Java screen resolution (screen size) - how to get the resolution using Java

A common Java/Swing question is, "How do I determine the screen resolution (or screen size)?"

Answer: You can determine the screen resolution (screen size) using the Toolkit class. This method call returns the screen resolution in pixels, and stores the results in a Dimension object, as shown here:

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

You can then get the screen width and height as int's by directly accessing the width and height fields of the Dimension class, like this:

screenHeight = screenSize.height;
screenWidth = screenSize.width;

I thought I better mention that, because it's a little unusual to access fields directly like this (there are typically "get" methods for accessing variables). Interestingly, Dimension class does have methods named getWidth and getHeight, and they return the type double.

Setting the size of a JFrame

While I'm in the neighborhood of screen dimensions, I thought I'd mention that once you have the screen dimensions, you can easily set the JFrame size to half the height and half the width of the screen, like this:

frame.setSize(screenWidth / 2, screenHeight / 2);

Nothing sensational here, but I thought I'd mention this, as it is something I do for most Swing applications (at least those where I don't bother to remember the last user-specific height and width settings).