用Java写一个题目19：课外兴趣小组管理19【问题描述】1该系统主要处理课外兴趣小组的相关信息。2学生信息主要包括：学号、姓名、性别、兴趣爱好等内容。3兴趣主要包括：兴趣编号、兴趣类型等内容。4完成以下的操作：实现学生兴趣信息的添加、修改、删除和查询。【任务要求】1建立学生类、兴趣类、兴趣类型类2学生、兴趣、兴趣类型信息的初始化3学生、兴趣、兴趣类型信息的添加、修改、删除、查找4学生兴趣信息的输

下面是一个用Java实现的题目19的示例代码：

import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

class Student {
    private String id;
    private String name;
    private String gender;
    private String hobby;

    public Student(String id, String name, String gender, String hobby) {
        this.id = id;
        this.name = name;
        this.gender = gender;
        this.hobby = hobby;
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public String getGender() {
        return gender;
    }

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }
}

class Interest {
    private String id;
    private String type;

    public Interest(String id, String type) {
        this.id = id;
        this.type = type;
    }

    public String getId() {
        return id;
    }

    public String getType() {
        return type;
    }
}

class InterestType {
    private String id;
    private String name;

    public InterestType(String id, String name) {
        this.id = id;
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }
}

public class Main {
    private static List<Student> students = new ArrayList<>();
    private static List<Interest> interests = new ArrayList<>();
    private static List<InterestType> interestTypes = new ArrayList<>();

    public static void main(String[] args) {
        initializeData();

        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加学生兴趣信息");
            System.out.println("2. 修改学生兴趣信息");
            System.out.println("3. 删除学生兴趣信息");
            System.out.println("4. 查询学生兴趣信息");
            System.out.println("5. 输出学生兴趣信息");
            System.out.println("6. 保存学生兴趣信息为文件");
            System.out.println("0. 退出");

            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    addStudentInterest(scanner);
                    break;
                case 2:
                    modifyStudentInterest(scanner);
                    break;
                case 3:
                    deleteStudentInterest(scanner);
                    break;
                case 4:
                    queryStudentInterest(scanner);
                    break;
                case 5:
                    outputStudentInterest();
                    break;
                case 6:
                    saveStudentInterestToFile();
                    break;
                case 0:
                    System.exit(0);
                    break;
                default:
                    System.out.println("请输入正确的操作编号！");
            }
        }
    }

    private static void initializeData() {
        students.add(new Student("001", "张三", "男", "篮球"));
        students.add(new Student("002", "李四", "女", "音乐"));
        students.add(new Student("003", "王五", "男", "游戏"));

        interests.add(new Interest("001", "1"));
        interests.add(new Interest("002", "2"));
        interests.add(new Interest("003", "1"));

        interestTypes.add(new InterestType("1", "体育"));
        interestTypes.add(new InterestType("2", "音乐"));
    }

    private static void addStudentInterest(Scanner scanner) {
        System.out.println("请输入学生学号：");
        String id = scanner.next();

        System.out.println("请输入学生姓名：");
        String name = scanner.next();

        System.out.println("请输入学生性别：");
        String gender = scanner.next();

        System.out.println("请输入学生兴趣爱好：");
        String hobby = scanner.next();

        students.add(new Student(id, name, gender, hobby));
        System.out.println("学生兴趣信息添加成功！");
    }

    private static void modifyStudentInterest(Scanner scanner) {
        System.out.println("请输入要修改的学生学号：");
        String id = scanner.next();

        boolean found = false;
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入学生新的兴趣爱好：");
                String hobby = scanner.next();
                student.setHobby(hobby);
                found = true;
                System.out.println("学生兴趣信息修改成功！");
                break;
            }
        }

        if (!found) {
            System.out.println("找不到该学生的兴趣信息！");
        }
    }

    private static void deleteStudentInterest(Scanner scanner) {
        System.out.println("请输入要删除的学生学号：");
        String id = scanner.next();

        boolean found = false;
        for (int i = 0; i < students.size(); i++) {
            if (students.get(i).getId().equals(id)) {
                students.remove(i);
                found = true;
                System.out.println("学生兴趣信息删除成功！");
                break;
            }
        }

        if (!found) {
            System.out.println("找不到该学生的兴趣信息！");
        }
    }

    private static void queryStudentInterest(Scanner scanner) {
        System.out.println("请输入要查询的学生学号：");
        String id = scanner.next();

        boolean found = false;
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("学号：" + student.getId());
                System.out.println("姓名：" + student.getName());
                System.out.println("性别：" + student.getGender());
                System.out.println("兴趣爱好：" + student.getHobby());
                found = true;
                break;
            }
        }

        if (!found) {
            System.out.println("找不到该学生的兴趣信息！");
        }
    }

    private static void outputStudentInterest() {
        for (Student student : students) {
            System.out.println("学号：" + student.getId());
            System.out.println("姓名：" + student.getName());
            System.out.println("性别：" + student.getGender());
            System.out.println("兴趣爱好：" + student.getHobby());
            System.out.println();
        }
    }

    private static void saveStudentInterestToFile() {
        try {
            FileWriter writer = new FileWriter("student_interest.txt");
            for (Student student : students) {
                writer.write("学号：" + student.getId() + "\n");
                writer.write("姓名：" + student.getName() + "\n");
                writer.write("性别：" + student.getGender() + "\n");
                writer.write("兴趣爱好：" + student.getHobby() + "\n");
                writer.write("\n");
            }
            writer.close();
            System.out.println("学生兴趣信息保存成功！");
        } catch (IOException e) {
            System.out.println("保存学生兴趣信息失败：" + e.getMessage());
        }
    }
}

运行以上代码，可以根据提示选择操作，并进行学生兴趣信息的添加、修改、删除、查询、输出和保存等操作。学生兴趣信息会保存在一个文本文件中，文件名为student_interest.txt