Fixing Error: Unreported Exception InterruptedException

Question

I'm new to Java. I was just searching how to make a Java program wait, and it said to use the Thread.sleep() method. However, when I do this it comes up with an error:

error: unreported exception InterruptedException; must be caught or declared to be thrown

I fixed that by adding throws InterruptedException to the method declaration, and now it works.

However, when calling the method, I got the error again. People say to use a throw and catch block, but I'm not sure how to do that yet. Could somebody help me here?

Anyways, code for Draw.java (with sleep() method):

package graphics.utilities;

public class Draw {
  public static void DS(int[] c)
    throws InterruptedException {
    \\ .. Drawing Algorithms
    Thread.sleep(2000);
    \\ .. More Drawing Algorithms
  }
}

And in Square.java (calling DS()):

package graphics.shapes;

import graphics.utilities.*;

public class Square implements Graphics {
  int x1,y1,s;
  public Square(int x1,int y1,int s) {
    this.x1 = x1;
    this.y1 = y1;
    this.s = s;
  }
  public void GC() {
    System.out.printf("Square Coordinates:%n Start Point:%n  x: %d%n  y: %d%n Height/Width: %d%n%n" , this.x1,this.y1,this.s);
  }
  public void D() {
    int x2 = x1 + s;
    int y2 = y1;
    int x3 = x1 + s;
    int y3 = y1 + s;
    int x4 = x1;
    int y4 = y1 + s;

    int[] c = {x1,y1,x2,y2,x3,y3,x4,y4};
    Draw.DS(c);
  }
}

Thanks.

Answer 1

Provided example demonstrates how to do exception pass up the call chain (up the method call chain). For this your method declaration contains a throws InterruptedException.

Alternative approach is to handle exception in the method it occurred: in your case add

try 
{
    Thread.sleep(2000);
} 
catch(InterruptedException e)
{
     // this part is executed when an exception (in this example InterruptedException) occurs
}

After you added try {} catch() {} block, remove "throws InterruptedException" from the method DS.

You can wrap other lines with try {} catch() {} block as required. Read about Java exceptions.