Dubbo是一个分布式服务框架，致力于提供高性能和透明化的RPC远程服务调用方案，以及SOA服务治理方案。简单的说，dubbo就是个服务框架，如果没有分布式的需求，其实是不需要用的，只有在分布式的时候，才有dubbo这样的分布式服务框架的需求，并且本质上是个服务调用的东东，说白了就是个远程服务调用的分布式框架（告别Web Service模式中的WSdl，以服务者与消费者的方式在dubbo上注册）。
其核心部分包含:
1. 远程通讯: 提供对多种基于长连接的NIO框架抽象封装，包括多种线程模型，序列化，以及“请求-响应”模式的信息交换方式。
2. 集群容错: 提供基于接口方法的透明远程过程调用，包括多协议支持，以及软负载均衡，失败容错，地址路由，动态配置等集群支持。
3. 自动发现: 基于注册中心目录服务，使服务消费方能动态的查找服务提供方，使地址透明，使服务提供方可以平滑增加或减少机器。
1.透明化的远程方法调用，就像调用本地方法一样调用远程方法，只需简单配置，没有任何API侵入。
2.软负载均衡及容错机制，可在内网替代F5等硬件负载均衡器，降低成本，减少单点。
3. 服务自动注册与发现，不再需要写死服务提供方地址，注册中心基于接口名查询服务提供者的IP地址，并且能够平滑添加或删除服务提供者。
Dubbo采用全Spring配置方式，透明化接入应用，对应用没有任何API侵入，只需用Spring加载Dubbo的配置即可，Dubbo基于Spring的Schema扩展进行加载。
具体文档可参考阿里官网：http://dubbo.io/Home-zh.htm
另外附上测试demo:
1.新建maven工程：dubbo,作为服务的提供者
依赖jar:
<properties> <jersey.version>2.22.1</jersey.version> <spring.version>4.1.6.RELEASE</spring.version> <dubbo.version>2.5.3</dubbo.version> <zookeeper.version>3.4.6</zookeeper.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.glassfish.jersey.ext</groupId> <artifactId>jersey-spring3</artifactId> <version>${jersey.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.media</groupId> <artifactId>jersey-media-json-jackson</artifactId> <version>${jersey.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.ext</groupId> <artifactId>jersey-mvc</artifactId> <version>${jersey.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-client</artifactId> <version>${jersey.version}</version> </dependency> <!--servlet--> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.7</version> </dependency> <!-- Druid --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.13</version> </dependency> <!-- spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</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-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>${spring.version}</version> </dependency> <!-- MySQL Driver --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.6</version> </dependency> <!-- MyBatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.3.0</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.3</version> </dependency> <!-- Alibaba --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.7</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>org.apache.zookeeper</groupId> <artifactId>zookeeper</artifactId> <version>${zookeeper.version}</version> </dependency> <dependency> <groupId>com.github.sgroschupf</groupId> <artifactId>zkclient</artifactId> <version>0.1</version> </dependency>
web.xml:
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value> classpath:spring-dubbo.xml </param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
spring-dubbo.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:aop="http://www.springframework.org/schema/aop" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd"> <!-- 具体的实现bean --> <bean id="helloDaoImpl" class="com.xwolf.dubbo.dao.impl.HelloDaoImpl"></bean> <dubbo:application name="helloProvider" /> <!-- 使用zookeeper注册中心暴露服务地址 --> <dubbo:registry address="zookeeper://127.0.0.1:2181" /> <!-- 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.xwolf.dubbo.dao.HelloDao" ref="helloDaoImpl" /> </beans>
接口和实现类：
package com.xwolf.dubbo.dao; public interface HelloDao { String sayHello(String name); }
package com.xwolf.dubbo.dao.impl; import com.xwolf.dubbo.dao.HelloDao; public class HelloDaoImpl implements HelloDao { public String sayHello(String name) { return "Hello,"+name+" Dubbo 欢迎你!"; } }
将工程部署即可，服务提供者创建完成。
2.服务调用
新建java Project ,导入jar。
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:aop="http://www.springframework.org/schema/aop" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd"> <dubbo:application name="helloConsumer" /> <!-- 使用zookeeper注册中心暴露服务地址 --> <dubbo:registry address="zookeeper://163.156.12.17:2181" /> <dubbo:reference interface="com.xwolf.dubbo.dao.HelloDao" id="helloDao"/> </beans>
测试接口：
package com.xwolf.dubbo.dao; public interface HelloDao { String sayHello(String name); }
测试：
package com.xwolf.dubbo.test; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.xwolf.dubbo.dao.HelloDao; public class TestDubbo { public static void main(String[] args) { ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext( new String[] { "spring-dubbo-consumer.xml" }); context.start(); HelloDao helloDao = (HelloDao) context.getBean("helloDao"); System.out.println(helloDao.sayHello("wo cao")); } }
运行：
注意问题：
工程中暴露的接口路径和名称一定要完全一致，否则会抛出异常。