How to run a class from Jar which is not the Main-Class in its Manifest file

Question

I have a JAR with 4 classes, each one has Main method. I want to be able to run each one of those as per the need. I am trying to run it from command-line on Linux box.

Answer 1

You can execute any class which has a public final static main method from a JAR file, even if the jar file has a Main-Class defined.

Execute Main-Class:

java -jar MyJar.jar  // will execute the Main-Class

Execute another class with a public static void main method:

java -cp MyJar.jar com.mycomp.myproj.AnotherClassWithMainMethod

Note: the first uses -jar, the second uses -cp.