Dubbo概述

来源：互联网发布：淮南大数据展示中心编辑：程序博客网时间：2024/06/04 18:38

Dubbo是阿里巴巴SOA服务化治理方案的核心框架，每天为2,000+个服务提供3,000,000,000+次访问量支持，并被广泛应用于阿里巴巴集团的各成员站点：

自开源后，已有不少非阿里系公司在使用Dubbo，参见：已知用户

那么，Dubbo是什么？

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。

其核心部分包含:

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。
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。
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。

Dubbo能做什么？

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。
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。
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。

快速启动

(+) (#)

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。

如果不想使用Spring配置，而希望通过API的方式进行调用（不推荐），请参见：API配置 (+)

服务提供者

(#)

完整安装步骤，请参见：示例提供者安装 (+)

定义服务接口: (该接口需单独打包，在服务提供方和消费方共享)

DemoService.java

packagecom.alibaba.dubbo.demo;
 
publicinterface DemoService {
 
    String sayHello(String name);
 
}

在服务提供方实现接口：(对服务消费方隐藏实现)

DemoServiceImpl.java

packagecom.alibaba.dubbo.demo.provider;
 
importcom.alibaba.dubbo.demo.DemoService;
 
publicclass DemoServiceImpl implementsDemoService {
 
    publicString sayHello(String name) {
        return"Hello " + name;
    }
 
}

用Spring配置声明暴露服务：

provider.xml

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="<a href="http://www.springframework.org/schema/beans" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://www.springframework.org/schema/beans"
    xmlns:xsi="<a href="http://www.w3.org/2001/XMLSchema-instance" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://www.w3.org/2001/XMLSchema-instance"
    xmlns:dubbo="<a href="http://code.alibabatech.com/schema/dubbo" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">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        <a href="http://code.alibabatech.com/schema/dubbo/dubbo.xsd" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
 
    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:applicationname="hello-world-app" />
 
    <!-- 使用multicast广播注册中心暴露服务地址 -->
    <dubbo:registryaddress="multicast://224.5.6.7:1234"/>
 
    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocolname="dubbo"port="20880"/>
 
    <!-- 声明需要暴露的服务接口 -->
    <dubbo:serviceinterface="com.alibaba.dubbo.demo.DemoService"ref="demoService"/>
 
    <!-- 和本地bean一样实现服务 -->
    <beanid="demoService"class="com.alibaba.dubbo.demo.provider.DemoServiceImpl"/>
 
</beans>

加载Spring配置：

Provider.java

importorg.springframework.context.support.ClassPathXmlApplicationContext;
 
publicclass Provider {
 
    publicstatic void main(String[] args) throwsException {
        ClassPathXmlApplicationContext context = newClassPathXmlApplicationContext(newString[] {"<a href="http://dubbo.io/provider.xml" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://dubbo.io/provider.xml"});
        context.start();
 
        System.in.read();// 按任意键退出
    }
 
}

服务消费者

(#)

完整安装步骤，请参见：示例消费者安装 (+)

通过Spring配置引用远程服务：

consumer.xml

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="<a href="http://www.springframework.org/schema/beans" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://www.springframework.org/schema/beans"
    xmlns:xsi="<a href="http://www.w3.org/2001/XMLSchema-instance" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://www.w3.org/2001/XMLSchema-instance"
    xmlns:dubbo="<a href="http://code.alibabatech.com/schema/dubbo" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">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        <a href="http://code.alibabatech.com/schema/dubbo/dubbo.xsd" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
 
    <!-- 消费方应用名，用于计算依赖关系，不是匹配条件，不要与提供方一样 -->
    <dubbo:applicationname="consumer-of-helloworld-app" />
 
    <!-- 使用multicast广播注册中心暴露发现服务地址 -->
    <dubbo:registryaddress="multicast://224.5.6.7:1234"/>
 
    <!-- 生成远程服务代理，可以和本地bean一样使用demoService -->
    <dubbo:referenceid="demoService"interface="com.alibaba.dubbo.demo.DemoService"/>
 
</beans>

加载Spring配置，并调用远程服务：(也可以使用IoC注入)

Consumer.java

importorg.springframework.context.support.ClassPathXmlApplicationContext;
importcom.alibaba.dubbo.demo.DemoService;
 
publicclass Consumer {
 
    publicstatic void main(String[] args) throwsException {
        ClassPathXmlApplicationContext context = newClassPathXmlApplicationContext(newString[] {"<a href="http://dubbo.io/consumer.xml" "="" style="outline: none; text-decoration: none; border-top-left-radius: 0px !important; border-top-right-radius: 0px !important; border-bottom-right-radius: 0px !important; border-bottom-left-radius: 0px !important; background-image: none !important; border: 0px !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; line-height: 1.2em !important; margin: 0px !important; overflow: visible !important; padding: 0px !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; width: auto !important; box-sizing: content-box !important; font-size: 1em !important; min-height: inherit !important; color: rgb(0, 51, 102) !important;">http://dubbo.io/consumer.xml"});
        context.start();
 
        DemoService 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
    }
 
}

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