【多个SpringBoot模块项目如何变成聚合项目】

【前言】

项目虽然是Eureka、OpenFeign 进行服务注册和服务调用，但是每个模块都是一个单独的SpringBoot，启动每个模块都需要单独启动一个idea,觉得这个过于繁琐，现在想把项目变成一个聚合项目，只需要启动一个idea即可。

【过程】

1、新建maven聚合父工程

快速创建一个maven工程，删除无关文件，只保留pom.xml

pom文件如下：

<?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">

    <!-- 基本信息 -->
    <description>SpringBoot 多模块构建示例</description>
    <modelVersion>4.0.0</modelVersion>
    <name>project-aggregation</name>
    <packaging>pom</packaging>

    <!-- 项目说明：这里作为聚合工程的父工程 -->
    <groupId>com.pu</groupId>
    <artifactId>project-aggregation</artifactId>
    <version>1.0-SNAPSHOT</version>

    <!-- 继承说明：这里继承SpringBoot提供的父工程 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/>
    </parent>

    <!-- 模块说明：这里声明多个子模块 -->
    <modules>
        <module>helloworld</module>
        <module>mybatistest</module>
    </modules>

    <!-- 在properties中统一控制依赖包的版本，更清晰-->
    <properties>
        <java.version>1.8</java.version>
        <fastjson.version>1.2.32</fastjson.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
        <feign.version>2.1.1.RELEASE</feign.version>
        <eureka-client.version>2.1.1.RELEASE</eureka-client.version>
        <zkclient.version>0.10</zkclient.version>
        <poi.version>3.13</poi.version>
        <lombok.version>1.18.6</lombok.version>
    </properties>

    <!--在此处统一加，子项目pom就可以不用引入了-->
    <dependencies>
        <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>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
        </dependency>
    </dependencies>
    <!--dependencyManagement用于管理依赖版本号-->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
                <version>${eureka-client.version}</version>
            </dependency>
            <!--feign -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>${feign.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>${fastjson.version}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi</artifactId>
                <version>${poi.version}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi-ooxml-schemas</artifactId>
                <version>${poi.version}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi-ooxml</artifactId>
                <version>${poi.version}</version>
            </dependency>
            <!-- lombok -->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
        </dependencies>

    </dependencyManagement>

    <!--该插件作用是打一个可运行的包，必须要写在需要打包的项目里。这里的父模块不需要打包运行，所以删掉该插件。-->
    <!--<build>-->
    <!--<plugins>-->
    <!--<plugin>-->
    <!--<groupId>org.springframework.boot</groupId>-->
    <!--<artifactId>spring-boot-maven-plugin</artifactId>-->
    <!--</plugin>-->
    <!--</plugins>-->
    <!--</build>-->

</project>

2.建子模块module项目helloworld

父工程右键–》new–>module

<?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>

    <!-- 基本信息 -->
    <groupId>com.pu</groupId>
    <artifactId>helloworld</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>helloworld</name>
    <description>Demo project for Spring Boot</description>

    <!-- 继承本项目的父工程 -->
    <parent>
        <groupId>com.pu</groupId>
        <artifactId>project-aggregation</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath><!-- lookup parent from repository -->
    </parent>

    <dependencies>
       
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

【细节】

（1）在进行子模块创建的时候，下面的relativePath需要执行父POM的地址才能依赖上

    <parent>
        <groupId>com.example</groupId>
        <artifactId>intellnm</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath></relativePath>
    </parent>

正确的应该是

    <parent>
        <groupId>com.example</groupId>
        <artifactId>intellnm</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>

这样就可以避免出现下面这个问题了。
Could not find artifact com.example:intellnm:pom:0.0.1-SWAPSHOT and ‘parent.relativePath’ points at no local POM line 11, column 10 -> [Help 2]