Step 1 Create project folder structure
Create a folder as the root-folder of the project, mkdir ex_multimodule.
Inside the root-folder, make the folders for library & application.
cd ex_multimodule
mkdir library application
The folder structure as below.
E:\Downloads\documents\STS_projects\ex_multimodules>dir
驱动器 E 中的卷是 Tools
卷的序列号是 E885-5830
E:\Downloads\documents\STS_projects\ex_multimodules 的目录
2018/07/11 13:57 <DIR> .
2018/07/11 13:57 <DIR> ..
2018/07/11 13:57 <DIR> application
2018/07/11 13:57 <DIR> library
0 个文件 0 字节
4 个目录 56,900,472,832 可用字节
Step 2 Create Maven configuration for Multi-Module project
In the root-folder of the project, execute mvn io.takari:maven:wrapper to let Maven to build the project structure.
Check the folder structure after execution.
E:\Downloads\documents\STS_projects\ex_multimodules>tree /f .
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\EX_MULTIMODULES
│ mvnw
│ mvnw.cmd
│
├─.mvn
│ └─wrapper
│ maven-wrapper.jar
│ maven-wrapper.properties
│ MavenWrapperDownloader.java
│
├─application
└─library
Step 3 Prepare the pom.xml for the whole 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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.springframework</groupId>
<artifactId>gs-multi-module</artifactId>
<version>0.1.0</version>
<packaging>pom</packaging>
<modules>
<module>library</module>
<module>application</module>
</modules>
</project>
After that, we can check the content of the pom.xml file.
E:\Downloads\documents\STS_projects\ex_multimodules>type 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>org.springframework</groupId>
<artifactId>gs-multi-module</artifactId>
<version>0.1.0</version>
<packaging>pom</packaging>
<modules>
<module>library</module>
<module>application</module>
</modules>
</project>
Step 4 Make the folders for the library project
E:\Downloads\documents\STS_projects\ex_multimodules>cd library
E:\Downloads\documents\STS_projects\ex_multimodules\library>mkdir src\main\java\hello\service
E:\Downloads\documents\STS_projects\ex_multimodules\library>tree .
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\EX_MULTIMODULES\LIBRARY
└─src
└─main
└─java
└─hello
└─service
Step 5 Prepare Maven for library project
The Spring Boot plugin is NOT used in the library project at all. The main function of the plugin is to create an executable "über-jar" which we don’t need (and don’t want) for a library.
Below is the content of library\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>gs-multi-module-library</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Although the Spring Boot Maven plugin is not being used, you do want to take advantage of Spring Boot dependency management, so that is configured using the spring-boot-starter-parent from Spring Boot as a parent project.
Step 6 Create an Application project
Do not use the same package as the library (or a parent of the library package) unless you want to include all Spring components in the library by @ComponentScan by default in the application.
E:\Downloads\documents\STS_projects\ex_multimodules>cd application
E:\Downloads\documents\STS_projects\ex_multimodules\application>mkdir src\main\java\hello\app
E:\Downloads\documents\STS_projects\ex_multimodules\application>tree .
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\EX_MULTIMODULES\APPLICATION
└─src
└─main
└─java
└─hello
└─app
Step 7 Create Maven configuration for Application project
Below is the content of 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>
<groupId>com.example</groupId>
<artifactId>gs-multi-module-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.example</groupId>
<artifactId>gs-multi-module-library</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Step 8 Open the project in Spring-Tool-Suite
To simplify the code writing, we can use Spring-Tool-Suite to open the project.
Use [File] -- [Open Projects from File System...] --- [Directory...] to locate to the root-folder of the project, S-T-S will scan the project and the modules definition automatically.
