This program demonstrates formatting numbers under various locales.
/*
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.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Locale;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;
/**
* This program demonstrates formatting numbers under various locales.
*
* @version 1.13 2007-07-25
* @author Cay Horstmann
*/
public class NumberFormatTest {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame frame = new NumberFormatFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
/**
* This frame contains radio buttons to select a number format, a combo box to
* pick a locale, a text field to display a formatted number, and a button to
* parse the text field contents.
*/
class NumberFormatFrame extends JFrame {
public NumberFormatFrame() {
setTitle("NumberFormatTest");
setLayout(new GridBagLayout());
ActionListener listener = new ActionListener() {
public void actionPerformed(ActionEvent event) {
updateDisplay();
}
};
JPanel p = new JPanel();
addRadioButton(p, numberRadioButton, rbGroup, listener);
addRadioButton(p, currencyRadioButton, rbGroup, listener);
addRadioButton(p, percentRadioButton, rbGroup, listener);
add(new JLabel("Locale:"), new GBC(0, 0).setAnchor(GBC.EAST));
add(p, new GBC(1, 1));
add(parseButton, new GBC(0, 2).setInsets(2));
add(localeCombo, new GBC(1, 0).setAnchor(GBC.WEST));
add(numberText, new GBC(1, 2).setFill(GBC.HORIZONTAL));
locales = (Locale[]) NumberFormat.getAvailableLocales().clone();
Arrays.sort(locales, new Comparator<Locale>() {
public int compare(Locale l1, Locale l2) {
return l1.getDisplayName().compareTo(l2.getDisplayName());
}
});
for (Locale loc : locales)
localeCombo.addItem(loc.getDisplayName());
localeCombo.setSelectedItem(Locale.getDefault().getDisplayName());
currentNumber = 123456.78;
updateDisplay();
localeCombo.addActionListener(listener);
parseButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
String s = numberText.getText().trim();
try {
Number n = currentNumberFormat.parse(s);
if (n != null) {
currentNumber = n.doubleValue();
updateDisplay();
} else {
numberText.setText("Parse error: " + s);
}
} catch (ParseException e) {
numberText.setText("Parse error: " + s);
}
}
});
pack();
}
/**
* Adds a radio button to a container.
*
* @param p
* the container into which to place the button
* @param b
* the button
* @param g
* the button group
* @param listener
* the button listener
*/
public void addRadioButton(Container p, JRadioButton b, ButtonGroup g, ActionListener listener) {
b.setSelected(g.getButtonCount() == 0);
b.addActionListener(listener);
g.add(b);
p.add(b);
}
/**
* Updates the display and formats the number according to the user settings.
*/
public void updateDisplay() {
Locale currentLocale = locales[localeCombo.getSelectedIndex()];
currentNumberFormat = null;
if (numberRadioButton.isSelected())
currentNumberFormat = NumberFormat.getNumberInstance(currentLocale);
else if (currencyRadioButton.isSelected())
currentNumberFormat = NumberFormat.getCurrencyInstance(currentLocale);
else if (percentRadioButton.isSelected())
currentNumberFormat = NumberFormat.getPercentInstance(currentLocale);
String n = currentNumberFormat.format(currentNumber);
numberText.setText(n);
}
private Locale[] locales;
private double currentNumber;
private JComboBox localeCombo = new JComboBox();
private JButton parseButton = new JButton("Parse");
private JTextField numberText = new JTextField(30);
private JRadioButton numberRadioButton = new JRadioButton("Number");
private JRadioButton currencyRadioButton = new JRadioButton("Currency");
private JRadioButton percentRadioButton = new JRadioButton("Percent");
private ButtonGroup rbGroup = new ButtonGroup();
private NumberFormat currentNumberFormat;
}
/*
* 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/>.
*/
/*
* GBC - A convenience class to tame the GridBagLayout
*
* Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)
*
* 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 2 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, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* This class simplifies the use of the GridBagConstraints class.
*/
class GBC extends GridBagConstraints {
/**
* Constructs a GBC with a given gridx and gridy position and all other grid
* bag constraint values set to the default.
*
* @param gridx
* the gridx position
* @param gridy
* the gridy position
*/
public GBC(int gridx, int gridy) {
this.gridx = gridx;
this.gridy = gridy;
}
/**
* Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all
* other grid bag constraint values set to the default.
*
* @param gridx
* the gridx position
* @param gridy
* the gridy position
* @param gridwidth
* the cell span in x-direction
* @param gridheight
* the cell span in y-direction
*/
public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
this.gridx = gridx;
this.gridy = gridy;
this.gridwidth = gridwidth;
this.gridheight = gridheight;
}
/**
* Sets the anchor.
*
* @param anchor
* the anchor value
* @return this object for further modification
*/
public GBC setAnchor(int anchor) {
this.anchor = anchor;
return this;
}
/**
* Sets the fill direction.
*
* @param fill
* the fill direction
* @return this object for further modification
*/
public GBC setFill(int fill) {
this.fill = fill;
return this;
}
/**
* Sets the cell weights.
*
* @param weightx
* the cell weight in x-direction
* @param weighty
* the cell weight in y-direction
* @return this object for further modification
*/
public GBC setWeight(double weightx, double weighty) {
this.weightx = weightx;
this.weighty = weighty;
return this;
}
/**
* Sets the insets of this cell.
*
* @param distance
* the spacing to use in all directions
* @return this object for further modification
*/
public GBC setInsets(int distance) {
this.insets = new Insets(distance, distance, distance, distance);
return this;
}
/**
* Sets the insets of this cell.
*
* @param top
* the spacing to use on top
* @param left
* the spacing to use to the left
* @param bottom
* the spacing to use on the bottom
* @param right
* the spacing to use to the right
* @return this object for further modification
*/
public GBC setInsets(int top, int left, int bottom, int right) {
this.insets = new Insets(top, left, bottom, right);
return this;
}
/**
* Sets the internal padding
*
* @param ipadx
* the internal padding in x-direction
* @param ipady
* the internal padding in y-direction
* @return this object for further modification
*/
public GBC setIpad(int ipadx, int ipady) {
this.ipadx = ipadx;
this.ipady = ipady;
return this;
}
}
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