My APImage for Java isn't working?

The code for my entire class is:

package picturetest;
import images.APImage;

public class PictureTest{

    public static void main(String[]args){
        APImage image = new APImage("cat4.jpg"); //Line 12
        image.draw();

    }

}

When I run this I get the following error:

javax.imageio.IIOException: Can't read input file!
Exception in thread "main" java.lang.NullPointerException
    at images.APImage.setWindowAttributes(APImage.java:230)
    at images.APImage.<init>(APImage.java:86)
    at picturetest.PictureTest.main(PictureTest.java:12)
Java Result: 1