.6.7:1234" /> -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181" />

    <!-- 生成远程服务代理，可以和本地bean一样使用demoService -->
    <dubbo:reference id="demoService" interface="com.winter.dubbo.api.DemoService" />

    <!-- 扫描注解包路径，多个包用逗号分隔，不填pacakge表示扫描当前ApplicationContext中所有的类 -->
    <dubbo:annotation package="com.winter.dubbo"/>


</beans>

10. 测试

先保证zookeeper已经启动，在通过ProviderServer.java启动服务，最后运行customer模块下的Application.java来测试，你就能看到经典的“Hello Dubbo”。

11.详细代码请参考：https://git.oschina.net/winter550/dubbo-demo