i face a problem here..

i am creating a compiler for java, the compilation part is done,and now i have a problem in the running the class compiled..

i use the runtime.getruntime().exec() method to run the class..

and what happen is, for example, i have a simple java file like

public static void main(String[]args)
{
System.out.print("This message");
}
and i run this class

it will show a line in the command prompt "this message",but after that it will closed straigth away, thus, the user has no chance to see the output of the class..

can anyone help me, sorry for my bad english
hope that you all understand
thanks