常用Java代码

Java基础

1、毫秒数转时间段

/**
     *
     * @param 要转换的毫秒数
     * @return 该毫秒数转换为 * days * hours * minutes * seconds 后的格式
     * @author fy.zhang
     */
    public String formatDuring(long mss){
     long days = mss / (1000*60*60*24);
     long hours = (mss % (1000*60*60*24)) / (1000*60*60);
     long minutes = (mss % (1000*60*60)) / (1000*60);
     long seconds = (mss % (1000*60)) /1000;
     return (days>0?(days+"天 "):"")
            +(hours>0?(hours+"小时"):"")
            +(minutes>0?(minutes+"分"):"")
            +(seconds>0?(seconds+"秒"):"");
   }
    public String formatDuring(Date begin, Date end) {
        return formatDuring(end.getTime() - begin.getTime());
    }

2、SimpleDateFormat 格式

SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");