在Spring项目中集成使用dubbo实现分布式服务

一、配置启动Zookeeper

ZooKeeper是一个分布式的，开放源码的分布式应用程序协调服务，是Google的Chubby一个开源的实现，是Hadoop和Hbase的重要组件。它是一个为分布式应用提供一致性服务的软件，提供的功能包括：配置维护、域名服务、分布式同步、组服务等。

下载

http://www-eu.apache.org/dist/zookeeper/

配置

Zookeeper安装目录的conf文件夹下的zoo.cfg文件

# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just
# example sakes.
dataDir=C:\zookeeper
# the port at which the clients will connect
clientPort=2181
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=60
#
# Be sure to read the maintenance section of the
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance #
# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

启动

cd C:\zookeeper-3.4.9\bin
zkServer.cmd

二、服务提供端

pom.xml

添加依赖jar包

<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>0.4</version>
</dependency>

java接口和实现类

接口

public interface Test {
String haha(String name);
}

实现类

public class TestImpl implements Test {
@Override
public String haha(String name) {
return "sucesss!"+name;
}
}

spring配置文件

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://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"> <!-- 提供方应用信息，用于计算依赖关系 -->
<dubbo:application name="dubbo-service" />

<!-- 使用multicast广播注册中心暴露服务地址 -->
<!-- <dubbo:registry address="multicast://224.5.6.7:1234" /> -->

<!-- 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.xyh.service.Test"
ref="demoService" />

<!-- 和本地bean一样实现服务 -->
<bean id="demoService" class="com.xyh.service.impl.TestImpl" />
</beans>

web.xml

<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:dubbo-provider.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

三、客户端

pom.xml

添加依赖jar包

<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>0.4</version>
</dependency>

spring配置文件

<?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"> <!-- 提供方应用信息，用于计算依赖关系 -->
<dubbo:application name="dubbo-service-consumer" />

<!-- 使用multicast广播注册中心暴露服务地址 -->
<!-- <dubbo:registry address="multicast://224.5.6.7:1234" /> -->

<!-- 使用zookeeper注册中心暴露服务地址 -->
<dubbo:registry address="zookeeper://127.0.0.1:2181" />

<!-- 声明需要暴露的服务接口 -->
<dubbo:reference id="demoService" interface="com.xyh.service.Test"/>
</beans>

java调用服务

public class Main {
public static void main(String[] args) {
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("dubbo-consumer.xml");
Test test = (Test) applicationContext.getBean("demoService");
System.out.println(test.haha("xyh"));

}
}

四、服务提供端实现分布式

spring配置文件（服务端1）

<!-- 用dubbo协议在20880端口暴露服务 -->
<dubbo:protocol name="dubbo" port="20880" />

实现类

public class TestImpl implements Test {
@Override
public String haha(String name) {
return "sucesss1!"+name;
}
}

spring配置文件（服务端2）

<!-- 用dubbo协议在20881端口暴露服务 -->
<dubbo:protocol name="dubbo" port="20881" />

实现类

public class TestImpl implements Test {
@Override
public String haha(String name) {
return "sucesss2!"+name;
}
}

spring配置文件（服务端3）

<!-- 用dubbo协议在20882端口暴露服务 -->
<dubbo:protocol name="dubbo" port="20882" />

实现类

public class TestImpl implements Test {
@Override
public String haha(String name) {
return "sucesss3!"+name;
}
}

客户端多次调用会输出sucesss1、sucesss2、sucesss3等不一样的结果，这里能看出来zookeeper服务为我们实现了负载均衡，相比hession实现分布式需要自配负载均衡服务器，这是一大优点，省事。