On Linux you can use the archive manager. Remember a .jar file is virtually identical to a .zip so a zipping application should be able to explore it.
Joined: Oct 07, 2009
Thank you , Ritchie, for operative answer. I use for reception of the classes structureshttp://java.decompiler.free.fr/?q=jdgui (for windows) .This program is very suitable for study of the source code jar-file, But he dos not show class relations.
Wanted in the manner of diagrams of the classes.