我正在编写一个需要处理日期的程序。我收到一个输入日期,它是一周的开始日期(星期一)。在这种情况下,时间为CET 2015年1月5日星期一。
然后,我需要定义一周中其他日期的日期。
我试图这样做:
Calendar cStart = Calendar.getInstance();
Calendar cMon = Calendar.getInstance();
Calendar cTue = Calendar.getInstance();
Calendar cWed = Calendar.getInstance();
Calendar cThu = Calendar.getInstance();
Calendar cFri = Calendar.getInstance();
Calendar cSat = Calendar.getInstance();
Calendar cSun = Calendar.getInstance();
cMon = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cTue = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cWed = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cThu = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cFri = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cSat = cStart;
cStart.add(Calendar.DAY_OF_MONTH, 1);
cSun = cStart;
System.out.println(cMon.getTime());
System.out.println(cTue.getTime());
System.out.println(cWed.getTime());
System.out.println(cThu.getTime());
System.out.println(cFri.getTime());
System.out.println(cSat.getTime());
System.out.println(cSun.getTime());
现在我的问题是,输出应如下所示:
Mon Jan 05 00:00:00 CET 2015
Tue Jan 06 00:00:00 CET 2015
Wed Jan 07 00:00:00 CET 2015
Thu Jan 08 00:00:00 CET 2015
Fri Jan 09 00:00:00 CET 2015
Sat Jan 10 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
但实际上看起来像这样:
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
Sun Jan 11 00:00:00 CET 2015
我该怎么办才能收到所需的输出?
最佳答案
您正在为每个变量分配cStart
的引用。使用clone()
方法,每次都可以获取一个新对象。
Calendar cStart = Calendar.getInstance();
Calendar cMon = null;
Calendar cTue = null;
Calendar cWed = null;
Calendar cThu = null;
Calendar cFri = null;
Calendar cSat = null;
Calendar cSun = null;
cMon = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cTue = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cWed = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cThu = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cFri = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cSat = (Calendar) cStart.clone();
cStart.add(Calendar.DAY_OF_MONTH, 1);
cSun = (Calendar) cStart.clone();
System.out.println(cMon.getTime());
System.out.println(cTue.getTime());
System.out.println(cWed.getTime());
System.out.println(cThu.getTime());
System.out.println(cFri.getTime());
System.out.println(cSat.getTime());
System.out.println(cSun.getTime());
输出量
Mon Feb 22 12:45:39 CET 2016
Tue Feb 23 12:45:39 CET 2016
Wed Feb 24 12:45:39 CET 2016
Thu Feb 25 12:45:39 CET 2016
Fri Feb 26 12:45:39 CET 2016
Sat Feb 27 12:45:39 CET 2016
Sun Feb 28 12:45:39 CET 2016