将毫秒转换为时间

    /**
     * 转换为时间（天,时:分:秒.毫秒）
     * @param timeMillis
     * @return
     */
    public static String formatDateTime(long timeMillis){
        long day = timeMillis/(24*60*60*1000);
        long hour = (timeMillis/(60*60*1000)-day*24);
        long min = ((timeMillis/(60*1000))-day*24*60-hour*60);
        long s = (timeMillis/1000-day*24*60*60-hour*60*60-min*60);
        long sss = (timeMillis-day*24*60*60*1000-hour*60*60*1000-min*60*1000-s*1000);
        return (day>0?day+",":"")+hour+":"+min+":"+s+"."+sss;
    }

事例：

public class Test2 {
    public static void main(String[] args) {
        Date date = new Date();

        long time = date.getTime();

        String s = DateUtils.formatDateTime(time);
        System.out.println("将毫秒转换为时间为： " + s);

    }

}

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