How to add JAR file to an existing WAR file web-inf/lib folder?

Question

My setup is the following:

• I have a war file that is not under my control (I can only pull it as dependency) which is a Spring Boot web application
• I have a jar file that I would like to add to web-inf/lib folder so that the war file sees it on its classpath

So far I was deploying the war file to my local Tomcat and added the jar to the lib folder of the Tomcat installation. I would like to switch to a single executable war file so that I can run it via command line and not using separate Tomcat instance.

How can I achieve my goal using Maven?

Answer 1

You can give theoverlays feature of the maven-war-plugin a try but I'm unsure, if web-inf/lib is used by spring boot standalone executables

Answer 2

Robert's suggestion was correct, I would like to summarize what exactly I had to do:

1. Use maven-war-plugin with an overlay pointing to the war dependency

2. Set up the plugin correctly:

   <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-war-plugin</artifactId> <version>3.3.0</version> <configuration> <recompressZippedFiles>false</recompressZippedFiles> <archive> <manifestFile>src/main/resources/MANIFEST.MF</manifestFile> <compress>false</compress> </archive> <failOnMissingWebXml>false</failOnMissingWebXml>... </build>

I had to explicitly copy the manifest file (it was ignored) and disable jar compression.