Dubbo框架
今天做了下阿里做的分布式框架Dubbo的实验
我理解的这个框架主要是将controller层和service层分开部署
分为消费者,注册服务器,提供者
面向接口
提供者提供接口的实现方法,并将其注册到zookeeper,消费者只需要引入接口的依赖,可以从zookeeper上远程获取实现类的方法
以下为简单的实验
建立interface工程
这是User类
package com.study.model;
import java.io.Serializable;
public class User implements Serializable {
private Integer id;
private String name;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
这是UserService接口
package com.study.service;
import com.study.model.User;
public interface UserService {
public User queryById(int id);
}
pom.xml文件
build标签中编译插件是为了将interface工程打成jag包并放入本地Maven仓库
<?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>com.studyDubbo</groupId>
<artifactId>dubbo-interface</artifactId>
<version>1.0-SNAPSHOT</version>
<!-- <packaging>war</packaging>-->
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
打包成jar包,package->install,查看本地库,成功安装jar包
提供者
pom.xml
提供者中引入了上面的interface模块,以模拟不同的服务器
<?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>org.example</groupId>
<artifactId>dubbo-provider</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<!--spring依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.3.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.1</version>
</dependency>
<!--Dubbo依赖-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.6.2</version>
</dependency>
<!--引入interface工程-->
<dependency>
<groupId>com.studyDubbo</groupId>
<artifactId>dubbo-interface</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!--zookeeper依赖-->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>4.1.0</version>
</dependency>
</dependencies>
</project>
UserServiceImpl类,实现了interface包中的UserService接口
此外,UserService可以有很多个实现类,只需要在dubbo配置文件中为每个service接口指定版本,消费者就可以根据版本号调用一个接口的不同的实现类
package com.study.service;
import com.study.model.User;
public class UserServiceImpl implements UserService{
@Override
public User queryById(int i) {
User user=new User();
user.setId(i);
user.setName("user_"+i);
return user;
}
}
dubbo配置 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">
<!--声明dubbo服务提供者的名称,保证唯一性-->
<dubbo:application name="dubbo-service" />
<!--声明dubbo使用的协议名称和端口号-->
<dubbo:protocol name="dubbo" port="20880" />
<!--使用zookeeper注册中心 指定注册中心的地址和端口号-->
<dubbo:registry address="zookeeper://localhost:2181" />
<!--暴露服务器接口-->
<dubbo:service interface="com.study.service.UserService" ref="userServiceImpl" />
<!--加载接口实现类-->
<bean id="userServiceImpl" class="com.study.service.UserServiceImpl"/>
</beans>
web.xml配置,只需设置监听器
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<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>
</web-app>
消费者
UserController类
这里用Resource自动装配(所以引入了javax.annotation-api),用autowired会失败,具体原因还有待深究
package com.study.controller;
import com.study.model.User;
import com.study.service.UserService;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.annotation.Resource;
@Controller
public class UserController {
@Resource
private UserService userService;
@RequestMapping("/userDetail")
public String userDetail(Model model,Integer id){
User user1 = userService.queryById(id);
model.addAttribute("user1",user1);
return "userDetail";
}
}
applicationContext.xml
这里没什么说的
<?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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.study.controller"/>
<mvc:annotation-driven />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
dubbo配置文件dubbo-consumer.xml
可以根据dubbo:reference里的version同时配置一个接口的多个实现类
<?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">
<!--声明dubbo服务消费者名称-->
<dubbo:application name="dubbo-consumer"/>
<!--指定注册中心-->
<dubbo:registry address="zookeeper://localhost:2181"/>
<!--引用远程接口服务-->
<dubbo:reference id="userService" interface="com.study.service.UserService"/>
</beans>
web.xml
这里无意间发现有个注意的点
“-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN”
“http://java.sun.com/dtd/web-app_2_3.dtd” >
Servlet2.3/jsp1.2不支持el表达式,然后导致jsp里面没有读出el表达式
解决方案,换个高点的servlet版本即可
或者在jsp页面声明时<%@ page contentType=“text/html;charset=UTF-8” language=“java”
isELIgnored=“false” %>
加入isELIgnored=“false”
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:dubbo-consumer.xml,classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
pom.xml
<?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>org.study.interface</groupId>
<artifactId>dubbo-consumer</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<!--spring依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.3.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.1</version>
</dependency>
<!--Dubbo依赖-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.6.2</version>
</dependency>
<!--引入interface工程-->
<dependency>
<groupId>com.studyDubbo</groupId>
<artifactId>dubbo-interface</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!--zookeeper依赖-->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>4.1.0</version>
</dependency>
<!--resource注解-->
<dependency>
<groupId>javax.annotation</groupId>
<artifactId>javax.annotation-api</artifactId>
<version>1.3.2</version>
</dependency>
</dependencies>
</project>
userDetail.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div>
id:${user1.id}
name:${user1.name}
</div>
</body>
</html>
最后进行测试。先启动zookeeper注册中心,再启动提供者,最后启动消费者,由于我是在一台电脑上面部署运行的,所以提供者和消费者的tomcat服务器端口号记得设置成不同的。最后浏览器访问消费者的url,成功显示了user1的信息。