<> 快速开始

这里先讲一下, 怎么样能快速开始. 新手可以看看,老鸟直接跳过即可.

---

使用maven构建项目,首先引入需要的依赖

      <!-- dubbo -->
      <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.6.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>2.10.0</version>
        </dependency>
        <!-- zookeeper -->
        <dependency>
            <groupId>com.github.sgroschupf</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.1</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.6</version>
            <exclusions>
                <exclusion>
                    <artifactId>jmxtools</artifactId>
                    <groupId>com.sun.jdmk</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>jmxri</artifactId>
                    <groupId>com.sun.jmx</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>jms</artifactId>
                    <groupId>javax.jms</groupId>
                </exclusion>
            </exclusions>
        </dependency>

接下来 编写服务端的接口和实现类以及spring配置文件

接口HelloWorldService

package com.js.dubbo.provider;

public interface HelloWorldService {
    /**
     * 简单接口测试
     *
     * @param greet
     */
    String sayHello(String greet);
}

实现类HelloWorldServiceImpl

package com.js.dubbo.provider;

public class HelloWorldServiceImpl implements HelloWorldService {
    @Override
    public String sayHello(String greet) {
        return System.currentTimeMillis() + " Hello From Dubbo Server :" + greet;
    }
}

provider配置文件spring-dubbo-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://dubbo.apache.org/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 当前应用信息配置 ip也可以是127.0.0.1-->
    <dubbo:application name="providerDemo"/>
    <dubbo:registry address="zookeeper://xx.xx.xx.xxx:2181"/>

    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service interface="com.js.dubbo.provider.HelloWorldService" ref="helloWorldService"/>
    <!-- 本地对象实例 -->
    <bean id="helloWorldService" class="com.js.dubbo.provider.HelloWorldServiceImpl"/>
</beans>

启动类AppServerStart

package com.js.dubbo;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

/**
 * Hello world!
 */
public class AppServerStart {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"spring-dubbo-provider.xml"});
        //blocking the program
        System.in.read();
    }
}

此时,服务端已经编写完成,直接启动 AppServerStart 就开始提供服务了

下面开始编写客户端consumer代码
配置文件spring-dubbo-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://dubbo.apache.org/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 当前应用信息配置 ip也可以是127.0.0.1-->
    <dubbo:application name="providerDemo"/>
    <dubbo:registry address="zookeeper://xx.xx.xx.xxx:2181"/>

    <!-- 像本地使用一样注册对象-->
    <dubbo:reference id="helloWorldService" interface="com.js.dubbo.provider.HelloWorldService"/>
</beans>

测试类AppConsumer

package com.js.dubbo;

import com.js.dubbo.provider.HelloWorldService;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

/**
 * Hello world!
 */
public class AppConsumer {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("spring-dubbo-consumer.xml");
        HelloWorldService hw = (HelloWorldService) ac.getBean(HelloWorldService.class);

        String result = hw.sayHello("dubbo");
        System.err.println(result);
    }
}

此时执行类AppConsumer即可使用helloWorldService提供的服务了.

总结:
本文比较简单 ,把服务端和消费端集成到一起了. 实际开发中, dubbo这种rpc通信基本不会再同一个进程中的(跨jvm通信). 通常的做法是 把服务端的接口文件和接口参数(dto等等) 归入一个单独的接口maven工程中,然后发布到内网,其他用到该项目接口的下游项目,会直接依赖这个发布的接口项目,然后吧接口配置到自身的配置文件中,就像本文后半部分那样 ,使用<dubbo:reference 指令就吧服务引入当前项目了 .就像使用本地接口一样使用这个接口了.