java保存数字_Java：JFormattedTextField保存数字

在我的应用程序中,我想将数字(金额)输入到特定限制,因此使用了JFormattedTextField.限制为“12345678.99”,即“.”之前的8位数.和“.”之后的2.等等.这是我的实现代码,但它没有按预期结果.

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

我哪里错了？以及如何使这个工作,因为我期待它.

StanislavL建议的更新：

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

它遵守了真正的限制,但它消除了以前的数字而不是以后的数字.我的意思是在4562147896.45而不是“45”“96”不应该被淘汰.

解决方法:

甚至JFormattedTextField实现了DecimalFormat和NumberFormat,更好的是使用DocumentListener,

1)通过使用DecimalFormat或NumberFormat简单地在大数字之间跳跃不通用实现setMinimum()和setMaximum()的用户不可接受

2)默认情况下JTextComponents实现插入文本,然后任何解决方法都是如此用户不可接受的implementsJFormattedTextField与DecimalFormat或NumberFormat实现setMinimum()和setMaximum()

3)它非常舒适的使用DocumentListener允许添加任何数量,但具有突出显示的out-off范围

4)或者使用带有SpinnerNumberModel的JSpinner,可以设置Formatter和Number Instance

一起使用InternationalFormatter和DocumentListener的示例

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() {

}

}

标签：jformattedtextfield,java,swing,number-formatting

来源： https://codeday.me/bug/20190918/1810335.html