If you need to use the return value from a Java program in the shell script that called it then this example will show you how.
Java program
public class TestReturn
{
   public static boolean doStuff()
   {
       // your code here
       // return true if successful, false otherwise
   }

   public static void main(String[] args)
   {
       if(doStuff())
       {
           // success
           System.exit(0);
       }
       else
       {
           // failure
           System.exit(-1);
       }
   }
}
Shell script
#!/bin/sh
java TestReturn
result=$?
echo $result
In bash script $? means the result of the previous command. You could also use
#!/bin/sh
result = $(java TestReturn)
echo $result