根据系统毫秒数计算年月日时分秒，只允许通过四则运算_JAVA_编程开发_程序员俱乐部

根据系统毫秒数计算年月日时分秒，只允许通过四则运算
http://yy629.iteye.com yyong629@qq.com 日期: 2012年04月25日
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看到别人写的结果不正确, 就花些时间自己做了一个.
简单测试了, 没有发现错误, 基本上应该是正确的了.
[小弟不才,也闲着蛋疼,写的比较凌乱.]

public static String myTimeStr(long timeMillis) {
    int timezone = 8;
    long totalSeconds = timeMillis / 1000;
    totalSeconds += 60 * 60 * timezone;
    int second = (int)(totalSeconds % 60);// 秒
    long totalMinutes = totalSeconds / 60;
    int minute = (int)(totalMinutes % 60);// 分
    long totalHours = totalMinutes / 60;
    int hour = (int)(totalHours % 24);// 时
    int totalDays = (int)(totalHours / 24);

    int _year = 1970;

    int year = _year + totalDays / 366;
    int month = 1;
    int day = 1;

    int diffDays;
    boolean leapYear;
    while (true) {
      int diff = (year - _year) * 365;
      diff += (year - 1) / 4 - (_year - 1) / 4;
      diff -= ((year - 1) / 100 - (_year - 1) / 100);
      diff += (year - 1) / 400 - (_year - 1) / 400;

      diffDays = totalDays - diff;

      leapYear = (year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0);
      if (!leapYear && diffDays < 365 || leapYear && diffDays < 366) {
        break;
      } else {
        year++;
      }
    }

    int[] monthDays;
    if (diffDays >= 59 && leapYear) {
      monthDays = new int[]{-1,0,31,60,91,121,152,182,213, 244, 274, 305, 335 };
    } else {
      monthDays = new int[]{-1,0,31,59,90,120,151,181,212, 243, 273, 304, 334 };
    }
    for (int i = monthDays.length - 1; i >= 1; i--) {
      if (diffDays >= monthDays[i]) {
        month = i;
        day = diffDays - monthDays[i] + 1;
        break;
      }
    }

    return year + "-" + month + "-" + day + " " + hour + ":" + minute + ":" + second;

  }

// 以下是测试代码
  public static void main(String[] args) throws Exception {
    long curr = System.currentTimeMillis(); // *10 
    for (long i = 0; i <= curr; i += 1000L * 60 * 30) {//*60*12
      String a = jdkTimeStr(i);
      String b = myTimeStr(i);
      if (!a.equals(b)) {
        System.out.println(">>>>>>>>>　　　　　　　　　　" + i + ": " + a + "   " + b);
        //        break;
      } else {
        //System.out.println(i + ": " + a + "   " + b);
      }
    }
  }

  public static String jdkTimeStr(long timeMillis) { // 通过jdk日期类获取
    Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT+8"));
    c.setTimeInMillis(timeMillis);
    return c.get(Calendar.YEAR) + "-" + (c.get(Calendar.MONTH) + 1) + "-" + c.get(Calendar.DAY_OF_MONTH) + " "
        + c.get(Calendar.HOUR_OF_DAY) + ":" + c.get(Calendar.MINUTE) + ":" + c.get(Calendar.SECOND);
  }