Maven: Including a META-INF folder in the classes folder

Question

I have a very simple WAR project and I want to include a directory named META-INF at the top of the classes output folder where all the compiled Java classes ar

Answer 1

In general, for a Java-based Maven project, non-source files should go in the src/main/resources sub-directory of the project. The contents of that resources directory are copied to the output directory (by default, target/classes) during the process-resources phase of the build.

For Maven WAR projects, it is slightly more complicated: there is also the src/main/webapp directory, wherein Maven expects to find WEB-INF/web.xml. To build your WAR file, that file must exist; otherwise, you'll see an error message like this:

[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)

As the WEB-INF directory must exist under src/main/webapp, I'd recommend avoiding defining it again in src/main/resources. Although this is perfectly valid and the contents of the two directories will be merged, it can get confusing if a file is defined in both. The contents of src/main/resources will take precedence as they are copied over the top of the contents from src/main/webapp.