问题
In my application I want to input numbers (amounts) to a specific limit, and hence have used JFormattedTextField. Limit like \"12345678.99\" i.e. 8 digits before \".\" and 2 after \".\" or so on. This is my implementation code, but it doesn\'t result as expected.
startBalTxt.setFormatterFactory(new javax.swing.text.DefaultFormatterFactory(new javax.swing.text.NumberFormatter(new java.text.DecimalFormat(\"########.##\"))));
startBalTxt.setText(resourceMap.getString(\"startBalTxt.text\")); // NOI18N
startBalTxt.setFont(Utility.getTextFont());
startBalTxt.setName(\"startBalTxt\"); // NOI18N
INPUT RESULT
\"12345678905.99\" => \"12345678906\" ==> Should give \"12345678.99\" or \"12345679.99\"
\"12345678.555\" => \"12345678.56\" ==> CORRECT
\"1234567890123456\" => \"1234567890123456\" ==> Absolutely wrong in all aspects
Where am I going wrong ? And how to make this working as I am expecting it.
UPDATIONS AS PER SUGGESTED by StanislavL :
numberFormat = (DecimalFormat) DecimalFormat.getNumberInstance();
numberFormat.setMaximumFractionDigits(2);
numberFormat.setMaximumIntegerDigits(8);
numberFormat.setMinimumFractionDigits(0);
numberFormat.setMinimumIntegerDigits(2);
nfr = new NumberFormatter(numberFormat);
initComponents();
myParent = parent;
this.startBalTxt.setFormatterFactory(new javax.swing.text.DefaultFormatterFactory(nfr));
Results -> 4562147896.45 == > 62,147,896.45
Its obeying the limit that\'s true, but its eliminating previous numbers instead of later. I mean in 4562147896.45 instead of \"45\" \"96\" shouldn\'t be eliminated.
回答1:
even JFormattedTextField implements DecimalFormat and NumberFormat, better would be use DocumentListener,
1) its not good jumping betweens Big Figures by using DecimalFormat or NumberFormat simple User-non-Acceptable by implements setMinimum() and setMaximum()
2) JTextComponents by default implements insert the text, then any workaround is so User-non-Acceptable by implementsJFormattedTextField with DecimalFormat orNumberFormat by implements setMinimum() and setMaximum()
3) its very confortable je use DocumentListener allows add any amount, but with highlighting out-off range
4) or use JSpinner with SpinnerNumberModel, there is posible to set Formatter as for Number Instance
example for InternationalFormatter and DocumentListener together
import java.awt.*;
import java.awt.font.TextAttribute;
import java.math.*;
import java.text.*;
import java.util.Map;
import javax.swing.*;
import javax.swing.JFormattedTextField.*;
import javax.swing.event.*;
import javax.swing.text.InternationalFormatter;
public class DocumentListenerAdapter {
public static void main(String args[]) {
JFrame frame = new JFrame("AbstractTextField Test");
final JFormattedTextField textField1 = new JFormattedTextField(new Float(10.01));
textField1.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
formatter.setMinimum(0.0);
formatter.setMaximum(1000.00);
return formatter;
}
});
final Map attributes = (new Font("Serif", Font.BOLD, 16)).getAttributes();
attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);
final JFormattedTextField textField2 = new JFormattedTextField(new Float(10.01));
textField2.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
//formatter.setMinimum(0.0);
//formatter.setMaximum(1000.00);
return formatter;
}
});
textField2.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void insertUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void removeUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
private void printIt(DocumentEvent documentEvent) {
DocumentEvent.EventType type = documentEvent.getType();
double t1a1 = (((Number) textField2.getValue()).doubleValue());
if (t1a1 > 1000) {
Runnable doRun = new Runnable() {
@Override
public void run() {
textField2.setFont(new Font(attributes));
textField2.setForeground(Color.red);
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
textField2.setFont(new Font("Serif", Font.BOLD, 16));
textField2.setForeground(Color.black);
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(textField1, BorderLayout.NORTH);
frame.add(textField2, BorderLayout.SOUTH);
frame.setVisible(true);
frame.pack();
}
private DocumentListenerAdapter() {
}
}
回答2:
Pass DecimalFormat to the JFormattedTextField constructor. It has following methods
setMaximumIntegerDigits
setMinimumIntegerDigits
setMaximumFractionDigits
setMinimumFractionDigits
来源：https://stackoverflow.com/questions/8572948/java-jformattedtextfield-saving-numbers