dubbo快速入门

为什么要学习dubbo 这里不多做说明，有需要可自行百度

说明：基于zookeeper 作为注册服务中心，

1：新建两个maven 项目，一个作为服务提供者，一个作为服务消费者，如下

dubbo-client  -- 服务消费者
dubbo-provider -- 服务提供者

2：服务端接口代码如下（服务接口作为服务提供者的一个子模块打包成jar包以供调用）

public interface SayHello {

    public  String sayHello(String name);
}

3：接口实现代码如下

public class SayHelloImpl implements SayHello {
    @Override
    public String sayHello(String name) {

        return "hello version 1.0.0"+name;
    }

    public static void main(String[] args) throws  Exception{
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("dubbo-server.xml");
        context.start();
       System.in.read();
    }
}

4：版本升级处理,可通过配置文件指定version,然后在客户端指定调用的版本

public class SayHelloImpl2 implements SayHello {
    @Override
    public String sayHello(String name) {
        return "hello version 2.0.0"+name;
    }

    public static void main(String[] args) throws  Exception{
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("dubbo-server.xml");
        context.start();
       System.in.read();
    }
}

5：服务提供配置xml

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 提供方应用信息，用于计算依赖关系,dubbo-provider这个是项目名 -->
    <dubbo:application name="dubbo-provider"/>
  <!-- 这里使用的注册中心是zookeeper -->
    <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" />
   <!-- 将该接口暴露到dubbo中 ,在做服务升级的时候，为了兼容老版本，可通过 version 可以指定调用的版本-->
    <dubbo:service interface="com.share.dubbo.SayHello" ref="sayHelloImpl" version="1.0.0"/>
    <dubbo:service interface="com.share.dubbo.SayHello" ref="sayHelloImpl2" version="2.0.0"/>
    <bean id="sayHelloImpl" class="com.share.dubbo.SayHelloImpl" />
    <bean id="sayHelloImpl2" class="com.share.dubbo.SayHelloImpl2" />
</beans>

6：客户端调用(引入服务接口jar包)

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

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

   <!-- 提供方应用信息，用于计算依赖关系,dubbo-provider这个是项目名 -->
    <dubbo:application name="dubbo-client" />
    <!-- 这里使用的注册中心是zookeeper -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181" client="zkclient"/>
    <!--通过version 指定调用的版本-->
    <dubbo:reference id="sayHelloImpl" interface="com.share.dubbo.SayHello" version="2.0.0"/>
</beans>

7：客服端调用服务

ublic class SayHelloClient {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
                new String[] { "dubbo-client.xml" });
        context.start();

       SayHello hello = (SayHello)context.getBean("sayHelloImpl");
     String name =  hello.sayHello("我是来测试的");
        System.out.println(name);
    }
}

测试：
启动zookeeper 后，在启动服务端，然后会在zookeeper 中看到新注册的服务中心地址，然后在启动客户端检验服务调用是否成功

ls /dubbo/com.share.dubbo.SayHello/providers
[dubbo%3A%2F%2F169.254.72.117%3A20880%2Fcom.share.dubbo.SayHello%3Fanyhost%3Dtrue%26application%3Ddubbo-provider%26dubbo%3D2.5.6%26generic%3Dfalse%26interface%3Dcom.share.dubbo.SayHello%26methods%3DsayHello%26pid%3D48779%26revision%3D1.0.0%26side%3Dprovider%26timestamp%3D1533543075021%26version%3D1.0.0, dubbo%3A%2F%2F169.254.72.117%3A20880%2Fcom.share.dubbo.SayHello2%3Fanyhost%3Dtrue%26application%3Ddubbo-provider%26dubbo%3D2.5.6%26generic%3Dfalse%26interface%3Dcom.share.dubbo.SayHello%26methods%3DsayHello%26pid%3D48779%26revision%3D2.0.0%26side%3Dprovider%26timestamp%3D1533543090459%26version%3D2.0.0]

以上完成了 dubbo 简单的服务调用完成，事例代码稍后会上传github上以供下载