Guaranteeing that single instance runs at the same time

public class BgwBufferRetry {

        public static void main(String[] args) throws Exception {

                if (isAnotherInstanceRunning())

                        return;

        }

       

        private static boolean isAnotherInstanceRunning(){

                try{

                    RandomAccessFile randomFile = new RandomAccessFile("ClassName.class","rw");

                    FileChannel channel = randomFile.getChannel();

                    if(channel.tryLock() == null) {

                        System.out.println("Already Running...");

                        return true;

                    }

                }catch( Exception e ) {

                        System.out.println(e.toString());

                    return true;

                }

                return false;

        }

}