Question

以下代码的主要思想是比较两个日期，精度为1分钟。

rc是参考时间，tc是测试的时间：

// Checking precision of 1 minute
Calendar upperBound, lowerBound;
DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy hh:mm");

upperBound = (Calendar)rc.clone();
upperBound.add(Calendar.MINUTE, 1);
lowerBound = (Calendar)rc.clone();
lowerBound.add(Calendar.MINUTE, -1);

//Actual values
System.out.println("test "+dateFormat.format(tc.getTime()));
System.out.println("UpperB"+dateFormat.format(upperBound.getTime()));
System.out.println("LowerB "+dateFormat.format(lowerBound.getTime()));
//Tests
System.out.println("test after "+tc.after(lowerBound));
System.out.println("test before "+tc.before(upperBound));

输出如下：

test 05/10/2015 09:43.

UpperB 05/10/2015 09:44.

LowerB 05/10/2015 09:42.

test after false.

test before true.

我很困惑，因为测试日期与下限的Calendar.after()比较返回false，其中应该是true之前打印的日期。

任何想法，也许我做错了什么？

Answer 1

使用JDK 1.8进行测试：

        Calendar tc = Calendar.getInstance();
        Calendar rc = Calendar.getInstance();

        Calendar upperBound, lowerBound;
        DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy hh:mm");

        upperBound = (Calendar) rc.clone();
        upperBound.add(Calendar.MINUTE, 1);
        lowerBound = (Calendar) rc.clone();
        lowerBound.add(Calendar.MINUTE, -1);

        //Actual values
        System.out.println("test " + dateFormat.format(tc.getTime()));
        System.out.println("UpperB " + dateFormat.format(upperBound.getTime()));
        System.out.println("LowerB " + dateFormat.format(lowerBound.getTime()));
        //Tests
        System.out.println("test after " + tc.after(lowerBound));
        System.out.println("test before " + tc.before(upperBound));

输出：

test 08/11/2015 05:34
UpperB 08/11/2015 05:35
LowerB 08/11/2015 05:33
test after true
test before true

Calendar.before（）返回错误的值

1 个答案: