为什么Java中的Calendar在Java和Android下结果不一样

[yufz]

在java 环境下打运行
Calendar c=Calendar.getInstance();
c.setFirstDayOfWeek(Calendar.MONDAY);
System.out.println(c);
System.out.println(c.get(Calendar.WEEK_OF_YEAR));

打印结果，周数48是对的
java.util.GregorianCalendar[time=1385876708339,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Shanghai",offset=28800000,dstSavings=0,useDaylight=false,transitions=19,lastRule=null],firstDayOfWeek=2,minimalDaysInFirstWeek=1,ERA=1,YEAR=2013,MONTH=11,WEEK_OF_YEAR=48,WEEK_OF_MONTH=1,DAY_OF_MONTH=1,DAY_OF_YEAR=335,DAY_OF_WEEK=1,DAY_OF_WEEK_IN_MONTH=1,AM_PM=1,HOUR=1,HOUR_OF_DAY=13,MINUTE=45,SECOND=8,MILLISECOND=339,ZONE_OFFSET=28800000,DST_OFFSET=0]
48

但是同样的代码在android环境下就成了这样 周数变成了49
java.util.GregorianCalendar[time=1385876864988,areFieldsSet=true,lenient=true,zone=Asia/Shanghai,firstDayOfWeek=2,minimalDaysInFirstWeek=1,ERA=1,YEAR=2013,MONTH=11,WEEK_OF_YEAR=49,WEEK_OF_MONTH=1,DAY_OF_MONTH=1,DAY_OF_YEAR=335,DAY_OF_WEEK=1,DAY_OF_WEEK_IN_MONTH=1,AM_PM=1,HOUR=1,HOUR_OF_DAY=13,MINUTE=47,SECOND=44,MILLISECOND=988,ZONE_OFFSET=28800000,DST_OFFSET=0]
49

不知道是什么原因，求解释

[xell]

http://stackoverflow.com/questions/12481505/different-behavior-of-calendar-class-in-java-and-android

顺便一篇不太相关但我一直收藏着的：

http://stackoverflow.com/questions/344380/why-is-january-month-0-in-java-calendar

[yufz]

@xell 这个情况我也碰到过，set之后需要get一次日期时间什么的才会更新

但是这次的情况不知何原因了

等有时间得自习看看源码了