在Java中将常规日期转换为Julian Date，反之亦然 [英] Convert a Regular Date to Julian Date and vice versa in Java

问题描述

以下是需要相同转换的代码：

  public int convertToJulian（String unformattedDate）
 {
 / *未格式化日期：ddmmyyyy * / 
 int resultJulian = 0; 
 if（unformattedDate.length（）> 0）
 {
 / *几个月* / 
 int [] monthValues = {31,28,31,30,31 ，30,31,31,30,31,30,31}; 
 
字符串dayS，monthS，yearS; 
 dayS = unformattedDate.substring（0,2）; 
 monthS = unformattedDate.substring（3，5）; 
 yearS = unformattedDate.substring（6，10）; 
 
 / *转换为整数* / 
 int day = Integer.valueOf（dayS）; 
 int month = Integer.valueOf（monthS）; 
 int year = Integer.valueOf（yearS）; 
 
 //闰年检查
如果（年％4 == 0）
 {
 monthValues [1] = 29; 
} 
 //开始构建朱利安日期
 String julianDate =1; 
 //年份的最后两位数：2012 ==> 12 
 julianDate + = yearS.substring（2,4）; 
 
 int julianDays = 0; （int i = 0; i< month-1; i ++）
 {
 julianDays + = monthValues [i]; 
 
} 
 julianDays + = day; 
 
 if（String.valueOf（julianDays）.length（）< 2）
 {
 julianDate + =00; 
} 
 if（String.valueOf（julianDays）.length（）< 3）
 {
 julianDate + =0; 
} 
 
 julianDate + = String.valueOf（julianDays）; 
 resultJulian = Integer.valueOf（julianDate）; 
} 
 return resultJulian; 
} 
  

此代码将01.01.2013转换为113001

我想做的是将朱利安日期转换为常规日期，而不需要时间细节。
例如：朱利安日期是113029 ==>定期日期29.01.2013

请给我你如何做的想法。

谢谢。

解决方案

如果你想要113029 ==> 29.01.2013 try

  String j =113029; 
 Date date = new SimpleDateFormat（Myydd）。parse（j）; 
 String g = new SimpleDateFormat（dd.MM.yyyy）。format（date）; 
 System.out.println（g）; 
  

输出

  29.01.2013 
  

I've written a simple code that converts a regular date to Julian date.

Here's the code for those who need the same conversion:

    public int convertToJulian(String unformattedDate)
    {
    /*Unformatted Date: ddmmyyyy*/
    int resultJulian = 0;
    if(unformattedDate.length() > 0)
    {
     /*Days of month*/
     int[] monthValues = {31,28,31,30,31,30,31,31,30,31,30,31};

     String dayS, monthS, yearS;
     dayS = unformattedDate.substring(0,2);
     monthS = unformattedDate.substring(3, 5);
     yearS = unformattedDate.substring(6, 10);

     /*Convert to Integer*/
     int day = Integer.valueOf(dayS);
     int month = Integer.valueOf(monthS);
     int year = Integer.valueOf(yearS); 

         //Leap year check
         if(year % 4 == 0)
         {
          monthValues[1] = 29;    
         }
         //Start building Julian date
         String julianDate = "1";
         //last two digit of year: 2012 ==> 12
         julianDate += yearS.substring(2,4);

         int julianDays = 0;
         for (int i=0; i < month-1; i++)
         {
          julianDays += monthValues[i];
         }
         julianDays += day;

             if(String.valueOf(julianDays).length() < 2)
             {
              julianDate += "00";
             }
             if(String.valueOf(julianDays).length() < 3)
             {
              julianDate += "0";
             }

        julianDate += String.valueOf(julianDays);
    resultJulian =  Integer.valueOf(julianDate);    
 }
 return resultJulian;
}

This code converts 01.01.2013 to 113001

What I want to do is to convert a Julian date to regular date without time details. For example: Julian date is 113029 ==> Regular date 29.01.2013

Please give me your ideas on how to do it.

Thanks.

解决方案

If you want 113029 ==> 29.01.2013 try

    String j = "113029";
    Date date = new SimpleDateFormat("Myydd").parse(j);
    String g = new SimpleDateFormat("dd.MM.yyyy").format(date);
    System.out.println(g);

output

29.01.2013

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