Dubbo（95）如何在社交网络中应用Dubbo？
在社交网络中应用Dubbo，可以通过以下步骤实现：
- 项目结构设计：规划项目的模块结构，通常包括服务接口模块、各个服务提供者模块（如用户服务、好友服务、消息服务等）、服务消费者模块（如前端应用、后台管理系统等）。
- 服务接口定义：定义各个服务的接口，确保服务提供者和消费者能够共享相同的接口。
- 服务提供者实现：实现各个服务接口，并配置Dubbo提供服务。
- 服务消费者调用：在服务消费者中引用服务接口，并通过Dubbo调用远程服务。
- 服务注册与发现：配置注册中心（如Zookeeper）以实现服务注册与发现。
- 配置管理：管理项目的配置文件，确保服务提供者和消费者能够正确连接到注册中心并发现彼此。
- 测试与部署：测试服务的调用，确保服务能够正常工作，并将服务部署到生产环境。
以下是一个详细的示例，展示如何在社交网络中应用Dubbo。
1. 项目结构设计
我们将创建一个包含多个模块的项目：dubbo-api、user-service、friend-service、message-service 和 frontend-application。
social-network
├── dubbo-api
│ └── src/main/java/com/example/dubbo/api
│ ├── UserService.java
│ ├── FriendService.java
│ └── MessageService.java
├── user-service
│ └── src/main/java/com/example/user
│ ├── service
│ │ └── UserServiceImpl.java
│ ├── config
│ │ └── DubboProviderConfig.java
│ └── UserServiceApplication.java
├── friend-service
│ └── src/main/java/com/example/friend
│ ├── service
│ │ └── FriendServiceImpl.java
│ ├── config
│ │ └── DubboProviderConfig.java
│ └── FriendServiceApplication.java
├── message-service
│ └── src/main/java/com/example/message
│ ├── service
│ │ └── MessageServiceImpl.java
│ ├── config
│ │ └── DubboProviderConfig.java
│ └── MessageServiceApplication.java
├── frontend-application
│ └── src/main/java/com/example/frontend
│ ├── controller
│ │ └── SocialNetworkController.java
│ ├── config
│ │ └── DubboConsumerConfig.java
│ └── FrontendApplication.java
└── pom.xml
2. 服务接口定义
2.1 创建 dubbo-api 模块
创建 dubbo-api 模块的 pom.xml 文件：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/POM/4.0.0 http://www.w3.org/2001/04/xmldsig-more#">
<modelVersion>4.0.0modelVersion>
<groupId>com.examplegroupId>
<artifactId>dubbo-apiartifactId>
<version>1.0-SNAPSHOTversion>
<packaging>jarpackaging>
<dependencies>
<dependency>
<groupId>org.apache.dubbogroupId>
<artifactId>dubboartifactId>
<version>2.7.8version>
dependency>
dependencies>
project>
2.2 定义服务接口
在 dubbo-api/src/main/java/com/example/dubbo/api 目录下创建 UserService、FriendService 和 MessageService 接口：
package com.example.dubbo.api;
public interface UserService {
String getUser(String userId);
}
public interface FriendService {
String addFriend(String userId, String friendId);
String getFriends(String userId);
}
public interface MessageService {
String sendMessage(String fromUserId, String toUserId, String message);
String getMessages(String userId);
}
3. 服务提供者实现
3.1 创建 user-service 模块
创建 user-service 模块的 pom.xml 文件：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/POM/4.0.0 http://www.w3.org/2001/04/xmldsig-more#">
<parent>
<groupId>com.examplegroupId>
<artifactId>social-networkartifactId>
<version>1.0-SNAPSHOTversion>
<relativePath>../pom.xmlrelativePath>
parent>
<artifactId>user-serviceartifactId>
<dependencies>
<dependency>
<groupId>com.examplegroupId>
<artifactId>dubbo-apiartifactId>
<version>1.0-SNAPSHOTversion>
dependency>
<dependency>
<groupId>org.apache.dubbogroupId>
<artifactId>dubbo-spring-boot-starterartifactId>
<version>2.7.8version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starterartifactId>
dependency>
<dependency>
<groupId>ch.qos.logbackgroupId>
<artifactId>logback-classicartifactId>
<version>1.2.3version>
dependency>
dependencies>
project>
3.2 实现用户服务接口
在 user-service/src/main/java/com/example/user/service 目录下创建 UserServiceImpl 类：
package com.example.user.service;
import com.example.dubbo.api.UserService;
import org.apache.dubbo.config.annotation.DubboService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@DubboService
public class UserServiceImpl implements UserService {
private static final Logger logger = LoggerFactory.getLogger(UserServiceImpl.class);
@Override
public String getUser(String userId) {
logger.info("Fetching user with ID: {}", userId);
return "User: " + userId;
}
}
3.3 配置Dubbo服务
在 user-service/src/main/java/com/example/user/config 目录下创建 DubboProviderConfig 类：
package com.example.user.config;
import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.context.annotation.Configuration;
@Configuration
@EnableDubbo(scanBasePackages = "com.example.user.service")
public class DubboProviderConfig {
}
3.4 创建启动类
在 user-service/src/main/java/com/example/user 目录下创建 UserServiceApplication 类：
package com.example.user;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class UserServiceApplication {
public static void main(String[] args) {
SpringApplication.run(UserServiceApplication.class, args);
}
}
3.5 配置文件
在 user-service/src/main/resources 目录下创建 application.yml 配置文件：
spring:
application:
name: user-service
main:
web-application-type: none
dubbo:
application:
name: user-service
registry:
address: zookeeper://localhost:2181
protocol:
name: dubbo
port: 20880
scan:
base-packages: com.example.user.service
logging:
level:
com.example.user: INFO
file:
name: logs/user-service.log
3.6 创建 friend-service 模块
创建 friend-service 模块的 pom.xml 文件，类似于 user-service 模块。
3.7 实现好友服务接口
在 friend-service/src/main/java/com/example/friend/service 目录下创建 FriendServiceImpl 类：
package com.example.friend.service;
import com.example.dubbo.api.FriendService;
import org.apache.dubbo.config.annotation.DubboService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@DubboService
public class FriendServiceImpl implements FriendService {
private static final Logger logger = LoggerFactory.getLogger(FriendServiceImpl.class);
@Override
public String addFriend(String userId, String friendId) {
logger.info("Adding friend {} for user {}", friendId, userId);
return "Friend " + friendId + " added for user " + userId;
}
@Override
public String getFriends(String userId) {
logger.info("Fetching friends for user {}", userId);
return "Friends of user " + userId;
}
}
3.8 配置Dubbo服务和启动类
在 friend-service 模块中配置Dubbo服务和启动类，类似于 user-service 模块。
3.9 创建 message-service 模块
创建 message-service 模块的 pom.xml 文件，类似于 user-service 模块。
3.10 实现消息服务接口
在 message-service/src/main/java/com/example/message/service 目录下创建 MessageServiceImpl 类：
package com.example.message.service;
import com.example.dubbo.api.MessageService;
import org.apache.dubbo.config.annotation.DubboService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@DubboService
public class MessageServiceImpl implements MessageService {
private static final Logger logger = LoggerFactory.getLogger(MessageServiceImpl.class);
@Override
public String sendMessage(String fromUserId, String toUserId, String message) {
logger.info("Sending message from {} to {}: {}", fromUserId, toUserId, message);
return "Message sent from " + fromUserId + " to " + toUserId + ": " + message;
}
@Override
public String getMessages(String userId) {
logger.info("Fetching messages for user {}", userId);
return "Messages for user " + userId;
}
}
3.11 配置Dubbo服务和启动类
在 message-service 模块中配置Dubbo服务和启动类，类似于 user-service 模块。
4. 服务消费者调用
4.1 创建 frontend-application 模块
创建 frontend-application 模块的 pom.xml 文件：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/POM/4.0.0 http://www.w3.org/2001/04/xmldsig-more#">
<parent>
<groupId>com.examplegroupId>
<artifactId>social-networkartifactId>
<version>1.0-SNAPSHOTversion>
<relativePath>../pom.xmlrelativePath>
parent>
<artifactId>frontend-applicationartifactId>
<dependencies>
<dependency>
<groupId>com.examplegroupId>
<artifactId>dubbo-apiartifactId>
<version>1.0-SNAPSHOTversion>
dependency>
<dependency>
<groupId>org.apache.dubbogroupId>
<artifactId>dubbo-spring-boot-starterartifactId>
<version>2.7.8version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>ch.qos.logbackgroupId>
<artifactId>logback-classicartifactId>
<version>1.2.3version>
dependency>
dependencies>
project>
4.2 创建控制器
在 frontend-application/src/main/java/com/example/frontend/controller 目录下创建 SocialNetworkController 类：
package com.example.frontend.controller;
import com.example.dubbo.api.FriendService;
import com.example.dubbo.api.MessageService;
import com.example.dubbo.api.UserService;
import org.apache.dubbo.config.annotation.DubboReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SocialNetworkController {
private static final Logger logger = LoggerFactory.getLogger(SocialNetworkController.class);
@DubboReference
private UserService userService;
@DubboReference
private FriendService friendService;
@DubboReference
private MessageService messageService;
@GetMapping("/getUser")
public String getUser(@RequestParam String userId) {
logger.info("Fetching user with ID: {}", userId);
return userService.getUser(userId);
}
@GetMapping("/addFriend")
public String addFriend(@RequestParam String userId, @RequestParam String friendId) {
logger.info("Adding friend with ID: {} to user with ID: {}", friendId, userId);
return friendService.addFriend(userId, friendId);
}
@GetMapping("/sendMessage")
public String sendMessage(@RequestParam String fromUserId, @RequestParam String toUserId, @RequestParam String message) {
logger.info("Sending message from {} to {}: {}", fromUserId, toUserId, message);
return messageService.sendMessage(fromUserId, toUserId, message);
}
}
4.3 配置Dubbo消费
在 frontend-application/src/main/java/com/example/frontend/config 目录下创建 DubboConsumerConfig 类：
package com.example.frontend.config;
import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.context.annotation.Configuration;
@Configuration
@EnableDubbo(scanBasePackages = "com.example.frontend.controller")
public class DubboConsumerConfig {
}
4.4 创建启动类
在 frontend-application/src/main/java/com/example/frontend 目录下创建 FrontendApplication 类：
package com.example.frontend;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class FrontendApplication {
public static void main(String[] args) {
SpringApplication.run(FrontendApplication.class, args);
}
}
4.5 配置文件
在 frontend-application/src/main/resources 目录下创建 application.yml 配置文件：
spring:
application:
name: frontend-application
dubbo:
application:
name: frontend-application
registry:
address: zookeeper://localhost:2181
protocol:
name: dubbo
scan:
base-packages: com.example.frontend.controller
logging:
level:
com.example.frontend: INFO
file:
name: logs/frontend-application.log
5. 根项目的 pom.xml
在根项目 social-network 中创建 pom.xml 文件，定义模块和依赖管理：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/POM/4.0.0 http://www.w3.org/2001/04/xmldsig-more#">
<modelVersion>4.0.0modelVersion>
<groupId>com.examplegroupId>
<artifactId>social-networkartifactId>
<version>1.0-SNAPSHOTversion>
<packaging>pompackaging>
<modules>
<module>dubbo-apimodule>
<module>user-servicemodule>
<module>friend-servicemodule>
<module>message-servicemodule>
<module>frontend-applicationmodule>
modules>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.dubbogroupId>
<artifactId>dubboartifactId>
<version>2.7.8version>
dependency>
<dependency>
<groupId>org.apache.dubbogroupId>
<artifactId>dubbo-spring-boot-starterartifactId>
<version>2.7.8version>
dependency>
dependencies>
dependencyManagement>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-compiler-pluginartifactId>
<version>3.8.1version>
<configuration>
<source>1.8source>
<target>1.8target>
configuration>
plugin>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
<version>2.3.4.RELEASEversion>
plugin>
plugins>
pluginManagement>
build>
project>
6. 启动Zookeeper
确保Zookeeper在本地运行，默认端口为 2181。可以通过下载Zookeeper并运行以下命令启动Zookeeper：
bin/zkServer.sh start
7. 启动服务提供者和消费者
- 启动用户服务：运行
UserServiceApplication类。 - 启动好友服务：运行
FriendServiceApplication类。 - 启动消息服务：运行
MessageServiceApplication类。 - 启动前端应用：运行
FrontendApplication类。
8. 测试服务
访问前端应用的用户获取、好友添加和消息发送接口：