dubbo入门（1）

dubbo是什么：
1. 负载均衡是对外提供一个公共地址，请求过来时通过轮询、随机等，路由到不同server。目的分摊压力。
失效备援是发现一台server挂了，就让另外一台去服务了。跟餐馆换个服务员继续招待你一样。

1. Java下的一套RPC框架(soa思想)，作用就是统一管理配置，各个系统服务间的调用。dubbo在淘宝也是解决他们实际问题的，不一定适合其他。 另外各家公司也都有大同小异的实现，所以没多少人用、也就没多少介绍。
   原理就是： A系统调用B系统接口服务， 后面就是怎么把这个流程，动态化(zookeeper通知)、权限化、配置化、低耦合化、自动化。

package com.dubbo.test;

public interface BankService {
    public String getBinkinfo();
}

package com.dubbo.test;

import com.alibaba.dubbo.config.annotation.Service;

@Service(protocol = {"dubbo"}, timeout = 3000)
public class BankServiceImpl implements BankService{

    @Override
    public String getBinkinfo() {

        return "icbc";
    }

}

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">

    <dubbo:application name="bankServiceProvider"/>

    <dubbo:registry address="zookeeper://192.168.1.50:2182" register="true"/>

    <!-- 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.dubbo.test.BankService" ref="bankService" />

    <bean id="bankService" class="com.dubbo.test.BankServiceImpl" />
</beans>

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: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">

    <dubbo:application name="bankServiceConsumer"/>

    <dubbo:registry address="zookeeper://192.168.1.50:2182" register="true"/>

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

    <dubbo:reference id="bankService" interface="com.dubbo.test.BankService" />
</beans>

package dubbotest.d1;

import java.io.IOException;

import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * dubbo提供者
 * title: ProviderTest.java
 * description: 
 * @author lulei
 * @created 2016年12月29日 上午10:20:24
 */
public class ProviderTest {

    @Test
    public void test1() throws IOException {
         ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"provider.xml"});
         context.start();
         System.in.read(); // 按任意键退出

    }


}

package dubbotest.d1;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.dubbo.test.BankService;

public class ConsumerTest {
    public static void main(String[] args) {
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"consumer.xml"});
            context.start();

            BankService bankService = (BankService)context.getBean("bankService"); // 获取远程服务代理
            String hello = bankService.getBinkinfo(); // 执行远程方法

            System.out.println( hello ); // 显示调用结果
    }
}

pom.xml:

<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>dubbotest</groupId>
    <artifactId>d1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <!-- <packaging>jar</packaging> -->

    <name>d1</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!-- dubbo -->
        <dependency>
            <groupId>dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.8.4</version>
        </dependency>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.18.1-GA</version>
        </dependency>
        <!-- <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty</artifactId>
             <version>3.7.1.Final</version>
        </dependency> -->
        <!--spring相关 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.0.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>4.0.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.0.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.6</version>
        </dependency>

      <dependency>
         <groupId>com.github.sgroschupf</groupId>
         <artifactId>zkclient</artifactId>
         <version>0.1</version>
      </dependency>
        <!-- <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> 
            </dependency> -->

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

    </dependencies>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.1</version>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
            </configuration>
        </plugin>
    </plugins>
</project>