用java实现一个简易的学生选课系统

好的，我可以给你提供一个简单的学生选课系统的JAVA实现代码：

import java.util.ArrayList;
import java.util.Scanner;

public class CourseSelectionSystem {
    public static void main(String[] args) {
        // 定义学生列表和课程列表
        ArrayList<Student> studentList = new ArrayList<>();
        ArrayList<Course> courseList = new ArrayList<>();

        // 初始化课程列表
        courseList.add(new Course("Java程序设计", "张三", "周一 1-2节", "教1-101", 3));
        courseList.add(new Course("计算机网络", "李四", "周二 3-4节", "教1-102", 2));
        courseList.add(new Course("数据结构与算法", "王五", "周三 5-6节", "教1-103", 4));

        // 实现一个菜单，提供学生选择课程和查询已选课程的功能
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 学生选课");
            System.out.println("2. 查询已选课程");
            System.out.println("3. 退出系统");
            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    System.out.println("请输入学生姓名：");
                    String name = scanner.next();
                    System.out.println("请输入学号：");
                    int id = scanner.nextInt();
                    System.out.println("请选择课程编号：");
                    for (int i = 0; i < courseList.size(); i++) {
                        System.out.println((i + 1) + ". " + courseList.get(i).toString());
                    }
                    int courseIndex = scanner.nextInt() - 1;
                    Course selectedCourse = courseList.get(courseIndex);
                    if (selectedCourse.getNumberOfStudents() < selectedCourse.getCapacity()) {
                        Student student = new Student(name, id, selectedCourse);
                        studentList.add(student);
                        selectedCourse.addStudent();
                        System.out.println("选课成功！");
                    } else {
                        System.out.println("该课程已满员，选课失败！");
                    }
                    break;
                case 2:
                    System.out.println("请输入学号：");
                    int searchId = scanner.nextInt();
                    for (Student student : studentList) {
                        if (student.getId() == searchId) {
                            System.out.println("已选课程：");
                            System.out.println(student.getSelectedCourse().toString());
                            break;
                        }
                    }
                    break;
                case 3:
                    System.out.println("感谢使用本系统！");
                    return;
                default:
                    System.out.println("输入有误，请重新选择！");
                    break;
            }
        }
    }
}

class Course {
    private String name;
    private String teacher;
    private String time;
    private String location;
    private int capacity;
    private int numberOfStudents;

    public Course(String name, String teacher, String time, String location, int capacity) {
        this.name = name;
        this.teacher = teacher;
        this.time = time;
        this.location = location;
        this.capacity = capacity;
        this.numberOfStudents = 0;
    }

    public String getName() {
        return name;
    }

    public String getTeacher() {
        return teacher;
    }

    public String getTime() {
        return time;
    }

    public String getLocation() {
        return location;
    }

    public int getCapacity() {
        return capacity;
    }

    public int getNumberOfStudents() {
        return numberOfStudents;
    }

    public void addStudent() {
        numberOfStudents++;
    }

    public String toString() {
        return name + " (" + teacher + ") " + time + " " + location + " " + numberOfStudents + "/" + capacity;
    }
}

class Student {
    private String name;
    private int id;
    private Course selectedCourse;

    public Student(String name, int id, Course selectedCourse) {
        this.name = name;
        this.id = id;
        this.selectedCourse = selectedCourse;
    }

    public String getName() {
        return name;
    }

    public int getId() {
        return id;
    }

    public Course getSelectedCourse() {
        return selectedCourse;
    }
}

这个代码实现了一个简单的学生选课系统，包括学生类、课程类和主函数。在主函数中，我们通过一个菜单提供学生选择课程和查询已选课程的功能。在学生选择课程时，我们会检查该课程是否已满员，如果已满员则不能选择该课程。在查询已选课程时，我们会遍历学生列表，找到该学生所选的所有课程并输出。