java - 访问存储在 ArrayList 中的对象的最佳方式？

Question

我有一个 Student 类，其中包含 Course 类型的 ArrayList，并且 Course 是包含一些内容的类像 className、classTime 等字段以及适当的 getter 和 setter。假设我创建了一个 Course 的 ArrayList 并将其存储到 Student 类中。

例如，我如何打印特定Course对象的className(该对象存储在存储在中的ArrayList中)学生类)？

到目前为止，我尝试过这个，下面是类 Student 的部分代码:

class Student {
    ArrayList<Course> studentSchedule;

    public ArrayList<Course> getStudentSchedule() {
        return studentSchedule;
    }

    public void setStudentSchedule(ArrayList<Course> studentSchedule) {
        this.studentSchedule = studentSchedule;
    }
}

然后我有一些代码创建了 Student 类型的 student1 并将 Course 的 ArrayList 存储到其中.

假设我想访问 student1 中 ArrayList 的第一个对象中的 className。到目前为止我已经有了这个并且它可以工作......可以吗？

ArrayList<Course> schedule = student1.getStudentSchedule();

System.out.print("\n course name at position 0 is " +
    student1.getStudentScheduleClassName(0));

为此目的创建另一个 Arraylist 感觉很奇怪......但后来我想，从第 1 行开始，schedule 将只包含指向位置并且不应该占用太多空间？

有更合适的方法吗？

Answer 1

根据上述讨论我尝试完成解决方案供我引用。

导入java.util.ArrayList;

导入java.util.Iterator;

公共(public)类ListExample {

public static void main(String[] args) {

    Student student1 = new Student();

    ArrayList<Course> student1Schedule = new ArrayList<Course>();
    student1Schedule.add(new Course("Computer Science", "Training Room"));
    student1Schedule.add(new Course("Mobile App Development", "Training Room 2"));

    student1.setStudentSchedule(student1Schedule);
    // Prints only one course 
    System.out.println(" ** Course" + student1.getStudentSchedule().get(0).toString());
    // Print all the courses attended by the student
    ArrayList<Course> studentDetails = student1.getStudentSchedule();
    Iterator<Course> studentIterator = studentDetails.iterator();
    while (studentIterator.hasNext()) {
        Course courseName = studentIterator.next();
        System.out.println(courseName);
    }

}


static class Student {

    private ArrayList<Course> studentSchedule;

    public ArrayList<Course> getStudentSchedule() {
        return studentSchedule;
    }

    public void setStudentSchedule(ArrayList<Course> studentSchedule) {
        this.studentSchedule = studentSchedule;
    } 
}

static class Course {

    private String courseName;
    private String className;

    public Course (String courseName, String className){
        this.className =className;
        this.courseName = courseName;
    }
    public String getCourseName() {
        return courseName;
    }
    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }
    public String getClassName() {
        return className;
    }
    public void setClassName(String className) {
        this.className = className;
    }

    public String toString (){
        return "Course Name :" + this.courseName + "\n" + "Class Name : " + className + "\n";

    }

}

}