How do you recompile a jar file?

Question

I took an old jar file and edited it. Now i have a folder that has all the files and I want to recompile them back to a jar file. How do i do this?

Answer 1

Jar files aren't "compiled" in the normal sense of the word. But you just create one with the jar command:

jar cvf myfile.jar file1 file2 etc

You can use globbing as normal:

jar cvf ../myfile.jar *

Run jar -? or read the docs for more information.

Note that for an executable jar file, you'll need to specify the manifest file as well.

Answer 2

How did you edit it?

Anyway, jar files follow the same format as regular zip files. If you want to update the content of the jar ( probably with a new file ) you could do:

jar -uf yourJar.jar  path/to/updated/Class.class 

That would update your jar with the file path/to/updated/Class.class If there's already a class with that name in that path, it would be replaced. If is not it would be created.

After this your jar is up to date.