Using the synchronized keyword in Java.java

threadsynch;

class Printer
{
    synchronized void printThis(Thread t, String text)
    {
        System.out.println("My thread ID: " + t);

        /* let the current thread sleep */
        /* so that the thread-scheduler context-switches */
        /* to another thread, introducing a race condition */
        try
        {
            Thread.sleep(100);
        }
        catch(InterruptedException exp)
        {
            System.out.println("INTERRUPTED: Thread.sleep()");
        }

        /* now print the string */
        System.out.println("My payload: " + text);
    }
}

class ThreadCreator implements Runnable
{
     String txt;
     Printer dest;
     Thread thr;

     /* Initialize and create the threads */
     public ThreadCreator(Printer d, String t)
     {
         dest = d;
         txt = t;

         thr = new Thread(this);
         thr.start();
     }

     public void run()
     {
         dest.printThis(thr, txt);
     }
}

public class Main
{
    public static void main(String[] args)
    {
        /* Creator */
        Printer destination = new Printer();

        /* Create 4 sample threads */
        ThreadCreator tc1 = new ThreadCreator(destination, "the quick");
        ThreadCreator tc2 = new ThreadCreator(destination, "brown fox");
        ThreadCreator tc3 = new ThreadCreator(destination, "jumps over");
        ThreadCreator tc4 = new ThreadCreator(destination, "the lazy dog");

        /* Wait for all threads to join */
        try
        {
            tc1.thr.join();
            tc2.thr.join();
            tc3.thr.join();
            tc4.thr.join();
        }
        catch(InterruptedException exp)
        {
            System.out.println("INTERRUPTED: Thread.join()");
        }
    }
}