Java：日期時間轉換

Question

我有一個日期格式，如「SA25MAY」;我需要將它轉換爲日期時間變量，然後我想在其中添加一天。然後我需要以相同的格式返回答案。請做一些要緊的

try { 
    String str_date = "SA25MAY"; 
    DateFormat formatter; 
    Date date; 
    formatter = new SimpleDateFormat("ddd-dd-MMM"); 
    date = (Date) formatter.parse(str_date); 
    System.out.println("Today is " + date); 
} catch (Exception e) { 
    e.printStackTrace(); 
} 

錯誤：

java.text.ParseException: Unparseable date: "SA25MAY" 
at java.text.DateFormat.parse(DateFormat.java:337) 
at javadatatable.JavaDataTable.main(JavaDataTable.java:29) 

在這裏，我不知道如何解決這個問題。

Answer 1

如果因閏年（2月29日）而知道年份，則只能添加一天。

如果當年是當年，以下解決方案應該做的工作：

對於 「SA25MAY」：

try { 
    String str_date = "SA25MAY"; 

    // remove SA 
    str_date = str_date.replaceFirst("..", ""); 

    // add current year 
    Calendar c = Calendar.getInstance(); 
    str_date = c.get(Calendar.YEAR) + str_date; 

    // parse date 
    Date date; 
    SimpleDateFormat formatter = new SimpleDateFormat("yyyyddMMM"); 
    date = formatter.parse(str_date); 
    System.out.println("Today is " + date); 

    // add day 
    c.setTime(date); 
    c.add(Calendar.DATE, 1); 

    // rebuild the old pattern with the new date 
    SimpleDateFormat formatter2 = new SimpleDateFormat("EEEddMMM"); 
    String tomorrow = formatter2.format(c.getTime()); 
    tomorrow = tomorrow.toUpperCase(); 
    tomorrow = tomorrow.substring(0, 2) + tomorrow.substring(3); 
    System.out.println("Tomorrow is " + tomorrow); 
} catch (Exception e) { 
    e.printStackTrace(); 
} 

或爲 「SA-25-MAY」：

try { 
    String str_date = "SA-25-MAY"; 

    // remove SA 
    str_date = str_date.replaceFirst("..-", ""); 

    // add current year 
    Calendar c = Calendar.getInstance(); 
    str_date = c.get(Calendar.YEAR) + "-" + str_date; 

    // parse date 
    Date date; 
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-dd-MMM"); 
    date = formatter.parse(str_date); 
    System.out.println("Today is " + date); 

    // add day 
    c.setTime(date); 
    c.add(Calendar.DATE, 1); 

    // rebuild the old pattern with the new date 
    SimpleDateFormat formatter2 = new SimpleDateFormat("EEE-dd-MMM"); 
    String tomorrow = formatter2.format(c.getTime()); 
    tomorrow = tomorrow.toUpperCase(); 
    tomorrow = tomorrow.substring(0, 2) + tomorrow.substring(3); 
    System.out.println("Tomorrow is " + tomorrow); 
} catch (Exception e) { 
    e.printStackTrace(); 
} 

Answer 2

ddd不能匹配SUN。如果您想在一週內匹配星期幾名稱，請改用EEE。