Here you can find the source of createDemoFrame(String title)
public static JFrame createDemoFrame(String title)
//package com.java2s; /*/*from w w w .ja v a 2 s . c o m*/ * OpenSwingUtil.java 7/23/13 12:43 PM * * Copyright (C) 2012-2013 Nick Ma * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 3 * of the License, or any later version. * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ import java.awt.*; import javax.swing.*; public class Main { public static JFrame createDemoFrame(String title) { JFrame frame = new JFrame(title); frame.setSize(400, 320); Dimension d = Toolkit.getDefaultToolkit().getScreenSize(); frame.setLocation((d.width - frame.getSize().width) / 2, (d.height - frame.getSize().height) / 2); return frame; } }