Question

我正在制作一本成绩簿，用于存储学生和教师，每个学生和教师都有一个唯一的ID，以及他们在学生和教师对象中注册或教授ArrayList的各自课程。我有文件夹路径＆＃34; J：/ compsci / Classes /＆＃34;存储每个类的文本文件。

文本文件格式：

第1行：班级名称，教师ID，期间，荣誉？，班级ID

第2行：以逗号分隔的班级中每个学生的学生ID。

我在这里初始化每个学生正在学习的所有课程，每个老师正在教授的所有课程，以及每个班级的所有学生和信息。

基于我迄今为止所学到的一切，我在本地范围内重新定义了类对象c for-loop因此它应该是一个全新的对象，最初没有学生，但在下面的行中，它包括来自所有以前类的学生在打印时进行调试。

请帮助我花了一周的时间来解决这个问题

调试代码

File[] classes = new File("J:/compsci/Classes/").listFiles();
for (File currentClass: classes) {
    System.out.println(currentClass.getPath());//proves that i'm moving to a different class
    try (Scanner fileReader = new Scanner (new FileInputStream (currentClass.getPath()))){
        String[] classInfo= fileReader.nextLine().split(",");
        for (String s: classInfo)//all the info going into the parameters for a new class
            System.out.print(s+",");
        System.out.println();
        Class c = new Class (classInfo[0],classInfo[1],Integer.parseInt(classInfo[2]),classInfo[3].equals("H"),currentClassID());
        for (Student s: c.getStudents())//PROBLEM!! should always be empty initially and not store students from previous classes!!
            System.out.print(s.getID()+",");
        System.out.println();
        String[] studentslist= fileReader.nextLine().split(",");
        for (String s: studentslist)
            c.addStudent((Student)getUserFromID(s));
        ((Teacher)getUserFromID(classInfo[1])).addClass(c);
        for (String s: studentslist) {//prints the only students that are actually supposed to be in the class
            System.out.println(s);
            ((Student)getUserFromID(s)).addClass(c);
        }
        CLASSLIST.add(c);//global arraylist storing all classes
    } catch (Exception e) {
        e.printStackTrace();
    }
}

控制台输出

J:\compsci\Classes\APBiology.txt
AP Biology,00009,5,H,00001,

00001
00003
00004
00011
J:\compsci\Classes\Chinese5AP.txt
Chinese 5 AP,00007,0,H,00002,
00001,00003,00004,00011,
00005
00011
J:\compsci\Classes\ComputerScienceA.txt
Computer Science A,00007,2,H,00003,
00001,00003,00004,00011,00005,00011,
00001
00002
00003
00004
00005
J:\compsci\Classes\ComputerSciencePrinciples.txt
Computer Science Principles,00007,3,H,00004,
00001,00003,00004,00011,00005,00011,00001,00002,00003,00004,00005,
00003
00004
00005
00011
00001

没有任何调试的代码

File[] classes = new File("J:/compsci/Classes/").listFiles();
for (File currentClass: classes) {
    try (Scanner fileReader = new Scanner (new FileInputStream (currentClass.getPath()))){
        String[] classInfo= fileReader.nextLine().split(",");
        String[] studentslist= fileReader.nextLine().split(",");
        Class c = new Class (classInfo[0],classInfo[1],Integer.parseInt(classInfo[2]),classInfo[3].equals("H"),currentClassID());
        ((Teacher)getUserFromID(classInfo[1])).addClass(c);
        for (String s: studentslist)
            c.addStudent((Student)getUserFromID(s));
        for (String s: studentslist)
            ((Student)getUserFromID(s)).addClass(c);
        CLASSLIST.add(c);//global arraylist storing all classes
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Answer 1

由于您在创建新的C类后发生了问题：

Class c = new Class (classInfo[0],classInfo[1],Integer.parseInt(classInfo[2]),classInfo[3].equals("H"),currentClassID());
for (Student s: c.getStudents())//PROBLEM!! should always be empty initially and not store students from previous classes!!

但是你没有附上你的Class构造函数，我猜你错过了重置List的学生attriburte。请添加

students = new ArrayList<>();

到Class构造函数。

Answer 2

是的，所以显然我把我的类对象中的arraylist作为静态oops。没有意识到搞砸了一切

为什么Aren的变量重置每个循环？

2 个答案: