我有一个扩展的文本字段,javax.swing.JTextField
也有像这样的文档侦听器
public class MyTetField extends javax.swing.JTextFiled{
public MyTextField(){
super();
// Document listener to check mandatory functionality
getDocument().addDocumentListener(new javax.swing.event.DocumentListener() {
/**
* If the text is changed then this event will be fired.
*/
public void changedUpdate(javax.swing.event.DocumentEvent e) {
}
/**
* If some value is removed then this event is fired.
*/
public void removeUpdate(javax.swing.event.DocumentEvent e) {
}
/**
* If some value is auto set, this event will be called
* @param e The value change event
*/
public void insertUpdate(javax.swing.event.DocumentEvent e) {
if (getText().trim().equals("")){
setBorder(javax.swing.BorderFactory.createLineBorder(java.awt.Color.RED));
}else{
setBorder(javax.swing.BorderFactory.createLineBorder(java.awt.Color.GRAY));
}
}
});
}
}
现在我想要另一个文本字段说MyTextField1
扩展MyTextField
它应该有这个强制检查,并且在检查强制字段之后从数据库中获取一些信息,如果给出了一些值。我不想在其中编写相同的文档侦听器代码。是否可以扩展我们添加的文档侦听器MyTextField
或者我应该选择焦点侦听器?