/**
 *  时间戳转日期
 *  @explain
 *  @param timstanp 时间戳可以为String类型,也可以为long类型
 *  @return yyyy-MM-dd HH:mm:ss  格式字符串
 *
 */

public static String timestampToDate(Object timestamp){
    long sjc = 0;
    String dateStr = "";
    if(timestamp instanceof String)
        sjc =Long.parseLong((String)timestamp);
    else if(timestamp instanceof Long)
        sjc =(Long)timestamp;
    else
        return dateStr;


    Date date = new Date(sjc);
    SimpleDateFomart sdf = new SimpleDateFomart("yyyy-MM-dd HH:mm:ss");
    dateStr =sdf.format(date);
    return dateStr;
 
}

Java 获取时间戳三种方式

1. System.currentTimeMills()

2. new Date().getTime()

3. Calendar.getInstance().getTimeMillis()