java Swing实现的正则表达式测试工具，,如下代码：package

java Swing实现的正则表达式测试工具，,如下代码：package

如下代码：

package cn.outofmemory.snippets.core;import java.awt.GridLayout;import java.util.regex.Matcher;import java.util.regex.Pattern;import java.util.regex.PatternSyntaxException;import javax.swing.*;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. */public class GuiDemo extends JPanel {    protected Pattern pattern;    protected Matcher m;    protected JTextField pattTF, strTF;    protected JCheckBox compiledOK;    protected JRadioButton match, find, findAll;    protected JTextField mTF;    /**     * "main program" method - construct and show     */    public static void main(String[] av) {        JFrame f = new JFrame("GuiDemo");        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        GuiDemo comp = new GuiDemo();        f.setContentPane(comp);        f.pack();        f.setLocation(200, 200);        f.setVisible(true);    }    /**     * Construct the REDemo object including its GUI     */    public GuiDemo() {        super();        JPanel top = new JPanel();        top.add(new JLabel("Pattern:", JLabel.RIGHT));        pattTF = new JTextField(20);        pattTF.getDocument().addDocumentListener(new PattListener());        top.add(pattTF);        top.add(new JLabel("Syntax OK?"));        compiledOK = new JCheckBox();        top.add(compiledOK);        ChangeListener cl = new ChangeListener() {            @Override            public void stateChanged(ChangeEvent ce) {                tryToMatch();            }        };        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));        strTF = new JTextField(20);        strTF.getDocument().addDocumentListener(new StrListener());        strPane.add(strTF);        strPane.add(new JLabel("Matches:"));        mTF = new JTextField(3);        strPane.add(mTF);        setLayout(new GridLayout(0, 1, 5, 5));        add(top);        add(strPane);        add(switchPane);    }    protected void setMatch(boolean b) {        if (b) {            mTF.setText("Yes");        } else {            mTF.setText("No");        }    }    protected void setMatch(int n) {        mTF.setText(Integer.toString(n));    }    protected void tryToCompile() {        pattern = null;        try {            pattern = Pattern.compile(pattTF.getText());            m = pattern.matcher("");            compiledOK.setSelected(true);        } catch (PatternSyntaxException ex) {            compiledOK.setSelected(false);        }    }    protected boolean tryToMatch() {        if (pattern == null) {            return false;        }        m.reset(strTF.getText());        if (match.isSelected() && m.matches()) {            setMatch(true);            return true;        }        if (find.isSelected() && m.find()) {            setMatch(true);            return true;        }        if (findAll.isSelected()) {            int i = 0;            while (m.find()) {                ++i;            }            if (i > 0) {                setMatch(i);                return true;            }        }        setMatch(false);        return false;    }    /**     * Any change to the pattern tries to compile the result.     */    class PattListener implements DocumentListener {        @Override        public void changedUpdate(DocumentEvent ev) {            tryToCompile();        }        @Override        public void insertUpdate(DocumentEvent ev) {            tryToCompile();        }        @Override        public void removeUpdate(DocumentEvent ev) {            tryToCompile();        }    }    /**     * Any change to the input string tries to match the result     */    class StrListener implements DocumentListener {        @Override        public void changedUpdate(DocumentEvent ev) {            tryToMatch();        }        @Override        public void insertUpdate(DocumentEvent ev) {            tryToMatch();        }        @Override        public void removeUpdate(DocumentEvent ev) {            tryToMatch();        }    }}