spring boot multi modules package - spring

Question

I am trying to use Maven to package Spring Boot with multi modules,Here my main module pom.xml :
<modules>
<module>my-data-services</module>
<module>my-message-services</module>
<module>my-common</module>
</modules>
<groupId>com.my</groupId>
<artifactId>my-multi-services</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>....</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
my-common pom.xml:
<parent>
<artifactId>my-multi-services</artifactId>
<groupId>com.my</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>my-common</artifactId>
<packaging>jar</packaging>
<dependencies>....</dependencies>
and my-data-services pom.xml:
<parent>
<artifactId>my-multi-services</artifactId>
<groupId>com.my</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>my-data-services</artifactId>
<dependencies>
<dependency>
<groupId>com.my</groupId>
<artifactId>my-common</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
my-common module is just a common utils lib not a runnable module,but when i trying to mvn clean package,exception throws below:
Execution default of goal org.springframework.boot:spring-boot-maven-p
lugin:1.4.2.RELEASE:repackage failed: Unable to find main class
then i add a main class,this module can package,but its not a lib jar, its like a runnable spring boot jar
-BOOT-INF
|
-META-INF
|
-org
and the exception throws
Failed to execute goal org.apache.maven.plugins:maven-compiler- plugin:3.1:compile (default-compile) on project my-data-services: Compilation failure: Compilation failure: package com.my.common.utils does not exist;
com.my.common.utils is in module my-common
How do i fix this problem, and in spring boot multi modules project,how to package a common utils lib without BOOT-INF

Answer 1

This happens because your modules will have the 'spring-boot-maven-plugin' added to them because it's defined in their parent.
What you need to do is move everything into submodules, even your application starter class. How I do this usually:
my-parent-module
my-service-module
my-common-module
my-web-module (or my-runtime-module in a non-web app)
The my-parent-module will have 'spring-boot-starter-parent' as it's parent but it not going to have an src folder because everything is moved into submodules.
The my-web-module will depend on the other modules and will have the 'spring-boot-maven-plugin'. You will be able to run the app with 'mvn spring-boot:run' in the my-web-module folder.