From the source:
To extract only certain files from a jar file, supply their filenames:
C:\Java> jar xf myFile.jar foo bar
Using wildcards is a shell thing, and you should not expect it to work when extracting from a JAR file (which, as you’ve realized, is the case).
What you can do, is supply a list of the files you want to extract, via the @ modifier:
jar xf my.jar @myfiles.lst
where myfiles.lst would be:
com/my/MyClass.java
com/my/MySecondClass.java
This file could easily be created automatically with creative use of jar tvf, awk and your desired extraction pattern. I’ll leave that as an exercise and/or another SO question 🙂
Or you could use unzip – a JAR file is basically a zip-file.
Cheers,