Spring Boot 多模块开发完整指南

Spring Boot 多模块开发完整指南

Spring Boot 多模块开发是将一个大型项目拆分成多个相互关联的模块，每个模块有特定的职责。这种架构提高了代码的可维护性、可复用性和团队协作效率。

1. 多模块项目结构

1.1 典型的项目结构

my-project/
├── pom.xml (父POM)
├── common/ (通用模块)
│   ├── src/
│   └── pom.xml
├── domain/ (领域模型模块)
│   ├── src/
│   └── pom.xml
├── service/ (业务逻辑模块)
│   ├── src/
│   └── pom.xml
├── web/ (Web接口模块)
│   ├── src/
│   └── pom.xml
└── application/ (主应用模块)
    ├── src/
    └── pom.xml

2. 创建多模块项目

2.1 创建父项目

父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>com.example</groupId>
    <artifactId>my-multi-module-project</artifactId>
    <version>1.0.0</version>
    <packaging>pom</packaging> <!-- 关键：父模块打包方式为pom -->
    
    <name>My Multi Module Project</name>
    <description>Spring Boot多模块项目示例</description>
    
    <!-- 模块声明 -->
    <modules>
        <module>common</module>
        <module>domain</module>
        <module>service</module>
        <module>web</module>
        <module>application</module>
    </modules>
    
    <!-- 父POM使用Spring Boot -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.0</version>
        <relativePath/>
    </parent>
    
    <properties>
        <java.version>11</java.version>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    
    <!-- 依赖管理 -->
    <dependencyManagement>
        <dependencies>
            <!-- 内部模块版本管理 -->
            <dependency>
                <groupId>com.example</groupId>
                <artifactId>common</artifactId>
                <version>${project.version}</version>
            </dependency>
            <dependency>
                <groupId>com.example</groupId>
                <artifactId>domain</artifactId>
                <version>${project.version}</version>
            </dependency>
            <dependency>
                <groupId>com.example</groupId>
                <artifactId>service</artifactId>
                <version>${project.version}</version>
            </dependency>
            <dependency>
                <groupId>com.example</groupId>
                <artifactId>web</artifactId>
                <version>${project.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <!-- 公共依赖 -->
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

2.2 创建common模块

common/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>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>my-multi-module-project</artifactId>
        <version>1.0.0</version>
    </parent>
    
    <artifactId>common</artifactId>
    <packaging>jar</packaging>
    
    <dependencies>
        <!-- 通用工具类依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
    </dependencies>
</project>

common模块代码示例：

// common/src/main/java/com/example/common/Result.java
package com.example.common;

import com.fasterxml.jackson.annotation.JsonInclude;
import lombok.Data;

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
public class Result<T> {
    private Integer code;
    private String message;
    private T data;
    
    public static <T> Result<T> success(T data) {
        Result<T> result = new Result<>();
        result.setCode(200);
        result.setMessage("success");
        result.setData(data);
        return result;
    }
    
    public static <T> Result<T> error(String message) {
        Result<T> result = new Result<>();
        result.setCode(500);
        result.setMessage(message);
        return result;
    }
}

// common/src/main/java/com/example/common/constants/ErrorCode.java
package com.example.common.constants;

public class ErrorCode {
    public static final int SUCCESS = 200;
    public static final int BAD_REQUEST = 400;
    public static final int UNAUTHORIZED = 401;
    public static final int NOT_FOUND = 404;
    public static final int INTERNAL_ERROR = 500;
}

2.3 创建domain模块

domain/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://aven.apache.org/POM/4.0.0 
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>my-multi-module-project</artifactId>
        <version>1.0.0</version>
    </parent>
    
    <artifactId>domain</artifactId>
    <packaging>jar</packaging>
    
    <dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>common</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
    </dependencies>
</project>

domain模块代码示例：

// domain/src/main/java/com/example/domain/user/entity/User.java
package com.example.domain.user.entity;

import lombok.Data;
import javax.persistence.*;

@Data
@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @Column(nullable = false, unique = true)
    private String username;
    
    @Column(nullable = false)
    private String password;
    
    private String email;
    private String phone;
}

// domain/src/main/java/com/example/domain/user/repository/UserRepository.java
package com.example.domain.user.repository;

import com.example.domain.user.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
    User findByUsername(String username);
    boolean existsByUsername(String username);
}

2.4 创建service模块

service/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>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>my-multi-module-project</artifactId>
        <version>1.0.0</version>
    </parent>
    
    <artifactId>service</artifactId>
    <packaging>jar</packaging>
    
    <dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>domain</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
    </dependencies>
</project>

service模块代码示例：

// service/src/main/java/com/example/service/user/UserService.java
package com.example.service.user;

import com.example.domain.user.entity.User;
import com.example.domain.user.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {
    
    @Autowired
    private UserRepository userRepository;
    
    public User createUser(String username, String password, String email) {
        if (userRepository.existsByUsername(username)) {
            throw new RuntimeException("用户名已存在");
        }
        
        User user = new User();
        user.setUsername(username);
        user.setPassword(password); // 实际应用中需要加密
        user.setEmail(email);
        
        return userRepository.save(user);
    }
    
    public User getUserById(Long id) {
        return userRepository.findById(id)
                .orElseThrow(() -> new RuntimeException("用户不存在"));
    }
    
    public User getUserByUsername(String username) {
        return userRepository.findByUsername(username);
    }
}

2.5 创建web模块

web/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>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>my-multi-module-project</artifactId>
        <version>1.0.0</version>
    </parent>
    
    <artifactId>web</artifactId>
    <packaging>jar</packaging>
    
    <dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>service</artifactId>
        </dependency>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>common</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>
</project>

web模块代码示例：

// web/src/main/java/com/example/web/controller/UserController.java
package com.example.web.controller;

import com.example.common.Result;
import com.example.domain.user.entity.User;
import com.example.service.user.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/users")
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @PostMapping
    public Result<User> createUser(@RequestBody User user) {
        try {
            User createdUser = userService.createUser(
                user.getUsername(), 
                user.getPassword(), 
                user.getEmail()
            );
            return Result.success(createdUser);
        } catch (Exception e) {
            return Result.error(e.getMessage());
        }
    }
    
    @GetMapping("/{id}")
    public Result<User> getUser(@PathVariable Long id) {
        try {
            User user = userService.getUserById(id);
            return Result.success(user);
        } catch (Exception e) {
            return Result.error(e.getMessage());
        }
    }
}

// web/src/main/java/com/example/web/config/WebConfig.java
package com.example.web.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {
    
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("GET", "POST", "PUT", "DELETE");
    }
}

2.6 创建application模块（主启动模块）

application/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>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>my-multi-module-project</artifactId>
        <version>1.0.0</version>
    </parent>
    
    <artifactId>application</artifactId>
    <packaging>jar</packaging>
    
    <dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <!-- 数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>
    
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

application模块代码示例：

// application/src/main/java/com/example/Application.java
package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@SpringBootApplication(scanBasePackages = "com.example")
@EntityScan("com.example.domain")
@EnableJpaRepositories("com.example.domain")
public class Application {
    
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

// application/src/main/resources/application.yml
server:
  port: 8080
  servlet:
    context-path: /api

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/myapp?useSSL=false&serverTimezone=UTC
    username: root
    password: password
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQL8Dialect

logging:
  level:
    com.example: DEBUG

3. 构建和运行

3.1 构建整个项目

在项目根目录执行：

mvn clean install

3.2 运行应用

cd application
mvn spring-boot:run

3.3 打包部署

# 打包整个项目
mvn clean package

# 只运行application模块的测试
cd application
mvn test

# 跳过测试打包
mvn clean package -DskipTests

4. 高级配置和最佳实践

4.1 配置文件分离

# application-dev.yml
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/myapp_dev

# application-prod.yml  
spring:
  datasource:
    url: jdbc:mysql://prod-db:3306/myapp_prod

4.2 自定义Starter模块

可以创建自定义starter模块供其他项目使用：

custom-starter/pom.xml：

<project>
    <!-- ... -->
    <artifactId>custom-spring-boot-starter</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>
</project>

4.3 模块间测试

// 在service模块中测试
@SpringBootTest(classes = TestConfig.class)
class UserServiceTest {
    
    @Autowired
    private UserService userService;
    
    @Test
    void testCreateUser() {
        // 测试逻辑
    }
    
    @Configuration
    @Import(UserService.class)
    static class TestConfig {
        @Bean
        public UserRepository userRepository() {
            return mock(UserRepository.class);
        }
    }
}

5. 常见问题解决

5.1 模块依赖循环

  • 使用接口分离依赖
  • 重构模块职责

5.2 组件扫描问题

  • 确保主类在根包下
  • 使用@ComponentScan指定扫描路径

5.3 配置文件优先级

1. 命令行参数
2. application-{profile}.yml
3. application.yml
4. 模块内的配置文件
posted @ 2025-12-14 16:04  binlicoder  阅读(63)  评论(0)    收藏  举报