Java 時間戳加減

  public static void main(String[] args){

        long curSysTime = System.currentTimeMillis();
        System.out.println(curSysTime);
        System.out.println(new Date(curSysTime));
　　　　　//減去一周
        long deadtime=curSysTime-7*24*60*60*1000L;
        System.out.println(deadtime);
        System.out.println(new Date(deadtime));
    }