Click here to Skip to main content
14,769,975 members
Please Sign up or sign in to vote.
0.00/5 (No votes)
See more:
Hi,

I am a beginner in Multi-Threading.

While doing a simple multi-threading program I get an error as follows:

.\Thread.java:24: cannot find symbolsymbol : method sleep(int)
location: class Thread
Thread.sleep(500);

^


I get the same error with Thread.start() function as well.
Can anybody help me to find a solution for the same?
Below is my program code:

  class NewThread implements Runnable {
   Thread t;
   NewThread() {
      // Create a new, second thread
      t = new Thread(this, "Demo Thread");
      System.out.println("Child thread: " + t);
      t.start(); // Start the thread
   }
      // This is the entry point for the second thread.
   public void run() {
      try {
         for(int i = 5; i > 0; i--) {
            System.out.println("Child Thread: " + i);
            // Let the thread sleep for a while.
            Thread.sleep(500);
         }
     } catch (InterruptedException e) {
         System.out.println("Child interrupted.");
     }
     System.out.println("Exiting child thread.");
   }
}
class ThreadDemo1 {
   public static void main(String args[]) {
      new NewThread(); // create a new thread
      try {
         for(int i = 5; i > 0; i--) {
           System.out.println("Main Thread: " + i);
           Thread.sleep(1000);
         }
      } catch (InterruptedException e) {
         System.out.println("Main thread interrupted.");
      }
      System.out.println("Main thread exiting.");
   }
}
Posted
Updated 13-Oct-10 22:38pm
v2
Comments
Richard MacCutchan 14-Oct-10 8:06am
   
Your comment below is correct; although you would have trouble starting any Java program if it was not set.

Are you sure that your classpath is set correctly? I have copied your code into my IDE (eclipse) and it runs fine in there and also from the command line.
   
Comments
vidhyaej 14-Oct-10 7:44am
   
you mean the path which we set in the EnvironmentVariables ,isn't it?
C:\Program Files\Java\jdk1.6.0_21\bin .Am i correct?
Oh..my goodness....i had been trying out many programs and faced the same problem with all of them....

Now i got the reason.It may help some of you(<b>beginners like me</b>)

i had saved a file <b>'Thread.java' </b>unknowingly in the same folder and that created all these problems...i renamed it and all errors were rectified....

Thanks to Richard because he made me think of such a possibility (by asking whether the classpath is correct...actually the class refered to, in the error report was Thread.java which is actually a built in class in java.lang package )
   

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)




CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900