dubbo快速实现demo

 

demo来自dubbo官网

1、创建spring项目

　　创建maven+spring项目

2、pom.xml中导入jar包

 

<?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.gsaftey.com</groupId>
    <artifactId>dubbo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <!-- spring版本号 -->
        <spring.version>4.2.6.RELEASE</spring.version>
        <!-- mybatis版本号 -->
        <mybatis.version>3.4.0</mybatis.version>
        <!-- log4j日志文件管理包版本 -->
        <slf4j.version>1.7.7</slf4j.version>
        <log4j.version>1.2.17</log4j.version>
        <!--jackson版本号-->
        <jackson.version>2.7.1</jackson.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.5.3</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <!-- 表示开发的时候引入，发布的时候不会加载此包 -->
            <!--<scope>test</scope>-->
        </dependency>

        <!-- spring核心包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- mybatis核心包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>

        <!-- mybatis/spring包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.0</version>
        </dependency>

        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4</version>
        </dependency>

        <!-- 导入Mysql数据库链接jar包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.30</version>
        </dependency>
        <!-- 导入dbcp的jar包，用来在applicationContext.xml中配置数据库 -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.2.2</version>
        </dependency>

        <!-- JSTL标签类 -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- 日志文件管理包 -->
        <!-- log start -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <!-- 格式化对象，方便输出日志 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.1.41</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <!-- log end -->

        <!-- 映入JSON -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <!-- 注册到zookeeper -->
        

    </dependencies>

</project>

 

3、服务提供端

3.1、定义服务接口

package com.gsafety.services;

/**
 * Created by hadoop on 2017/6/30.
 */
public interface DemoService {
    String sayHello(String name);
}

 

3.2、接口实现

ackage com.gsafety.service.impl;

import com.gsafety.services.DemoService;

/**
 * Created by hadoop on 2017/6/30.
 */
public class DemoServiceImpl implements DemoService{
    public String sayHello(String name) {
        return "Hello "+name;
    }
}

 

3.3、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="hello-app"  />

    <!-- 使用multicast广播注册中心暴露服务地址 -->
    <dubbo:registry address="multicast://224.5.6.7:1234?unicast=false" />
    

    <!-- 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.gsafety.services.DemoService" ref="demoService" />

    <!-- 和本地bean一样实现服务 -->
    <bean id="demoService" class="com.gsafety.service.impl.DemoServiceImpl" />

</beans>

 

4、服务消费端

4.1、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="consumer-app"  />

    <!-- 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?unicast=false" />
    

    <!-- 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.gsafety.services.DemoService" />

</beans>

 

4.2、远程调用

 

package com.gsafety.entity;


import com.gsafety.services.DemoService;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by hadoop on 2017/6/30.
 */
public class Consumer {
    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
                new String[] {"consumer.xml"});
        context.start();

        DemoService demoService = (DemoService)context.getBean("demoService"); // 获取远程服务代理
        String hello = demoService.sayHello("world"); // 执行远程方法

        System.out.println( hello ); // 显示调用结果


    }

}

 

5、注意问题

• 你可以只运行Demo Provider和Demo Consumer，它们缺省配置为通过Multicast注册中心广播互相发现，建议在不同机器上运行，如果在同一机器上，需设置unicast=false：即：multicast://224.5.6.7:1234?unicast=false，否则发给消费者的单播消息可能被提供者抢占，两个消费者在同一台机器也一样，只有multicast注册中心有此问题。
• 你也可以运行多个Demo Provider和Demo Consumer，来验证软负载均衡，Demo Consumer可以直接启动多个实例，而多个Demo Provider因有端口冲突，可在不同机器上运行，或者修改Demo Provider安装目录下conf/dubbo.properties配置中的dubbo.protocol.port的值。
• 你也可以增加运行Simple Monitor监控中心，它缺省配置为通过Multicast注册中心广播发现Provider和Consumer，并展示出它们的依赖关系，以及它们之间调用的次数和时间。
• 你也可以将Multicast注册中心换成Zookeeper注册中心，安装Zookeeper Registry后，修改Demo Proivder，Demo Consumer，Simple Monitor三者安装目录下的conf/dubbo.properties，将dubbo.registry.address的值改为zookeeper://127.0.0.1:2181，同理，如果换成Redis Registry，值改为redis://127.0.0.1:6379，如果换成Simple Registry，值改为dubbo://127.0.0.1:9090
• 服务消费者的version必须和服务提供者的version一致
• 注意：multicast地址不能配成127.0.0.1，也不能配成机器的IP地址，必须是D段广播地址，也就是：224.0.0.0到239.255.255.255之间的任意地址