How to assemble multimodule maven project into one WAR?

Question

Similar question here.

I would like to get ONE resulting WAR to be deployed from 3 different maven modules. The war modules are absolutely non-conflicting :

Answer 1

This just requires a little advanced use of maven jar & war plugin.

First one that has Java classes and some WEB-INF/artifacts

Let say this represents the main WAR. You just use maven-war-plugin's Overlays feature. The most basic way is specifying the war dependency :

    
        ${groupId}
        ${rootArtifactId}-service-impl
        ${version}
        war
        runtime
    

and tell maven war plugin to merge assets of this dependency into the main war (where we are now)

    maven-war-plugin
    
        WEB-INF/web.xml,**/**.class
        
            
                
                src/main/webapp/WEB-INF
                true
                WEB-INF
            
        
    

You also include a jar type dependency on the second one (it will be a JAR in WEB-INF/lib/)

    
        ${groupId}
        ${rootArtifactId}-service
        ${version}
        jar
    

And you also need to specify dependency on the classes from the third WAR :

    
        ${groupId}
        ${rootArtifactId}-service-impl
        ${version}
        classes
        jar
    

Notice of the classifier, it is necessary because you are specifying 2 dependencies of the same artifact... To make it work, you have to set up jar plugin in the third artifact (war type artifact), regarding the classifier and the fact that you need 2 packages from one artifacts (war & jar):

    org.apache.maven.plugins
    maven-jar-plugin
    
    
        
            package
            
                jar
            
            
            
                classes
                
                    **/**.class