JTextField加DocumentListener监听

DocumentListener textChangeListener=new DocumentListener() {protected void changeFilter(DocumentEvent event) {javax.swing.text.Document document = event.getDocument();try {String text=document.getText(0, document.getLength());   System.out.println(text);} catch (Exception ex) {                ex.printStackTrace();                System.err.println(ex);}}public void changedUpdate(DocumentEvent e) {changeFilter(e);}public void insertUpdate(DocumentEvent e) {changeFilter(e);}public void removeUpdate(DocumentEvent e) {changeFilter(e);}};myJTextField.getDocument().addDocumentListener(textChangeListener);