Adding Spring boot application as a dependency to another spring boot application

 The Spring Boot Maven and Gradle plugins both package our application as executable JARs – such a file can't be used in another project since class files are put into BOOT-INF/classes. This is not a bug, but a feature.

In order to share classes with another project, the best approach to take is to create a separate jar containing shared classes, then make it a dependency of all modules that rely on them.

But if that isn't possible, we can configure the plugin to generate a separate jar that can be used as a dependency.

Suppose we have two projects

1- general_definitions_app

2- cutstomer_service_app

we want to add "general_definitions_app" as a dependency to "cutstomer_service_app"

 Steps:

1- open  general_definitions_app , then open the pom.xml file

2- serach for the plugin "spring-boot-maven-plugin" and modify it to be 

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

we added <configuration>
                    <classifier>exec</classifier>
                </configuration>

to generate separate jar file with suffix "-exec"

3- click save

4- using CMD , go to the location of the  "general_definitions_app"

issue this command:

mvn clean

mvn install

this will install two separate jars in the local repos ".m2" folder in you machine, the first one is for the spring boot app , the second one will be used as dependencies in other projects

5- open the "cutstomer_service_app" , then open the pom.xml file

6- add dependencies. Example:

<dependency>
            <groupId>org.dhaman.opr</groupId>
            <artifactId>opr-gen-definitions</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

7- update the depencencies