duboo注解使用详解

一、背景

随着互联网的发展，网站应用的规模不断扩大，常规的垂直应用架构已无法应对，分布式服务架构以及流动计算架构势在必行。

当越来越的的接口与实现类的增加后，duboo的xml配置会越来越多，为了防止几百几千行的代码，减少开发人员配置xml的工作量，使用duboo的注解模式，减少配置多出问题多的可能性！

二、Dubbo使用案例

Duboo注解

接口类项目：DubboServiceInterface

仅仅是一个接口类项目！接口是普通接口！

注意：将接口类项目打包成jar分别放入服务端项目跟客户端项目！

服务端项目：DubboServiceProvider

实现类fooserviceImpl.java

package com.alibaba.dubbo.demo.imp;
import com.alibaba.dubbo.config.annotation.Service;
import com.alibaba.dubbo.demo.DemoService;
@Service(version="1.0")
public class FooServiceImpl implements DemoService {
 @Override
 public String sayHello(String name) {
        return "Hello " + name;
    }
}

web.xml 配置扫描内容

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>DubboServiceProvider</display-name>
 <servlet>
 <servlet-name>spring</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
 <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
 <servlet-name>spring</servlet-name>
 <url-pattern>*</url-pattern>
 </servlet-mapping> 
   <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>
    <context-param>
 <param-name>contextConfigLocation</param-name> <param-value>classpath*:applicationContext.xml</param-value>
 </context-param>
</web-app>

applicationContext.xml 配置

<?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">  
        
<!-- 服务端- 服务提供方   -->
   <!-- 公共信息，也可以用dubbo.properties配置 -->
   <dubbo:application name="test" />
<!--    链接zookeeper -->
   <dubbo:registry address="zookeeper://127.0.0.1:2181/" group="test"/>
   <dubbo:consumer timeout="5000"/>
   <!-- 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.unj.dubbotest.serviceImp" /> 
   
 <!-- xml配置 ： 声明需要暴露的服务接口 -->
<!--      <dubbo:service interface="com.alibaba.dubbo.demo.DemoService" ref="demoService" /> -->
    <!-- xml配置 ：和本地bean一样实现服务-->
<!--     <bean id="demoService" class="com.unj.dubbotest.serviceImp.FooServiceImpl" /> -->
</beans>

测试类Provider

package com.alibaba.dubbo.test;
import java.io.IOException;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Provider {
 @Before
 public void setUp() throws Exception {
 }
 @Test
 public void testMain() throws IOException {
 ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
 new String[] { "applicationContext.xml" });
 context.start();
 System.in.read();// 按任意键退出 
 }
}

lib下的jar包

客户端项目：DubboServiceConsumer

web.xml 配置扫描内容

applicationContext.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"  
 xmlns:context="http://www.springframework.org/schema/context"
    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">  
        
<!-- 客户端- 服务消费方   -->
   <!-- 公共信息，也可以用dubbo.properties配置 -->
   <dubbo:application name="xx" />
   <dubbo:registry address="zookeeper://127.0.0.1:2181" />
   <dubbo:consumer timeout="5000"/>
 <!-- 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.unj.dubbotest.action" />
</beans>

测试类:Consumer

package com.unj.dubbotest.action;
import java.io.IOException;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.alibaba.dubbo.config.annotation.Reference;
import com.alibaba.dubbo.demo.DemoService;
public class Consumer{
 @Reference(version = "1.0")
 private DemoService demoService;
 @Test
  public  void mainTest() throws IOException {
   ClassPathXmlApplicationContext context =new ClassPathXmlApplicationContext(
   new String[] {"applicationContext.xml"}); 
         context.start(); 
          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 
     }
}

lib下的jar包