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