Making the time lapsed from Thread.sleep method random

try:

int rand=new java.util.Random(System.currentTimeMillis()).nextInt(3)+3;
t.sleep( rand ) ;

ehm, i forgot those are milliseconds, so change it in:

int rand=new java.util.Random(System.currentTimeMillis()).nextInt(3000)+3000;
t.sleep( rand ) ;

how do i use

>int rand=new

i've put it under the main class but it causes errors

Random random=new java.util.Random(System.currentTimeMillis());
int time=random.nextInt(2000)+3000;
Thread.sleep(time);

to see how it works:

       Random r=new java.util.Random(System.currentTimeMillis());
       for (int i=0; i< 100; i++){
          int time=r.nextInt(2000)+3000;
          System.out.println(time);
       }

or better, always to see how it works:

       Random r=new java.util.Random(System.currentTimeMillis());
       for (int i=0; i< 100; i++){
          int time=r.nextInt(2000)+3000;
          System.out.println(time);
          try {
            Thread.sleep(time);
          } catch (InterruptedException e) {
            e.printStackTrace();
          }
       }

sorry, could you please show me how to put that in here

 while (index < array_of_clips.length) {
                    array_of_clips[index].play();
                    try {
                        Thread.sleep(3000); // is one second enough??
                    } catch (InterruptedException ex) {
                        return; // I should be interrupted if the user want to stop the clips
                    }

                    array_of_clips[index].stop();

instead of the    Thread.sleep(3000);