java - Detecting backspace key press -

is there way detect when backspace key on keyboard has been pressed, using document filter? the following edited code extract here

for example

public class intfilter extends documentfilter {     boolean truefalse = true;     public void insertstring(documentfilter.filterbypass fb, int offset,                              string string, attributeset attr)             throws badlocationexception {          stringbuffer buffer = new stringbuffer(string);         (int = buffer.length() - 1; >= 0; i--) {             char ch = buffer.charat(i);             if (!character.isdigit(ch)) {                 buffer.deletecharat(i);                 truefalse = false;             }             /*             else if (backspace pressed)             {                 truefalse = true;             }             */             else{                 truefalse = true;             }         }         super.insertstring(fb, offset, buffer.tostring(), attr);     }      public void replace(documentfilter.filterbypass fb,                         int offset, int length, string string, attributeset attr) throws badlocationexception {         if (length > 0) fb.remove(offset, length);         insertstring(fb, offset, string, attr);     } } 

pressing backspace key won't trigger insertstring() method. should rather trigger remove() method (only when text removed, not case when caret @ beginning of text example).

but can detect keystroke using keylistener (doc). here's how detect backspace key:

public class keyeventdemo implements keylistener {      /** handle key typed event text field. */     public void keytyped(keyevent e) {}      /** handle key-pressed event text field. */     public void keypressed(keyevent e) {}      /** handle key-released event text field. */     public void keyreleased(keyevent e) {         if(e.getkeycode()==keyevent.vk_back_space){              // something...         }     }  }