一、dubbo 服务化最佳实践
1. 分包
建议将服务接口、服务模型、服务异常等均放在公共包中
2. 粒度
服务接口尽可能大粒度,每个服务方法应代表一个功能,而不是某功能的一个步骤,否则将面临分布式事务问题,Dubbo 暂未提供分布式事务支持
服务接口建议以业务场景为单位划分,并对相近业务做抽象,防止接口数量爆炸
不建议使用过于抽象的通用接口,如:Map query(Map),这样的接口没有明确语义,会给后期维护带来不便
3. 版本
每个接口都应定义版本号,为后续不兼容升级提供可能,如: <dubbo:service interface="com.xxx.XxxService" version="1.0" />。
建议使用两位版本号,要变更服务版本。先升级一半提供者为新版本,再将消费者全部升为新版本,然后将剩下的一半提供者升为新版本
二、改造 dubbo 项目
抽象分散在多个项目中的公共接口,实体类,异常,工具类到一个项目中(比如:link-interface)
在其他项目如服务提供者,消费者共用公共的资源
三、link-interface
link-interface是一个maven Java工程
dubbo官方推荐使用的一个模式,将实体bean和业务接口存放到接口工程中
1. pom.xml
这只是一个java工程,这里不用改变
<?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.md.dubbo</groupId> <artifactId>03-link-interface</artifactId> <version>1.0.0</version> </project>
@H_502_103@2. 实体类
package com.md.dubbo.model; import java.io.Serializable; /** * @author MD * @create 2020-08-19 10:40 */ // 对于分布式开发,对象要进行序列化操作 public class User implements Serializable { private Integer id; private String username; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } }
@H_502_103@3. 公共接口
package com.md.dubbo.service; import com.md.dubbo.model.User; /** * @author MD * @create 2020-08-19 10:41 */ public interface UserService { /** * 通过用户id获取用户信息 * @param id * @return */ User queryUserById(Integer id); /** * 获取用户总人数 * @return */ Integer queryAllUserCount(); }
@H_502_103@四、提供者
建立maven web工程
1. pom.xml
注意引入接口工程的依赖
<?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.md.dubbo</groupId> <artifactId>04-link-userservice-provider</artifactId> <version>1.0.0</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> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <!--spring依赖--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.16.RELEASE</version> </dependency> <!--dubbo依赖--> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.6.2</version> </dependency> <!--引入接口工程--> <dependency> <groupId>com.md.dubbo</groupId> <artifactId>03-link-interface</artifactId> <version>1.0.0</version> </dependency> </dependencies> <build> </build> </project>
@H_502_103@2. 接口实现
这里只是一个简单的模拟
package com.md.dubbo.service.impl; import com.md.dubbo.model.User; import com.md.dubbo.service.UserService; /** * @author MD * @create 2020-08-19 10:48 */ public class UserServiceImpl implements UserService { @Override public User queryUserById(Integer id) { User user = new User(); user.setId(id); user.setUsername("山丘!"); return user; } @Override public Integer queryAllUserCount() { return 9; } }
@H_502_103@3. 服务提供者的核心配置文件
在resources目录下建立dubbo-userservice-provider.xml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://dubbo.apache.org/schema/dubbo" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd"> <!--声明dubbo服务提供者名称:保证唯一性,通常用model名就可以--> <dubbo:application name="04-link-userservice-provider"/> <!--设置dubbo使用的协议和端口号--> <dubbo:protocol name="dubbo" port="20880"/> <!--暴露服务接口--> <dubbo:service interface="com.md.dubbo.service.UserService" ref="userService" registry="N/A"/> <!--加载业务接口的实现类到spring容器中--> <bean id="userService" class="com.md.dubbo.service.impl.UserServiceImpl"/> </beans>
@H_502_103@4. 添加监听器
在web.xml中
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <!--默认的版本低的话换成这个版本的,直接复制即可--> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:dubbo-userservice-provider.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> </web-app>
@H_502_103@5. 配置Tomcat
端口号注意修改一下:避免冲突
HTTP port :8081
JMX port:1098
五、消费者
1. pom.xml
还是maven web项目
注意:添加了接口的依赖
<?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.md.dubbo</groupId> <artifactId>05-link-consumer</artifactId> <version>1.0.0</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> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <!--spring依赖--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.16.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.16.RELEASE</version> </dependency> <!--dubbo依赖--> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.6.2</version> </dependency> <!--接口工程--> <!--此时不像之前的还得打jar包,这里不用,03是普通的java工程,只提供接口--> <dependency> <groupId>com.md.dubbo</groupId> <artifactId>03-link-interface</artifactId> <version>1.0.0</version> </dependency> </dependencies> <build> </build> </project>
@H_502_103@2. 服务消费者的核心配置文件
在resources目录下建立dubbo-consumer.xml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://dubbo.apache.org/schema/dubbo" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd"> <!--声明服务消费着名称:唯一--> <dubbo:application name="05-link-consumer"/> <!--引用远程接口服务--> <dubbo:reference id="userService" interface="com.md.dubbo.service.UserService" url="dubbo://localhost:20880" registry="N/A"/> </beans>
@H_502_103@3. controller
package com.md.dubbo.web; import com.md.dubbo.model.User; import com.md.dubbo.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; /** * @author MD * @create 2020-08-19 11:11 */ @Controller public class UserController { @Autowired private UserService userService; @RequestMapping(value = "/userDetail") public String userDetail(Model model,Integer id){ // 根据id获取用户信息 User user = userService.queryUserById(id); // 获取用户总人数 Integer allUserCount = userService.queryAllUserCount(); model.addAttribute("user",user); model.addAttribute("allUserCount",allUserCount); return "userDetail"; } }
@H_502_103@4. applicationContext.xml
在resources目录下创建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: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 http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!--扫描组件--> <context:component-scan base-package="com.md.dubbo.web"/> <!--配置注解驱动--> <mvc:annotation-driven/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
@H_502_103@5. 配置中央调度器
在web.xml中
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <!--中央调度器--> <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,classpath:dubbo-consumer.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
@H_502_103@6. 配置Tomcat
此时使用默认的就可以了
7. 配置测试页面
在webapp下 建立userDetail.jsp
<%-- Created by IntelliJ IDEA. User: MD Date: 2020/8/19 Time: 11:16 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h1>hello Dubbo</h1> <h2>用户id:${user.id}</h2> <h2>用户姓名:${user.username}</h2> <h2>用户总数:${allUserCount}</h2> </body> </html>
@H_502_103@8. 测试
- 首先开服务提供者的Tomcat
- 然后开服务消费者的Tomcat
- 然后在地址栏输入,就可以看到了