[原]Dubbo实例
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。主要核心部件
Remoting: 网络通信框架,实现了sync-over-async 和 request-response 消息机制.
RPC: 一个远程过程调用的抽象,支持负载均衡、容灾和集群功能
Registry: 服务目录框架用于服务的注册和服务事件发布和订阅。
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。
dubbo架构图如下所示:
节点角色说明:
Provider: 暴露服务的服务提供方。
Consumer: 调用远程服务的服务消费方。
Registry: 服务注册与发现的注册中心。
Monitor: 统计服务的调用次调和调用时间的监控中心。
Container: 服务运行容器。
调用关系说明:
0 服务容器负责启动,加载,运行服务提供者。
1. 服务提供者在启动时,向注册中心注册自己提供的服务。
2. 服务消费者在启动时,向注册中心订阅自己所需的服务。
3. 注册中心返回服务提供者地址列表给消费者,如果有变更,注册中心将基于长连接推送变更数据给消费者。
4. 服务消费者,从提供者地址列表中,基于软负载均衡算法,选一台提供者进行调用,如果调用失败,再选另一台调用。
5. 服务消费者和提供者,在内存中累计调用次数和调用时间,定时每分钟发送一次统计数据到监控中心。
2. 实例
2.1 pom.xml
首先maven项目增加dubbo的jar依赖,因为要用到zookeeper注册中心,也要依赖但是要去掉自带的log4j。
<?xml version="1.0" encoding="UTF-8"?> <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>test</groupId> <artifactId>test</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <spring.version>3.1.4.RELEASE</spring.version> <slf4j.version>1.6.6</slf4j.version> </properties> <dependencies> <!-- dubbo --> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.5.3</version> </dependency> <!-- zookeeper --> <dependency> <groupId>org.apache.zookeeper</groupId> <artifactId>zookeeper</artifactId> <version>3.4.6</version> <exclusions> <exclusion> <groupId>log4j</groupId> <artifactId>log4j</artifactId> </exclusion> </exclusions> </dependency> <!-- Spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-asm</artifactId> <version>${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-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-expression</artifactId> <version>${spring.version}</version> </dependency> <!-- log --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency> </dependencies> </project>
因为要增加zookeeper的注册管理,所以如果有可用的zookeeper就用可用的zookeeper。本实例使用的zk地址是192.168.4.114:2181
2.2
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 = "hello-world-app-provider" /> <!--zookeeper注册中心 --> <dubbo:registry protocol="zookeeper" address="192.168.4.114:2181" /> <!-- 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.mt.test.DemoService" ref="demoProvideService"/> <!-- 具体的实现bean --> <bean id="demoProvideService" class="com.mt.test.DemoServiceImpl" /> </beans>
<?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"> <!-- 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:application name="hello-world-app-consumer"/> <!-- 使用zookeeper注册中心暴露服务地址 --> <dubbo:registry protocol="zookeeper" address="192.168.4.114:2181"/> <!-- 生成远程服务代理,可以和本地bean一样使用demoService --> <dubbo:reference id="demoConsumeService" interface="com.mt.test.DemoService"/> </beans>
2.4 DemoService.java
package com.mt.test; import java.util.List; public interface DemoService { public String sayHello(String name); public List getUsers(); }
package com.mt.test; import java.util.ArrayList; import java.util.List; public class DemoServiceImpl implements DemoService{ @Override public String sayHello(String name) { return "Hello " + name; } @Override public List getUsers() { List list = new ArrayList(); User u1 = new User(); u1.setName("jack"); u1.setAge(20); u1.setSex("男"); User u2 = new User(); u2.setName("tom"); u2.setAge(21); u2.setSex("女"); User u3 = new User(); u3.setName("rose"); u3.setAge(19); u3.setSex("女"); list.add(u1); list.add(u2); list.add(u3); return list; } }
2.6 LuncherProvider.java
package com.mt.test; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.context.ApplicationContext; public class LuncherProvider { public static void main(String[] args) throws Exception { LuncherProvider luncher = new LuncherProvider(); luncher.start(); System.in.read(); // 为保证服务一直开着,利用输入流的阻塞来模拟 } public void start() { String configLocation = "spring/dubbo-provider.xml"; ApplicationContext context = new ClassPathXmlApplicationContext(configLocation); String[] names = context.getBeanDefinitionNames(); System.out.print("Beans:"); for (String string : names) System.out.print(string + ","); System.out.println(); } }
2.7 LuncherConsumer.java
package com.mt.test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class LuncherConsumer { public static void main(String[] args) throws Exception { LuncherConsumer luncher = new LuncherConsumer(); luncher.start(); } void start() { String configLocation = "spring/dubbo-consumer.xml"; ApplicationContext context = new ClassPathXmlApplicationContext(configLocation); String[] names = context.getBeanDefinitionNames(); System.out.print("Beans:"); for (String string : names) { System.out.print(string); System.out.print(","); } System.out.println(); DemoService ds = (DemoService) context.getBean("demoConsumeService"); System.out.println(ds.sayHello("hehe")); System.out.println(ds.getUsers()); } }
2.8 User.java
package com.mt.test; import java.io.Serializable; //必须实现Serializable接口 public class User implements Serializable { private static final long serialVersionUID = -2814022769568306965L; private String name; private Integer age; private String sex; public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } @Override public String toString() { return "User{" + "name='" + name + '\'' + ", age=" + age + ", sex='" + sex + '\'' + '}'; } }<strong> </strong>
运行结果:
(1)provider:
Beans:hello-world-app-provider,com.alibaba.dubbo.config.RegistryConfig,dubbo,com.mt.test.DemoService,demoProvideService,
(2)consumer:
Beans:hello-world-app-consumer,com.alibaba.dubbo.config.RegistryConfig,demoConsumeService,
Hello hehe
[User{name='jack', age=20, sex='男'}, User{name='tom', age=21, sex='女'}, User{name='rose', age=19, sex='女'}]