Your code doesn't make any sense and is incomplete.

Obviously this makes it really hard to help you in any way but guess.

Nothing to do with "Other Languages", so I moved it here.
There is an article in the Learning section of the site, about using Eclipse to code sketches.
You use NetBeans, but the general information about making a sketch in pure Java should be reusable.

Change my question.
and try in this way

1. MyGrumpy setup = new MyGrumpy();
2. setup.setup();
3. img = setup.loadImage("Grumpy.jpg");
4. setup.image(img,20,20,640,360);

have an error too..

1. Exception in thread "main" java.lang.NullPointerException
2.     at processing.core.PApplet.size(PApplet.java:1646)
3.     at processing.core.PApplet.size(PApplet.java:1619)
4.     at grumpy.MyGrumpy.setup(MyGrumpy.java:29)
5.     at grumpy.Interface.<init>(Interface.java:22)
6.     at grumpy.Grumpy.main(Grumpy.java:14)

Your code still doesn't make any sense and is still incomplete.

What is a MyGrumpy? If you want to use Processing in another IDE you should extend PApplet.

As PhiLho suggested, check out the resources on using Processing in Eclipse.

Then you will find good practices on how to do this.

Processing sketches in the IDE are actually close of what you do in the PDE: you have a setup() and a draw() method inside a class extending PApplet. And you still do the loadImage() inside the setup().

Why do you use a JFrame? Is that a requirement of your project? Try searching the forum, some other people are talking about integrating a Processing sketch in a Swing application.