代码语言：javascript复制
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();
}
}
}</pre> 
