的Java simpledateformat.format是給不正確的日期爲上週年

Question

這實際上是y的重複返回2012而在Y回報2011年的SimpleDateFormat我要重複的丁俊暉在這一個不是一個下面列出。我讀到了答案，我仍然認爲那裏有錯誤。我的系統中的第一天是星期天，所以通過java.doc的描述，這應該是2017年的第53周而不是2018年的第1周，如果我將在1月1日到6日出現錯誤，應該是已經回到2017年

這不是日曆返回不正確的日期的副本，日曆工作正常。請參閱下面的其他信息我試圖簡化我的代碼在EOD的顯示目的，因爲我希望走出門外

當使用SimpleDateFormat.Format轉換日曆日期爲12/31/2017（2017， ,31,0,0）（星期日的第一天，這一年的最後一週）SimpleDateFormat返回12/31/。我已經用java 6,7,8試過了，並且得到了相同的結果，我在兩個不同版本的eclipse上試過了，我在另一個開發人員的計算機上嘗試過，所有這些結果都是一樣的。這是從我的實際junit代碼中提取的。

import java.text.SimpleDateFormat; 
import java.util.ArrayList; 
import java.util.Calendar; 
import java.util.Date; 

public class SimpleDateTest2 { 

public static void main(String[] args) { 
    // TODO Auto-generated method stub 

    Calendar t_calendar = Calendar.getInstance(); 
    Calendar m_calc_calendar = Calendar.getInstance(); 
    int rc=0; 
    int testDays=20; 
    Date rDate; 
    SimpleDateFormat ssaDateFormat= new SimpleDateFormat("YYMMdd"); 
    SimpleDateFormat logDateFormat= new SimpleDateFormat("E MM/dd/YYYY"); 
    ArrayList<Date> testDates = new ArrayList<Date>(); 
    t_calendar.set(2017,11,20,0,0); // start date 
    //t_calendar.set(2018,11,20,0,0); // start date 
    t_calendar.setLenient(false); 
    // builds 2600 dates for test run reason for Date (24 bytes) vs Calendar (423 bytes) 
    for(int days=0; days<testDays;days++){ 
     t_calendar.add(Calendar.DATE, 1); 
     testDates.add(t_calendar.getTime()); 
    } 

    for(Date testDate: testDates){ 
    String test = testDate.toString(); 
     System.out.println("toString: " + test); 
     t_calendar.setTimeInMillis(testDate.getTime()); 
     test = ssaDateFormat.format(t_calendar.getTime()); 
     System.out.println(" Cal.year " + t_calendar.get(Calendar.YEAR) + " Cal.month " + t_calendar.get(Calendar.MONTH) + " Cal.day " + t_calendar.get(Calendar.DATE) + " Cal.week " + t_calendar.get(Calendar.WEEK_OF_YEAR)); 
     System.out.println("ssa conversion: " + test); 
     test = logDateFormat.format(t_calendar.getTime()); 
     System.out.println("log conversion: " + test); 
     System.out.println(t_calendar.toString()); 
     System.out.println(""); 
     // call to method under test 
     //rDate=rsl.calculateSSATransDate(ssaDateFormat.format(testDate),new BigDecimal(1.0)); 
     // result validation. 

    } 

} 

測試結果

toString: Sat Dec 29 00:00:53 PST 2018 <-- input date 
Cal.year 2018 Cal.month 11 Cal.day 29 Cal.week 52 
ssa conversion: 181229 
log conversion: Sat 12/29/2018 <-- result is good 
java.util.GregorianCalendar[time=1546070453716,areFieldsSet=true,areAllFieldsSet=true,lenient=false,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2018,MONTH=11,WEEK_OF_YEAR=52,WEEK_OF_MONTH=5,DAY_OF_MONTH=29,DAY_OF_YEAR=363,DAY_OF_WEEK=7,DAY_OF_WEEK_IN_MONTH=5,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=53,MILLISECOND=716,ZONE_OFFSET=-28800000,DST_OFFSET=0] 

toString: Sun Dec 30 00:00:53 PST 2018 <-- Input date 
Cal.year 2018 Cal.month 11 Cal.day 30 Cal.week 1 
ssa conversion: 191230 <-- Result is bad 
log conversion: Sun 12/30/2019 
java.util.GregorianCalendar[time=1546156853716,areFieldsSet=true,areAllFieldsSet=true,lenient=false,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2018,MONTH=11,WEEK_OF_YEAR=1,WEEK_OF_MONTH=6,DAY_OF_MONTH=30,DAY_OF_YEAR=364,DAY_OF_WEEK=1,DAY_OF_WEEK_IN_MONTH=5,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=53,MILLISECOND=716,ZONE_OFFSET=-28800000,DST_OFFSET=0] 

toString: Mon Dec 31 00:00:53 PST 2018 <-- Input date 
Cal.year 2018 Cal.month 11 Cal.day 31 Cal.week 1 
ssa conversion: 191231 
log conversion: Mon 12/31/2019 <-- Result is bad 
java.util.GregorianCalendar[time=1546243253716,areFieldsSet=true,areAllFieldsSet=true,lenient=false,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2018,MONTH=11,WEEK_OF_YEAR=1,WEEK_OF_MONTH=6,DAY_OF_MONTH=31,DAY_OF_YEAR=365,DAY_OF_WEEK=2,DAY_OF_WEEK_IN_MONTH=5,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=53,MILLISECOND=716,ZONE_OFFSET=-28800000,DST_OFFSET=0] 

toString: Tue Jan 01 00:00:53 PST 2019 <-- input date 
Cal.year 2019 Cal.month 0 Cal.day 1 Cal.week 1 
ssa conversion: 190101 
log conversion: Tue 01/01/2019 <-- Result is good 
    java.util.GregorianCalendar[time=1546329653716,areFieldsSet=true,areAllFieldsSet=true,lenient=false,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2019,MONTH=0,WEEK_OF_YEAR=1,WEEK_OF_MONTH=1,DAY_OF_MONTH=1,DAY_OF_YEAR=1,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=53,MILLISECOND=716,ZONE_OFFSET=-28800000,DST_OFFSET=0] 

正如我期待我看這個問題重複這一模式

- in 2018 12/30 (Sun) and 12/31(Mon) in 2018, 
- in 2019 I have issues with 12/29(Sun), 12/30(Mon) and 12/31 (Tues) 
- in 2020 12/27(Sun), 12/28(Mon), 12/29(Tues), 12/30 (Wed) 12/31(Thurs) 
- in 2021 12/26(Sun) - 12/31(Fri) 
- 2022 is correct 
- 2023 restarts the loop. 

它與一年中的最後不完整的星期做的日期但我一直無法解決這個問題。

Answer 1

月份是0依據即一月份爲0十二月11

嘗試

c.set(2017, 11, 31, 0, 0);