如何在Android应用层中制作一个LED指示灯效果

public class LEDActivity extends Activity implements View.OnClickListener {
private static final String TAG = "LED";
Button mLedTest;
int mLedStatus = 0;
private final int mLedColorRed = 0xFFFF0000;

final byte[] LIGHT_ON = { '2', '5', '5' };
final byte[] LIGHT_OFF = { '0' };
private final int RED = 0;
private int color = RED;
String RED_LED_DEV = " /sys/class/leds/torch/brightness";

public void onCreate(Bundle paramBundle) {
  super.onCreate(paramBundle);
  setContentView(R.layout.led_test);

  mLedTest = ((Button)findViewById(R.id.ledcolor));
  mLedTest.setOnClickListener(this);

 //  setledlightcolor(color);
 //  mLedTest.setTextColor(mLedColorRed);
 //  mLedTest.setText("RED"); 
 //  mLedStatus = 1;
 }

 public void onClick(View v) {
 Log.d("LEDActivity", "---onClick---mLedStatus=" + mLedStatus);
 switch (v.getId()) {
 case R.id.ledcolor:
 if(mLedStatus == 0) {
 mLedTest.setText("开");
 mLedStatus = 1
 }else if(mLedStatus == 1) {
   mLedTest.setText("关");
   mLedStatus = 0;
 }
 break;
 }
 }

 @Override
public void finish() {
  setledlightcolor(-1);
  super.finish();
}
private void setledlightcolor(int color) {
  logd("set:" + color);
  boolean red = false;
  switch (color) {
  case RED:
    red = true;
    break;
  default:
    break;
  }
  try {
    FileOutputStream foRed = new FileOutputStream(RED_LED_DEV);
    Log.d(TAG, "foRed" + foRed);
    fRed.write(red ? LIGHT_ON : LIGHT_OFF);
    fRed.close();
  } catch (Exception e) {
    loge(e);
  }
}
void logd(Object d) {
  Log.d(TAG, "" + d);
}
void loge(Object e) {
  Log.e(TAG, "" + e);
}
}