JPanel or Canvas?

Newbie & Debugging Questions
#1

I have not been programming for too long to know or understand how different java classes is doing when it comes to performance…

This might be a normal question, I did search the forum but didnt find an answear to it.
Which is best to use: JFrame or Canvas?
What are the Pros and Cons with each?

And also something that came to mind right now while typing:
Updating graphics on for example JPanel… Then you call the paintComponent method… But that method takes a Graphics g in its parameters… What is the correct way of calling it from for example a game loop? Should i just create an empty Graphics object on the game initialization and use that or should i actualy declare the object to something?

#2

JPanel uses Swing. Ancient, but newer.

Canvas is AWT which is long dead.

Pick JPanel - it’s lighweight. Canvas is heavy height.

Take a look at JavaFX otherwise.

#3

How about update methods when it comes to swing components like JFrame and JPanel?
When i run my application just to test the library im making it seems like they are updating themselves autoamtically…
Are they?

#4

If you are looking for performance you should be looking at OpenGL based rendering.

If you decide to stick with Java2D (IMHO a poor choice), then usually Canvas and buffer strategy is how you might write a game loop.