java 定义三分钟之前的时间

public String getCurrentTime(){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   Calendar beforeTime = Calendar.getInstance();
   beforeTime.add(Calendar.MINUTE, -3);// 3分钟之前的时间
   Date beforeD = beforeTime.getTime();
   String time = sdf.format(beforeD);
return time;
}