Here you can find the source of messageWarning(String s)
public static void messageWarning(String s)
//package com.java2s; /******************************************************************************* * Copyright (c) 2001, 2007 Mathew A. Nelson and Robocode contributors * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://robocode.sourceforge.net/license/cpl-v10.html * * Contributors://from www.j av a2 s. c o m * Mathew A. Nelson * - Initial API and implementation * Flemming N. Larsen * - Moved window related methods from robocode.util.Utils into this class *******************************************************************************/ import javax.swing.JOptionPane; public class Main { public static void messageWarning(String s) { JOptionPane.showMessageDialog(null, s, "Warning", JOptionPane.WARNING_MESSAGE); } }