Count and Print 1 to 10 in Real Time - Help :S

Hi all,

I need to make a Program that once the user clicks run, the Program prints out 1 to 10 with a second gap in between so it actually prints out in real time:

The output would just be:

1
2
3
4
5
6
7
8
9
10



But would print 1, then wait a second then print 2, then wait a second then print 3, etc. etc. until 10. Then the Program would just finish as normal.


How easy is would this be ? Im not asking for code but if someone could point me in the right direction as to what classes or methods i need to be using, and any advice you feel necessary, then that would be fantastic. Bearing in mind i am a beginner.


P.S. If i havn't made the requirements entirely clear then please don't hesitate to ask a question.

That should be easy. Look at the Thread class's sleep() method to handle the delay inside of a loop.

Sounds like a simple call to Thread.sleep() would do the trick.

Alternatively you could use a Timer.

It doesnt seem to like this:

Code :

---

   public static void main(String[] args) {
 
        for (int counter = 1; counter <= 10; counter++){
            System.out.println(counter);
            Thread.sleep(1000);
        }
    }
}

---

Thread.sleep(1000); is red underlined and says:

Quote:

---

Exception in thread "main" java.lang.RuntimeException:

---

Do i need to throw an exception ?

Can you post the full text of the error message that shows where the exception happened?

You don't need to throw an exception.

The code you posted should generate a compile time error, not a runtime error. Just compile it, don't try to execute it.

Here is the full error:

Quote:

---

run:
1
Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - unreported exception java.lang.InterruptedException; must be caught or declared to be thrown
at latesttasks.task15.main(task15.java:14)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

---

regards.

Quote:

---

unreported exception java.lang.InterruptedException; must be caught or declared to be thrown

---

This part says that the sleep() method can throw an exception. Your code must be ready to handle that exception. The normal way is to put that statement inside of a try{}catch(){} block to "catch" the exception.

Having added the try catch block i have the following:

Code :

---

package latesttasks;
 
// Count and Print 1 to 10 in Real Time. 
// Threads
import java.util.*;
 
public class task15 {
 
    public static void main(String[] args) {
        try {
            for (int counter = 1; counter <= 10; counter++) {
                System.out.println(counter);
                Thread.sleep(1000);
            }
         catch  (InterruptedException e){
         }
    }
}

---

But the catch line is red underlined and the program now runs and prints the 10 numbers but then the error occurs.

here is the output:

Quote:

---

run:
1
2
3
4
5
6
7
8
9
10
Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - 'catch' without 'try'
at latesttasks.task15.main(task15.java:15)
Java Result: 1
BUILD SUCCESSFUL (total time: 11 seconds)

---

Check that the {}s are properly paired.

They appear to be correctly paired

I should also add 'sleep' is yellow underlined and it says 'Thread.sleep called in loop'

--- Update ---

Update:

All fixed. Thanks for your help.