如何在Java项目下新建一个子moudle

1. 流程

原有项目

1.1 确认当前项目为 Maven 父模块

从上传的 pom.xml 文件可以看到，这个项目本身是一个独立的 Maven 项目。为了支持子模块，你需要将这个项目改造成父模块。

检查 POM 文件：确保当前项目的 pom.xml 文件中有以下内容：

• <packaging> 设置为 pom（即父模块）。
• 子模块的 <modules> 节点。

<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.landinck</groupId>
    <artifactId>tujian-java</artifactId>
    <version>0.0.1</version>
    <packaging>pom</packaging> <!-- 修改为 pom -->

    <modules>
        <!-- 子模块会在这里列出 -->
    </modules>

    <properties>
        <!-- 保持原有内容 -->
    </properties>

    <dependencies>
        <!-- 保持原有内容 -->
    </dependencies>
</project>

1.2 创建子模块目录

在项目根目录下，创建一个新的子模块目录。例如：tujian-service。
在子模块目录中创建一个新的 pom.xml 文件。

1.3 配置子模块的 POM 文件

为子模块定义一个独立的 POM 文件，并将其设置为从父模块继承。

<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.landinck</groupId>
        <artifactId>tujian-java</artifactId>
        <version>0.0.1</version>
    </parent>

    <artifactId>tujian-service</artifactId>
    <name>Tujian Service Module</name>

    <dependencies>
        <!-- 定义该子模块需要的依赖 -->
    </dependencies>
</project>

1.4 在父模块中声明子模块

编辑父模块的 pom.xml 文件，将新建的子模块路径添加到 <modules> 节点中：

<modules>
    <module>tujian-service</module>
</modules>

1.5 构建并验证

回到父模块的根目录，运行以下命令以构建项目：

mvn clean install

1.6 子模块的代码结构

在子模块目录中，按照标准 Maven 项目结构组织代码：

tujian-service
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com/landinck/tujian/service
│   │   └── resources
│   └── test
│       └── java
└── pom.xml

2. 其他项目例子

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>cn.tedu</groupId>
    <artifactId>straw</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>straw</name>
    <description>Demo project for Spring Boot</description>

    <packaging>pom</packaging>

    <!-- 子项目 -->
    <modules>
        <module>straw-portal</module>
        <module>straw-generator</module>
        <module>straw-resource</module>
        <module>straw-aop</module>
    </modules>

    <properties>
        <java.version>1.8</java.version>
        <mybatis.plus.version>3.3.1</mybatis.plus.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <pagehelper.starter.version>1.3.0</pagehelper.starter.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper-spring-boot-starter</artifactId>
                <version>${pagehelper.starter.version}</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis.plus.version}</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-extension</artifactId>
                <version>${mybatis.plus.version}</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>${mybatis.plus.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>cn.tedu</groupId>
        <artifactId>straw</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>cn.tedu</groupId>
    <artifactId>straw-portal</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>straw-portal</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- AspectJ -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
        </dependency>

        <!-- Spring AOP -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
        </dependency>
        
        <!-- hutool -->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.16</version>
        </dependency>
        
        <!-- 分页 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
        </dependency>

        <!-- 验证框架 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

        <!-- thymeleaf -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.thymeleaf.extras</groupId>
            <artifactId>thymeleaf-extras-springsecurity5</artifactId>
        </dependency>

        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-extension</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>

        <!-- Spring Security -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <!-- Spring Security Test -->
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- swagger2 -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- SpringBoot打包工具 -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>