Android在代码中获取当前系统的时间并格式化

private String getTime() {    long time = System.currentTimeMillis();//long now = android.os.SystemClock.uptimeMillis();    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:SS");    Date d1 = new Date(time);    String t1 = format.format(d1);    return t1;
}