当前时间往后多久

public class TestDate {
    public static void main(String[] args) {
        // 根据有效天数获取失效日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss");
        Timestamp nowDate = new Timestamp(System.currentTimeMillis());
        Calendar rightNow = Calendar.getInstance();
        rightNow.setTime(nowDate);
        rightNow.add(Calendar.DAY_OF_MONTH, 10);// 当前时间往后推迟10天
        Date dt = rightNow.getTime();
        String reStr = sdf.format(dt);
        System.out.println(reStr);
        // 活动有效时间
        Calendar rightNow2 = Calendar.getInstance();
        rightNow2.setTime(nowDate);
        rightNow2.add(Calendar.MONTH, 1); // 当前时间往后推一个月
        Date dt2 = rightNow2.getTime();
        String reStr2 = sdf.format(dt2);
        System.out.println(reStr2);
    }
}

时间差

1 /**
 2      * 获取时间差
 3      * @param time1 time2 需要计算的时间
 4      * @return
 5      */
 6     public static String getTimeDeffer(String time1,String time2)
 7     {
 8         String result = "";
 9         if(StringUtils.isNotBlank(time1)&&StringUtils.isNotBlank(time2)){
10             SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
11             try {
12                 long dt1 = sdf.parse( time1 ).getTime();
13                 long dt2 = sdf.parse( time2 ).getTime();
14                 long dc = Math.abs(dt2-dt1);
16                 long seconds = dc/1000;   
17                 long date = seconds/(24*60*60);     //相差的天数   
18                 long hour = (seconds-date*24*60*60)/(60*60);//相差的小时数   
19                 long minut = (seconds-date*24*60*60-hour*60*60)/(60);//相差的分钟数
20                 long second = (seconds-date*24*60*60-hour*60*60-minut*60);//相差的秒数   
21                 return (date==0?"":(date+"天"))+(hour==0?"":(hour+"小时"))+(minut==0?"":(minut+"分"))+(second==0?"":(second+"秒"));
22             } catch (ParseException e) {
23                 e.printStackTrace();
24             }
25         }
26         return result;        
27     }