Java tutorial
/* * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002. * All rights reserved. Software written by Ian F. Darwin and others. * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */ import java.awt.GridLayout; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; import javax.swing.ButtonGroup; import javax.swing.JCheckBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JRadioButton; import javax.swing.JTextField; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; /** * Standalone Swing GUI application for demonstrating REs. <br/>TODO: Show the * entire match, and $1 and up as captures that matched. * * @author Ian Darwin, http://www.darwinsys.com/ * @version #Id$ */ public class REDemo extends JPanel { protected Pattern pattern; protected Matcher matcher; protected JTextField patternTF, stringTF; protected JCheckBox compiledOK; protected JRadioButton match, find, findAll; protected JTextField matchesTF; /** "main program" method - construct and show */ public static void main(String[] av) { JFrame f = new JFrame("REDemo"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); REDemo comp = new REDemo(); f.setContentPane(comp); f.pack(); f.setLocation(200, 200); f.setVisible(true); } /** Construct the REDemo object including its GUI */ public REDemo() { super(); JPanel top = new JPanel(); top.add(new JLabel("Pattern:", JLabel.RIGHT)); patternTF = new JTextField(20); patternTF.getDocument().addDocumentListener(new PatternListener()); top.add(patternTF); top.add(new JLabel("Syntax OK?")); compiledOK = new JCheckBox(); top.add(compiledOK); ChangeListener cl = new ChangeListener() { public void stateChanged(ChangeEvent ce) { tryMatch(); } }; JPanel switchPane = new JPanel(); ButtonGroup bg = new ButtonGroup(); match = new JRadioButton("Match"); match.setSelected(true); match.addChangeListener(cl); bg.add(match); switchPane.add(match); find = new JRadioButton("Find"); find.addChangeListener(cl); bg.add(find); switchPane.add(find); findAll = new JRadioButton("Find All"); findAll.addChangeListener(cl); bg.add(findAll); switchPane.add(findAll); JPanel strPane = new JPanel(); strPane.add(new JLabel("String:", JLabel.RIGHT)); stringTF = new JTextField(20); stringTF.getDocument().addDocumentListener(new StringListener()); strPane.add(stringTF); strPane.add(new JLabel("Matches:")); matchesTF = new JTextField(3); strPane.add(matchesTF); setLayout(new GridLayout(0, 1, 5, 5)); add(top); add(strPane); add(switchPane); } protected void setMatches(boolean b) { if (b) matchesTF.setText("Yes"); else matchesTF.setText("No"); } protected void setMatches(int n) { matchesTF.setText(Integer.toString(n)); } protected void tryCompile() { pattern = null; try { pattern = Pattern.compile(patternTF.getText()); matcher = pattern.matcher(""); compiledOK.setSelected(true); } catch (PatternSyntaxException ex) { compiledOK.setSelected(false); } } protected boolean tryMatch() { if (pattern == null) return false; matcher.reset(stringTF.getText()); if (match.isSelected() && matcher.matches()) { setMatches(true); return true; } if (find.isSelected() && matcher.find()) { setMatches(true); return true; } if (findAll.isSelected()) { int i = 0; while (matcher.find()) { ++i; } if (i > 0) { setMatches(i); return true; } } setMatches(false); return false; } /** Any change to the pattern tries to compile the result. */ class PatternListener implements DocumentListener { public void changedUpdate(DocumentEvent ev) { tryCompile(); } public void insertUpdate(DocumentEvent ev) { tryCompile(); } public void removeUpdate(DocumentEvent ev) { tryCompile(); } } /** Any change to the input string tries to match the result */ class StringListener implements DocumentListener { public void changedUpdate(DocumentEvent ev) { tryMatch(); } public void insertUpdate(DocumentEvent ev) { tryMatch(); } public void removeUpdate(DocumentEvent ev) { tryMatch(); } } }