Start by using multiple jar files that are referenced from a single manifest, and see if that works for you.
That's not rocket science, but not for the faint of heart (or beginners) either.
Note : The Class-Path header points to classes or JAR files on the local network, not JAR files within the JAR file or classes accessible over internet protocols. To load classes in JAR files within a JAR file into the class path, you must write custom code to load those classes. For example, if MyJar.jar contains another JAR file called MyUtils.jar, you cannot use the Class-Path header in MyJar.jar's manifest to load classes in MyUtils.jar into the class path.
What does "get in 2nd url" mean