Java tutorial
/* This program is a part of the companion code for Core Java 8th ed. (http://horstmann.com/corejava) 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 (at your option) 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. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ import java.awt.BorderLayout; import java.awt.EventQueue; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.net.MalformedURLException; import java.net.URL; import java.text.DateFormat; import java.text.NumberFormat; import java.text.ParseException; import java.util.Arrays; import java.util.Date; import java.util.StringTokenizer; import javax.swing.InputVerifier; import javax.swing.JButton; import javax.swing.JComponent; import javax.swing.JFormattedTextField; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.DefaultFormatter; import javax.swing.text.DocumentFilter; import javax.swing.text.InternationalFormatter; import javax.swing.text.MaskFormatter; /** * A program to test formatted text fields * @version 1.02 2007-06-12 * @author Cay Horstmann */ public class FormatTest { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { FormatTestFrame frame = new FormatTestFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }); } } /** * A frame with a collection of formatted text fields and a button that displays the field values. */ class FormatTestFrame extends JFrame { public FormatTestFrame() { setTitle("FormatTest"); setSize(WIDTH, HEIGHT); JPanel buttonPanel = new JPanel(); okButton = new JButton("Ok"); buttonPanel.add(okButton); add(buttonPanel, BorderLayout.SOUTH); mainPanel = new JPanel(); mainPanel.setLayout(new GridLayout(0, 3)); add(mainPanel, BorderLayout.CENTER); JFormattedTextField intField = new JFormattedTextField(NumberFormat.getIntegerInstance()); intField.setValue(new Integer(100)); addRow("Number:", intField); JFormattedTextField intField2 = new JFormattedTextField(NumberFormat.getIntegerInstance()); intField2.setValue(new Integer(100)); intField2.setFocusLostBehavior(JFormattedTextField.COMMIT); addRow("Number (Commit behavior):", intField2); JFormattedTextField intField3 = new JFormattedTextField( new InternationalFormatter(NumberFormat.getIntegerInstance()) { protected DocumentFilter getDocumentFilter() { return filter; } private DocumentFilter filter = new IntFilter(); }); intField3.setValue(new Integer(100)); addRow("Filtered Number", intField3); JFormattedTextField intField4 = new JFormattedTextField(NumberFormat.getIntegerInstance()); intField4.setValue(new Integer(100)); intField4.setInputVerifier(new FormattedTextFieldVerifier()); addRow("Verified Number:", intField4); JFormattedTextField currencyField = new JFormattedTextField(NumberFormat.getCurrencyInstance()); currencyField.setValue(new Double(10)); addRow("Currency:", currencyField); JFormattedTextField dateField = new JFormattedTextField(DateFormat.getDateInstance()); dateField.setValue(new Date()); addRow("Date (default):", dateField); DateFormat format = DateFormat.getDateInstance(DateFormat.SHORT); format.setLenient(false); JFormattedTextField dateField2 = new JFormattedTextField(format); dateField2.setValue(new Date()); addRow("Date (short, not lenient):", dateField2); try { DefaultFormatter formatter = new DefaultFormatter(); formatter.setOverwriteMode(false); JFormattedTextField urlField = new JFormattedTextField(formatter); urlField.setValue(new URL("http://java.sun.com")); addRow("URL:", urlField); } catch (MalformedURLException e) { e.printStackTrace(); } try { MaskFormatter formatter = new MaskFormatter("###-##-####"); formatter.setPlaceholderCharacter('0'); JFormattedTextField ssnField = new JFormattedTextField(formatter); ssnField.setValue("078-05-1120"); addRow("SSN Mask:", ssnField); } catch (ParseException exception) { exception.printStackTrace(); } JFormattedTextField ipField = new JFormattedTextField(new IPAddressFormatter()); ipField.setValue(new byte[] { (byte) 130, 65, 86, 66 }); addRow("IP Address:", ipField); } /** * Adds a row to the main panel. * @param labelText the label of the field * @param field the sample field */ public void addRow(String labelText, final JFormattedTextField field) { mainPanel.add(new JLabel(labelText)); mainPanel.add(field); final JLabel valueLabel = new JLabel(); mainPanel.add(valueLabel); okButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { Object value = field.getValue(); Class<?> cl = value.getClass(); String text = null; if (cl.isArray()) { if (cl.getComponentType().isPrimitive()) { try { text = Arrays.class.getMethod("toString", cl).invoke(null, value).toString(); } catch (Exception ex) { // ignore reflection exceptions } } else text = Arrays.toString((Object[]) value); } else text = value.toString(); valueLabel.setText(text); } }); } public static final int WIDTH = 500; public static final int HEIGHT = 250; private JButton okButton; private JPanel mainPanel; } /** * A filter that restricts input to digits and a '-' sign. */ class IntFilter extends DocumentFilter { public void insertString(FilterBypass fb, int offset, String string, AttributeSet attr) throws BadLocationException { StringBuilder builder = new StringBuilder(string); for (int i = builder.length() - 1; i >= 0; i--) { int cp = builder.codePointAt(i); if (!Character.isDigit(cp) && cp != '-') { builder.deleteCharAt(i); if (Character.isSupplementaryCodePoint(cp)) { i--; builder.deleteCharAt(i); } } } super.insertString(fb, offset, builder.toString(), attr); } public void replace(FilterBypass fb, int offset, int length, String string, AttributeSet attr) throws BadLocationException { if (string != null) { StringBuilder builder = new StringBuilder(string); for (int i = builder.length() - 1; i >= 0; i--) { int cp = builder.codePointAt(i); if (!Character.isDigit(cp) && cp != '-') { builder.deleteCharAt(i); if (Character.isSupplementaryCodePoint(cp)) { i--; builder.deleteCharAt(i); } } } string = builder.toString(); } super.replace(fb, offset, length, string, attr); } } /** * A verifier that checks whether the content of a formatted text field is valid. */ class FormattedTextFieldVerifier extends InputVerifier { public boolean verify(JComponent component) { JFormattedTextField field = (JFormattedTextField) component; return field.isEditValid(); } } /** * A formatter for 4-byte IP addresses of the form a.b.c.d */ class IPAddressFormatter extends DefaultFormatter { public String valueToString(Object value) throws ParseException { if (!(value instanceof byte[])) throw new ParseException("Not a byte[]", 0); byte[] a = (byte[]) value; if (a.length != 4) throw new ParseException("Length != 4", 0); StringBuilder builder = new StringBuilder(); for (int i = 0; i < 4; i++) { int b = a[i]; if (b < 0) b += 256; builder.append(String.valueOf(b)); if (i < 3) builder.append('.'); } return builder.toString(); } public Object stringToValue(String text) throws ParseException { StringTokenizer tokenizer = new StringTokenizer(text, "."); byte[] a = new byte[4]; for (int i = 0; i < 4; i++) { int b = 0; if (!tokenizer.hasMoreTokens()) throw new ParseException("Too few bytes", 0); try { b = Integer.parseInt(tokenizer.nextToken()); } catch (NumberFormatException e) { throw new ParseException("Not an integer", 0); } if (b < 0 || b >= 256) throw new ParseException("Byte out of range", 0); a[i] = (byte) b; } if (tokenizer.hasMoreTokens()) throw new ParseException("Too many bytes", 0); return a; } }