在 Spring 引导 Maven 项目中创建精简 jar 时出现问题

Question

I have a Maven Spring Boot Micro Services Java project arranged into a parent module and 6 sub-modules. In the parent pom.xml, I have included the Maven Spring Boot Plugin in the build/plugins section: -

    <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <version>2.1.5.RELEASE</version>
    </plugin>

5 of my 6 sub-modules are Micro Services, and the above plugin ensures that these are built into executable Spring Boot jars, including all dependencies, when I run mvn clean install

However, the other sub-module is just a standard Java utility project and does not have a Spring Boot context. When I try to build, I see the following error: -

 Execution repackage of goal org.springframework.boot:spring-boot-maven-plugin:2.1.5.RELEASE:repackage failed: Unable to find main class -> [Help 1]

This is expected as this sub-module is not a Spring Boot application and does not have a main class. I tried to fix this by overriding the Spring Boot Maven plugin in the pom file of that sub-module so that it is treated as a standard 'thin' jar: -

        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <dependencies>
                <!-- The following enables the "thin jar" deployment option. -->
                <!-- This creates a normal jar, not an executable springboot jar -->
                <dependency>
                    <groupId>org.springframework.boot.experimental</groupId>
                    <artifactId>spring-boot-thin-layout</artifactId>
                    <version>1.0.11.RELEASE</version>
                </dependency>
            </dependencies>
        </plugin>

However, I am still seeing exactly the same error in my Maven build. I would be most grateful for any hints or pointers on this one.

Answer 1

You can skip the execution of the repackage plugin for your utility module by overriding the configuration in that module.

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <skip>true</skip>
    </configuration>
</plugin>