のJava SwingのDocumentFilterは

Question

Click here to show the gif

DocumentFilter df = new DocumentFilter(){ 
@Override 
public void insertString(DocumentFilter.FilterBypass fb, int offset,String string, AttributeSet attr) throws BadLocationException { 
    super.insertString(fb, offset, string.toUpperCase(), attr); 
} 

@Override 
public void replace(DocumentFilter.FilterBypass fb, int offset, int length,String text, AttributeSet attrs) throws BadLocationException { 
    super.insertString(fb, offset, text.toUpperCase(), attrs); 
} 
}; 


txtCognome.setText(""); 
documentCognome.setDocumentFilter(dff); 

問題があります。選択されたテキストは削除されずに残ります（上のgifを見てください）。

Answer 1

public void replace(DocumentFilter.FilterBypass fb, int offset, int length,String text, AttributeSet attrs) throws BadLocationException { 
    super.insertString(fb, offset, text.toUpperCase(), attrs); 

replace（）メソッドをオーバーライドしているため、super.replace(...)を呼び出す必要があります。

Answer 2

CustomLengthTextField textField = new CustomLengthTextField(-1, true); 

カスタムのTextField

import java.awt.KeyboardFocusManager; 
import javax.swing.InputVerifier; 
import javax.swing.JTextField; 
import javax.swing.text.AbstractDocument; 
import javax.swing.text.AttributeSet; 
import javax.swing.text.BadLocationException; 
import javax.swing.text.DocumentFilter; 
import javax.swing.text.DocumentFilter.FilterBypass; 

/** 
* 
* @author Igor 
*/ 
public class CustomLengthTextField extends JTextField { 

    protected boolean upper = false; 
    protected int maxlength = 0; 

    public CustomLengthTextField() { 
     this(-1); 
    } 

    public CustomLengthTextField(int length, boolean upper) { 
     this(length, upper, null); 
    } 

    public CustomLengthTextField(int length, InputVerifier inpVer) { 
     this(length, false, inpVer); 
    } 

    /** 
    * 
    * @param length - maksimalan length 
    * @param upper - turn it to upercase 
    * @param inpVer - InputVerifier 
    */ 
    public CustomLengthTextField(int length, boolean upper, InputVerifier inpVer) { 
     super(); 
     this.maxlength = length; 
     this.upper = upper; 
     if (length > 0) { 
      AbstractDocument doc = (AbstractDocument) getDocument(); 
      doc.setDocumentFilter(new DocumentSizeFilter()); 
     } 
     setInputVerifier(inpVer); 
    } 

    public CustomLengthTextField(int length) { 
     this(length, false); 
    } 

    public void setMaxLength(int length) { 
     this.maxlength = length; 
    } 

    class DocumentSizeFilter extends DocumentFilter { 

     public void insertString(FilterBypass fb, int offs, String str, AttributeSet a) 
       throws BadLocationException { 

      //This rejects the entire insertion if it would make 
      //the contents too long. Another option would be 
      //to truncate the inserted string so the contents 
      //would be exactly maxCharacters in length. 
      if ((fb.getDocument().getLength() + str.length()) <= maxlength) { 
       super.insertString(fb, offs, str, a); 
      } 
     } 

     public void replace(FilterBypass fb, int offs, 
       int length, 
       String str, AttributeSet a) 
       throws BadLocationException { 

      if (upper) { 
       str = str.toUpperCase(); 
      } 

      //This rejects the entire replacement if it would make 
      //the contents too long. Another option would be 
      //to truncate the replacement string so the contents 
      //would be exactly maxCharacters in length. 
      int charLength = fb.getDocument().getLength() + str.length() - length; 

      if (charLength <= maxlength) { 
       super.replace(fb, offs, length, str, a); 
       if (charLength == maxlength) { 
        focusNextComponent(); 
       } 
      } else { 
       focusNextComponent(); 
      } 
     } 

     private void focusNextComponent() { 
      if (CustomLengthTextField.this == KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner()) { 
       KeyboardFocusManager.getCurrentKeyboardFocusManager().focusNextComponent(); 
      } 
     } 
    } 
}