使用maven多模块构建dubbo第一个分布式HelloWorld

一时失言乱红尘 2022-07-15 12:16 182阅读 0赞

至于为什么要用maven多模块构建项目，和dubbo是做什么的就不多说了，直接开始。

首先创建一个maven项目作为root模块 命名为mydubbo，并删除其中的src目录（不需要）

![Center][]

除外我们需要Spring，zookeeper的依赖

mydubbo->pom.xml

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com</groupId>
        <artifactId>mydubbo</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <properties>
            <spring.version>3.2.4.RELEASE</spring.version>
        </properties>
        <modules>
            <module>myProvider</module>
            <module>myConsumer</module>
            <module>myService</module>
        </modules>
        <dependencies>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>dubbo</artifactId>
                <version>2.5.3</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            
            <dependency>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
                <version>3.4.6</version>
            </dependency>
            
            <dependency>
                <groupId>com.github.sgroschupf</groupId>
                <artifactId>zkclient</artifactId>
                <version>0.1</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>${spring.version}</version>
            </dependency>
        </dependencies>
    </project>

然后创建三个maven子模块分别为myService、myProvider、myConsumer

myService:功能接口模块

myProvider:dubbo提供者

myConsumer:dubbo消费者

因为消费者和提供者的功能接口一致，所以都依赖myService模块（myService的项目packing 为 jar）

![Center 1][]

myProvider->pom.xml

myConsumer->pom.xml

myService->pom.xml

在myService中建立一个Interface，命名为HelloService，具体如下

![Center 2][]

HelloService.java

package com.service;
    
    /**
     * Created by yuyufeng on 2016/11/16.
     */
    public interface HelloService {
        String speakHello(String name);
    }

现在，我们需要install myService这个项目，产生一个可以依赖的jar供其它引用者使用。

myProvider的依赖就有myService产生的jar

![Center 3][]

现在，开始编写dubbo提供者myProvider的代码

首先，需要提供HelloService的实现

![Center 4][]

HelloServiceImpl.java

package com.service.impl;
    
    import com.service.HelloService;
    
    /**
     * Created by yuyufeng on 2016/11/16.
     */
    public class HelloServiceImpl implements HelloService {
        public String speakHello(String name) {
            return "你好：" + name;
        }
    }

然后使 用Spring配置声明暴露服务，建立一个provider.xml 如下

<?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">
    
        
        <dubbo:application name="hello-provider"  />
    
        
        <dubbo:registry address="zookeeper://127.0.0.1:2181" />
    
        
        <dubbo:protocol name="dubbo" port="20880" />
    
        
        <dubbo:service interface="com.service.HelloService" ref="helloService" />
    
        
        <bean id="helloService" class="com.service.impl.HelloServiceImpl" />
    
    </beans>

本次dubbo使用的注册中心为zookeeper，所以需要在本地启动一个zookeeper服务。  
最后，我们就可以启动提供者服务了，启动类如下：

package com.service.impl;
    
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import java.io.IOException;
    
    /**
     * Created by yuyufeng on 2016/11/16.
     */
    public class ProviderServer{
        public static void main(String[] args) throws IOException {
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("provider.xml");
            context.start();

//按任意键退出
            System.in.read();
    
        }
    }

启动之后我们可以在zookeeper注册中心看到我们的服务提供者已经注册在上面

![Center 5][]

然后，就编写个消费者通过dubbo来调以下远程的服务吧

消费者通过Spring配置引用远程服务spring配置文件如下：

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">
        
        <dubbo:application name="hello-consumer"  />
        
        <dubbo:registry address="zookeeper://127.0.0.1:2181" />
        
        <dubbo:reference id="helloService" interface="com.service.HelloService" />
    </beans>

消费者启动类

ConsumerClient.java

import com.service.HelloService;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    /**
     * Created by yuyufeng on 2016/11/16.
     */
    public class ConsumerClient {
        public static void main(String[] args) {
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("consumer.xml");
            HelloService helloService = (HelloService) context.getBean("helloService");
            String result = helloService.speakHello("yyf");
            System.out.println(result);
        }
    }

运行改类，结果如下：

![Center 6][]

可以看到，远程服务调用成功。

[Center]: /images/20220715/c30db126093945ffa2c1941570b8839d.png
[Center 1]: /images/20220715/41e38236204c45eebfcae4bcc607de2e.png
[Center 2]: /images/20220715/0b5087e24187413082c4714f5c13651c.png
[Center 3]: /images/20220715/82c2c44598ac4892899a9d20e71d9f17.png
[Center 4]: /images/20220715/f6d38140906d4f05815dfea121c13dab.png
[Center 5]: /images/20220715/44d019d9044d47dc8baf1f00cef6f0a2.png
[Center 6]: /images/20220715/b5936c089752407bb404ee0f5a75f580.png