添加DocumentListener以验证多个JTextField

Question

下面给出的代码对一个JTextField进行实时验证。输入一些值到txt1启用保存按钮并删除值将重置保存按钮以禁用。我使用Netbeans作为IDE。

我的Swing应用程序有几个JTextFields。我想要做的是在检查多个JTextField的有效性后启用Save按钮。如果任何文本字段为空，则必须禁用btnSave。

有人能帮助我扩展这个程序来验证多个JTextFields吗？

public NewJFrame() { 
     initComponents(); 
     btnSave.setEnabled(false); 

     txt1.getDocument().addDocumentListener(new DocumentListener() { 
       @Override 
       public void changedUpdate(DocumentEvent e) { 

       } 

       @Override 
       public void removeUpdate(DocumentEvent e) { 
        validate(e); 
       } 

       @Override 
       public void insertUpdate(DocumentEvent e) { 
        validate(e); 
       } 

       public void validate(DocumentEvent e) { 
        String currText = ""; 
        try { 
          Document doc = (Document) e.getDocument(); 
          currText = doc.getText(0, doc.getLength()); 
        } catch (BadLocationException e1) { 
          e1.printStackTrace(); 
        } 
        if (currText.isEmpty()) { 
          Runnable doRun = new Runnable() { 
           @Override 
           public void run() { 
             isValidFromTextField1 = false; 
             validFormatterLimit(); 

           } 
          }; 
          SwingUtilities.invokeLater(doRun); 
        } else { 
          Runnable doRun = new Runnable() { 
           @Override 
           public void run() { 
             isValidFromTextField1 = true; 
             validFormatterLimit(); 

           } 
          }; 
          SwingUtilities.invokeLater(doRun); 
        } 
       } 
     }); 


     txt2.getDocument().addDocumentListener(new DocumentListener() { 
       @Override 
       public void changedUpdate(DocumentEvent e) { 

       } 

       @Override 
       public void removeUpdate(DocumentEvent e) { 
        validate(e); 
       } 

       @Override 
       public void insertUpdate(DocumentEvent e) { 
        validate(e); 
       } 

       public void validate(DocumentEvent e) { 
        String currText = ""; 
        try { 
          Document doc = (Document) e.getDocument(); 
          currText = doc.getText(0, doc.getLength()); 
        } catch (BadLocationException e1) { 
          e1.printStackTrace(); 
        } 
        if (currText.isEmpty()) { 
          Runnable doRun = new Runnable() { 
           @Override 
           public void run() { 
             isValidFromTextField2 = false; 
             validFormatterLimit(); 

           } 
          }; 
          SwingUtilities.invokeLater(doRun); 
        } else { 
          Runnable doRun = new Runnable() { 
           @Override 
           public void run() { 
             isValidFromTextField2 = true; 
             validFormatterLimit(); 

           } 
          }; 
          SwingUtilities.invokeLater(doRun); 
        } 
       } 
     }); 





    } 

    public void validFormatterLimit() { 

     if (isValidFromTextField1 == true && isValidFromTextField2 == true) { 
       btnSave.setEnabled(true); 
     } else { 
       btnSave.setEnabled(false); 
     } 

    } 

Answer 1

• 具有分裂验证

• 每个事件应当从每JComponents

  称为

• 非常简单的例子与要求的步骤

延迟（3， 5秒）Swing Timer

import java.awt.*; 
import java.awt.event.ActionEvent; 
import java.awt.event.ItemEvent; 
import java.awt.event.ItemListener; 
import java.awt.font.TextAttribute; 
import java.math.*; 
import java.text.*; 
import java.util.Map; 
import java.util.Vector; 
import javax.swing.*; 
import javax.swing.JFormattedTextField.AbstractFormatter; 
import javax.swing.JFormattedTextField.AbstractFormatterFactory; 
import javax.swing.event.*; 
import javax.swing.text.InternationalFormatter; 

public class FormatterLimit { 

    private JFrame frame = new JFrame("AbstractTextField Test"); 
    private Map attributes = (new Font("Serif", Font.BOLD, 16)).getAttributes(); 
    private JFormattedTextField textField1 = new JFormattedTextField(new Float(710.01)); 
    private JFormattedTextField textField2 = new JFormattedTextField(new Float(150.01)); 
    private Vector<Boolean> comboBoxItems = new Vector<Boolean>(); 
    private JComboBox box = new JComboBox(comboBoxItems); 
    private JButton btn = new JButton("Validations !!!"); 
    private Boolean isValidFromTextField1 = true; 
    private Boolean isValidFromTextField2 = true; 
    private Boolean isValidFromBox = true; 
    private javax.swing.Timer timer = null; 

    public FormatterLimit() { 
     attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON); 
     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; 
      } 
     }); 
     textField1.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) textField1.getValue()).doubleValue()); 
       if (t1a1 < 500) { 
        Runnable doRun = new Runnable() { 
         @Override 
         public void run() { 
          isValidFromTextField1 = false; 
          validFormatterLimit(); 
          textField1.setFont(new Font(attributes)); 
          textField1.setForeground(Color.red); 
         } 
        }; 
        SwingUtilities.invokeLater(doRun); 
       } else { 
        Runnable doRun = new Runnable() { 
         @Override 
         public void run() { 
          isValidFromTextField1 = true; 
          validFormatterLimit(); 
          textField1.setFont(new Font("Serif", Font.BOLD, 16)); 
          textField1.setForeground(Color.black); 
         } 
        }; 
        SwingUtilities.invokeLater(doRun); 
       } 
      } 
     }); 
     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() { 
          isValidFromTextField2 = false; 
          validFormatterLimit(); 
          textField2.setFont(new Font(attributes)); 
          textField2.setForeground(Color.red); 
         } 
        }; 
        SwingUtilities.invokeLater(doRun); 
       } else { 
        Runnable doRun = new Runnable() { 
         @Override 
         public void run() { 
          isValidFromTextField2 = true; 
          validFormatterLimit(); 
          textField2.setFont(new Font("Serif", Font.BOLD, 16)); 
          textField2.setForeground(Color.black); 
         } 
        }; 
        SwingUtilities.invokeLater(doRun); 
       } 
      } 
     }); 
     comboBoxItems.add(Boolean.TRUE); 
     comboBoxItems.add(Boolean.FALSE); 
     box = new JComboBox(comboBoxItems); 
     box.addItemListener(new ItemListener() { 
      @Override 
      public void itemStateChanged(ItemEvent e) { 
       if (e.getStateChange() == ItemEvent.SELECTED) { 
        if (e.getSource() == box) { 
         if (box.getSelectedItem() == (Boolean) true) { 
          isValidFromBox = true; 
          validFormatterLimit(); 
         } else { 
          isValidFromBox = false; 
          validFormatterLimit(); 
         } 
        } 
       } 
      } 
     }); 
     frame.setLayout(new GridLayout(5, 0, 5, 5)); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.add(textField1); 
     frame.add(textField2); 
     frame.add(box, BorderLayout.SOUTH); 
     frame.add(new JLabel()); 
     frame.add(btn); 
     frame.setVisible(true); 
     frame.pack(); 
     start(); 
    } 

    private void start() { 
     timer = new javax.swing.Timer(3500, updateCol()); 
     timer.setRepeats(false); 
     timer.start(); 
    } 

    public Action updateCol() { 
     return new AbstractAction("text load action") { 
      private static final long serialVersionUID = 1L; 

      @Override 
      public void actionPerformed(ActionEvent e) { 
       textField1.setValue(300); 
       textField2.setValue(8000); 
       if (box.getSelectedItem() == (Boolean) false) { 
        box.setSelectedItem((Boolean) true); 
       } else { 
        box.setSelectedItem((Boolean) false); 
       } 
      } 
     }; 
    } 

    public void validFormatterLimit(/*Boolean isValidFromTextField1, 
      * Boolean isValidFromTextField2 , Boolean isValidFromBox*/) { 
     if (isValidFromTextField1) { 
      if (isValidFromTextField2) { 
       if (isValidFromBox) { 
        btn.setEnabled(true); 
       } else { 
        btn.setEnabled(false); 
       } 
      } else { 
       btn.setEnabled(false); 
      } 
     } else { 
      btn.setEnabled(false); 
     } 
    } 


    public static void main(String args[]) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       FormatterLimit comboBoxModel = new FormatterLimit(); 
      } 
     }); 
    } 
}