The idea is to construct a queue of tasks, in terms of Threads, to get executed one after the other. The JDK itself has classes to do Thread Pools: java.util.concurrent.ExecutorService.

This is just one way of using it.

Try the following code,

Thread Pool Class

  package gunith.evillab;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;

  public class SingleThreadPool {
    public static void main(String[] args) {
      ExecutorService xServ = Executors.newSingleThreadExecutor();
      for(int i=0;i<4;i++){
        xServ.submit(new Boogie(i));
      }
      xServ.shutdown();
      System.out.println("Sent all the Boogie's to dance");
    }
  }

The (Dummy) Runnable Class

class Boogie implements Runnable{
  int id;
  public Boogie(int id) {
    this.id = id;
  }
  @Override
  public void run() {
    for (int i=0;i<3;i++) {
      System.out.println(id + " does the boogie times x " + i);
      try {
        Thread.sleep(3*1000);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
}