TimeTable函数不工作

Question

我正在写一段代码来生成时间表。这个函数编译得很好，但是结果与我所期望的不一样。

方法：

         public String generateTimeTable(){
    //2 arrays for all the months of the year and days of the week.
    String[] months = {"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};
    String[] days = {"Mon","Tue","Wed","Thur","Fri","Sat","Sun"};



    DateTime today = new DateTime();
    DateTime start = today.plusDays(1).withTime(8, 0, 0, 0); // this makes it start at 8am the next day
    String finalString = "On" + " " + days[start.getDayOfWeek()-1] + " "+ start.getDayOfMonth() + " " + months[start.getMonthOfYear() - 1] + "\n"; //This is the string for the first day.
    // It should return something like "On Mon 13 February
    ArrayList<Course> list = listOfCourses(); //get a sorted list of courses



    while (start.toLocalDate().isBefore(this.startOfExams)) { // loop for everyday up until the start of exams
        String sub1 = list.get(0).toString() + "...from " + new Interval(start, start.plusHours(3)).toString().substring(11, 16) + " to " + new Interval(start, start.plusHours(3)).toString().substring(41, 46) + "\n";
        finalString += sub1;
        finalString += "\n";




        String break1 = "break...from " + new Interval(start.plusHours(3), start.plusHours(4)).toString().substring(11, 16) + " to " + new Interval(start.plusHours(3), start.plusHours(4)).toString().substring(41, 46) + "\n";
        // String break1 = "break..." + new Interval(start.plusHours(3), start.plusHours(4)) + "\n";
        finalString += break1;
        finalString += "\n";


        String sub2 = list.get(1).toString() + "..." + new Interval(start.plusHours(4), start.plusHours(7)) + "\n";
        finalString += sub2;
        finalString += "\n";


        String break2 = "LunchBreak...You need to eat! " + new Interval(start.plusHours(7), start.plusHours(8)) + "\n";
        finalString += break2;
        finalString += "\n";



        String sub3 = list.get(2).toString() + "..." + new Interval(start.plusHours(8), start.plusHours(10)) + "\n";
        finalString += sub3;
        finalString += "\n";


        String break3 = "break..." + new Interval(start.plusHours(10), start.plusHours(11)) + "\n";
        finalString += break3;
        finalString += "\n";


        String sub4 = list.get(3).toString() + "..." + new Interval(start.plusHours(11), start.plusHours(13)) + "\n";
        finalString += sub4;
        finalString += "\n";


        String break4 = "break..." + new Interval(start.plusHours(13), start.plusHours(14)) + "\n";
        finalString += break4;
        finalString += "\n";


        String sub5 = list.get(4).toString() + "..." + new Interval(start.plusHours(14), start.plusHours(15)) + "\n";
        finalString += sub5;
        finalString += "\n";


        String sub6 = list.get(5).toString() + "..." + new Interval(start.plusHours(15), start.plusHours((int) 15.5)) + "\n";
        //finalString += sub6;
        //finalString += "\n";


        start = start.plusDays(1); // Move along to the next day.

        finalString += "\n";
        finalString += "On" + " " + days[start.getDayOfWeek()-1] + " "+ start.getDayOfMonth() + " " + months[start.getMonthOfYear() - 1] + "\n";


    }
    return finalString + "EXAMM DAYYY!";


}

然而，在获取这些数据之后，我尝试用示例信息对其进行测试：

                  public static void main(String[] args) {
    // TODO Auto-generated method stub
    LocalDate examStart = new LocalDate(2016, 3, 1);

    Course chem = new Course("Chemistry", 2, examStart);
    Course math = new Course("Mathematics", 5, examStart);
    Course phys = new Course("physics", 8, examStart);
    Course french = new Course("French", 5, examStart);
    Course Bio = new Course("Biology", 3, examStart);
    Course eng = new Course("English", 6, examStart);


    TimeTable tt = new TimeTable(2016, 3, 1);

    tt.addCourse(chem);
    tt.addCourse(math);
    tt.addCourse(phys);
    tt.addCourse(french);
    tt.addCourse(Bio);
    tt.addCourse(eng);

    //FIRST THINGS FIRST: complete testing of updating confidence.
    //tt.updateConfidence("French", 1);

    String finals = tt.generateTimeTable();

    System.out.print(finals);




}

但是，它没有打印出我的时间表，它只打印在星期五4月1日EXAMM DAYYY！

有人知道为什么会这样吗？

Answer 1

月份是从Java Date类中的0 (而不是1 )索引的。所以你在为4月1日，而不是3月1日制定时间表。这可能是你想要的，我不确定。

在任何情况下，您都要为4月1日构建一个时间表，然后将开始日期设置为4月1日加一天，即4月2日。这会导致while循环出现问题，它永远不会运行:开始日期是考试日期之后。

您需要修复的另一个问题是，您没有遍历生成的list。您正在使用固定的索引来检索元素，这些元素可能适用于当前的设置，但它非常脆弱:如果您更改了课程的数量，您必须记住更改while循环体。最好使用for循环来遍历列表并打印元素。不过，这个问题目前还没有真正解决，因为您的while循环根本没有被执行。

它将帮助您学习如何使用IDE中的调试工具:您可以逐行遍历代码，并查看执行了什么。

Answer 2

似乎您在3月31日运行该程序，因此程序中使用的日期变量计算如下: examStart =2016年3月1日，start =31(今天)+1天，即4月1日。

当循环条件被评估为false时，即start不是在examstart之前，因此只有那些字符串被打印出来，而这些字符串是在外部循环中计算的。