Java tutorial
//package com.java2s; import java.awt.Container; import java.awt.Dimension; import java.awt.Point; import java.awt.Toolkit; public class Main { public static void setScreenCenter(Container container) { Toolkit toolkit = Toolkit.getDefaultToolkit(); Dimension screenDimension = toolkit.getScreenSize(); int width = container.getWidth(); int height = container.getHeight(); Point point = new Point(); point.setLocation((screenDimension.getWidth() - width) / 2, (screenDimension.getHeight() - height) / 2); container.setLocation(point); } }