Dubbo的学习与总结（二）- -使用Dubbo

在上一篇中，我们对Dubbo有了一个大概的认识，现在我们来说如何使用。Dubbo的服务发现和使用是基于注册中心的，推荐使用zookeeper作为注册中心，注册中心的安装参考：http://blog.csdn.net/lf_214/article/details/50998910
Dubbo是一个面向服务的治理方案，那首先我们要有服务，还要定义出服务之间的规范，说到规范，我们就想到了Java中的接口，接口就是我们提供的规范。不论是服务调用方还是服务使用方，都要依照这个规范来使用。所以，规范应该是独立的。我们以用户服务为例，采用Maven来构建一个项目。

1.项目结构：

d-parent
d-facade
d-provider
d-client

2.父pom.xml文件

<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.ums</groupId>
<artifactId>d-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>

<name>d-parent</name>
<url>http://maven.apache.org</url>

<modules>
<module>../d-client</module>
<module>../d-facade</module>
<module>../d-provider</module>
</modules>

<properties>
<!-- jar包版本 -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<jdk.version>1.6</jdk.version>
</properties>

<dependencyManagement>
<dependencies>
<!-- spring依赖包 -->
<!-- 支持springaop -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>3.2.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>3.2.8.RELEASE</version>
</dependency>

<!-- 日志依赖包 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.10</version>
</dependency>
<!-- logback start -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>1.7.10</version>
</dependency>
<!-- logback end -->

<!-- dubbo start -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
<exclusions>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- dubbo end -->

<!-- dubbo 支持Zookeeper 用于分布式服务管理 -->
<dependency>
<groupId>com.github.sgroschupf</groupId>
<artifactId>zkclient</artifactId>
<version>0.1</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.6</version>
</dependency>
<!-- dubbo 支持Zookeeper end -->
<!-- dubbo 内置服务 -->
<dependency>
<groupId>org.jboss.netty</groupId>
<artifactId>netty</artifactId>
<version>3.2.5.Final</version>
</dependency>
<!-- dubbo 内置服务 -->

<!-- 单元测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>

</dependencies>
</dependencyManagement>

<build>
<finalName>${project.artifactId}</finalName>
<resources>
<resource>
<targetPath>${project.build.directory}/classes</targetPath>
<directory>src/main/resources</directory>
<filtering>true</filtering>
<includes>
<include>**/*.xml</include>
<include>**/*.properties</include>
</includes>
</resource>

</resources>
<testResources>
<testResource>
<directory>src/test/resources</directory>
<filtering>true</filtering>
</testResource>
</testResources>
<plugins>
<!-- 资源文件拷贝插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.7</version>
<configuration>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
<!-- java编译插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<!-- 配置Tomcat插件 -->
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>

package com.ums.facade;

import com.ums.dto.UserRequest;
import com.ums.dto.UserResponse;

public interface IUserQueryFacade {

public UserResponse queryUser(UserRequest userRequest);

public UserResponse queryAllUser();
}

package com.ums.dto;

import java.io.Serializable;

public class UserRequest implements Serializable{

/**
* @Fields serialVersionUID : TODO(用一句话描述这个变量表示什么)
*/
private static final long serialVersionUID = -8315084174735728065L;

private String userId;

public String getUserId() {
return userId;
}

public void setUserId(String userId) {
this.userId = userId;
}

@Override
public String toString() {
return "UserRequest [userId=" + userId + "]";
}

}

package com.ums.dto;

import java.io.Serializable;

public class UserResponse implements Serializable{

/**
* @Fields serialVersionUID : TODO(用一句话描述这个变量表示什么)
*/
private static final long serialVersionUID = 1148480200357449237L;

private String code;

private String msg;

public void setCode(String code){
this.code = code;
}

public String getCode(){
return code;
}

public void setMsg(String msg){
this.msg = msg;
}

public String getMsg(){
return msg;
}

@Override
public String toString() {
return "UserResponse 
";
}

}


4.按照规范编写服务

[code]package com.ums.facade.impl;

import org.springframework.stereotype.Service;

import com.ums.dto.UserRequest;
import com.ums.dto.UserResponse;
import com.ums.facade.IUserQueryFacade;

@Service("userQuery")
public class UserQueryFacadeImpl implements IUserQueryFacade{

public UserResponse queryUser(UserRequest userRequest) {
UserResponse userResponse = new UserResponse();
String userId = userRequest.getUserId();
System.out.println("查询用户userId:"+userId);
userResponse.setCode("000");
userResponse.setMsg("成功");
return userResponse;
}

public UserResponse queryAllUser() {
UserResponse userResponse = new UserResponse();
userResponse.setCode("000");
userResponse.setMsg("成功");
return userResponse;
}
}

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:task="http://www.springframework.org/schema/task"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> 
<!-- dubbo 提供服务 -->
<!--  1: 提供服务 名称   不能同名-->
<dubbo:application name="dubbo-provider-ums" logger="slf4j"/>
<!-- 2：向zookeeper集群注册中心注册，集群内用逗号分割，不同注册中心用|分割 -->
<dubbo:registry protocol="zookeeper" address="127.0.0.1:2181"/>

<!-- 3:以dubbo协议提供服务   默认20880 -->
<dubbo:protocol name="dubbo" port="20880"/>

<!-- 当ProtocolConfig和ServiceConfig某属性没有配置时,采用此缺省值 -->
<dubbo:provider timeout="10000" threadpool="fixed" threads="100" accepts="1000" />

<!-- 4:暴露接口给消费方  单位毫秒 -->
<dubbo:service interface="com.ums.facade.IUserQueryFacade" ref="userQuery" protocol="dubbo"/>
</beans>

5.按照规范编写客户端调用

package com.ums.client;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.ums.dto.UserRequest;
import com.ums.dto.UserResponse;
import com.ums.facade.IUserQueryFacade;

/**
* Hello world!
*
*/
public class App
{
public static void main( String[] args )
{
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
IUserQueryFacade userQuery = (IUserQueryFacade) context.getBean("userQuery");

UserRequest userRequest = new UserRequest();
userRequest.setUserId("123");
UserResponse userResponse = userQuery.queryUser(userRequest);
System.out.println("响应结果："+userResponse);
context.close();
}
}

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:task="http://www.springframework.org/schema/task"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> 
<!-- dubbo 提供服务 -->
<!--  1: 服务消费者-->
<dubbo:application name="dubbo-consumer-ums" logger="slf4j"/>
<!-- 2：向注册中心  以广播的形式注册 -->
<dubbo:registry protocol="zookeeper" address="127.0.0.1:2181"/>

<!-- 3:调用服务提供方暴露的接口 -->
<dubbo:reference interface="com.ums.facade.IUserQueryFacade" id="userQuery" check="false"/>
<!-- 全局设置  连接超时时间 单位是毫秒   当前是10分钟   并设置启动时dubbo不检索是否有相对应的服务提供方   仅开发阶段使用  -->
<dubbo:consumer timeout="6000"/>

</beans>

package com.ums.provider;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
* 启动dubbo服务
* @author liufei
* @date 2016-3-28
*/
public class DubboProvider {

private static final Logger log = LoggerFactory.getLogger(DubboProvider.class);

public static void main(String[] args) {
try {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
context.start();
} catch (Exception e) {
log.error("== DubboProvider context start error:",e);
}
synchronized (DubboProvider.class) {
while (true) {
try {
DubboProvider.class.wait();
} catch (InterruptedException e) {
log.error("== synchronized error:",e);
}
}
}
}

}