获取组合键

@Overridepublic void keyPressed(KeyEvent evt) {         if (evt.getKeyCode()==KeyEvent.VK_CONTROL) { ctrl  = true; }    else if (evt.getKeyCode()==KeyEvent.VK_SHIFT)   { shift = true; }    else if (evt.getKeyCode()==KeyEvent.VK_ALT)     { alt   = true; }    else {        keyHit = KeyEvent.getKeyText( evt.getKeyCode() );        System.out.println("Key Hit is "+keyHit);    }    processLocalKeyEvent(evt);}@Overridepublic void keyReleased(KeyEvent evt) {    if (evt.isControlDown() && keyHit != "") ctrl  = true;    if (evt.isAltDown()     && keyHit != "") alt   = true;    if (evt.isShiftDown()   && keyHit != "") shift = true;    if (ctrl)  sb.append("Ctrl");    if (shift) sb.append("Shift");       if (alt)   sb.append("Alt");     if (!ctrl && !shift && !alt) {        sb.append(keyHit);    } else {        sb.append("_"+keyHit);    }    if (ctrl || shift || alt) {        Thread thread = new Thread();        try { thread.sleep(300); rfbProto.capture();        } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace();        }    } else if ((ctrl || shift || alt) && keyHit=="") {        rfbProto.capture();    } else if ((!ctrl || !shift || !alt) && keyHit!="") {        rfbProto.capture();    }    ctrl  = false;    shift = false;    alt   = false;    keyHit = "";    sb = new StringBuffer();    processLocalKeyEvent(evt);}