用Java写一个宿舍管理员对学生信息进行增删改查的系统

以下是一个基于Java的简单宿舍管理员系统示例，演示如何使用面向对象的思想实现对学生信息进行增删改查的功能。本系统使用MySQL数据库存储学生信息，需要使用JDBC连接数据库。

1. 创建学生类

public class Student {
    private String id; // 学号
    private String name; // 姓名
    private int age; // 年龄
    private String gender; // 性别
    private String dorm; // 宿舍号

    public Student() {}

    public Student(String id, String name, int age, String gender, String dorm) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.dorm = dorm;
    }

    // getter和setter方法省略

    public String toString() {
        return "学号：" + id + "，姓名：" + name + "，年龄：" + age + "，性别：" + gender + "，宿舍号：" + dorm;
    }
}

2. 创建学生DAO类，实现对学生信息的增删改查操作

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class StudentDAO {
    private String url = "jdbc:mysql://localhost:3306/dbname"; // 数据库连接地址
    private String username = "root"; // 数据库用户名
    private String password = "123456"; // 数据库密码

    // 添加学生信息
    public void addStudent(Student student) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection(url, username, password);

            // 插入学生信息
            String sql = "INSERT INTO student(id, name, age, gender, dorm) VALUES(?, ?, ?, ?, ?)";
            ps = conn.prepareStatement(sql);
            ps.setString(1, student.getId());
            ps.setString(2, student.getName());
            ps.setInt(3, student.getAge());
            ps.setString(4, student.getGender());
            ps.setString(5, student.getDorm());
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            try {
                if (ps != null) {
                    ps.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    // 删除学生信息
    public void deleteStudent(String id) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection(url, username, password);

            // 删除学生信息
            String sql = "DELETE FROM student WHERE id=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1, id);
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            try {
                if (ps != null) {
                    ps.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    // 修改学生信息
    public void updateStudent(Student student) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection(url, username, password);

            // 更新学生信息
            String sql = "UPDATE student SET name=?, age=?, gender=?, dorm=? WHERE id=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1, student.getName());
            ps.setInt(2, student.getAge());
            ps.setString(3, student.getGender());
            ps.setString(4, student.getDorm());
            ps.setString(5, student.getId());
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            try {
                if (ps != null) {
                    ps.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    // 查询学生信息
    public List<Student> findStudentById(String id) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        List<Student> students = new ArrayList<Student>();
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection(url, username, password);

            // 查询学生信息
            String sql = "SELECT * FROM student WHERE id=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1, id);
            rs = ps.executeQuery();
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getString("id"));
                student.setName(rs.getString("name"));
                student.setAge(rs.getInt("age"));
                student.setGender(rs.getString("gender"));
                student.setDorm(rs.getString("dorm"));
                students.add(student);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            try {
                if (rs != null) {
                    rs.close();
                }
                if (ps != null) {
                    ps.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return students;
    }

    // 查询所有学生信息
    public List<Student> findAllStudents() {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        List<Student> students = new ArrayList<Student>();
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection(url, username, password);

            // 查询学生信息
            String sql = "SELECT * FROM student";
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getString("id"));
                student.setName(rs.getString("name"));
                student.setAge(rs.getInt("age"));
                student.setGender(rs.getString("gender"));
                student.setDorm(rs.getString("dorm"));
                students.add(student);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            try {
                if (rs != null) {
                    rs.close();
                }
                if (ps != null) {
                    ps.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return students;
    }
}

3. 创建宿舍管理员界面，使用控制台进行交互

import java.util.List;
import java.util.Scanner;

public class DormManager {
    private StudentDAO studentDAO = new StudentDAO();

    public static void main(String[] args) {
        DormManager dormManager = new DormManager();
        dormManager.showMenu();
    }

    // 显示主菜单
    public void showMenu() {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("********** 欢迎使用宿舍管理员系统 **********");
            System.out.println("1. 添加学生信息");
            System.out.println("2. 删除学生信息");
            System.out.println("3. 修改学生信息");
            System.out.println("4. 查询学生信息");
            System.out.println("5. 退出系统");
            System.out.print("请选择操作（输入数字）：");
            String choice = scanner.nextLine();
            switch (choice) {
                case "1":
                    addStudent();
                    break;
                case "2":
                    deleteStudent();
                    break;
                case "3":
                    updateStudent();
                    break;
                case "4":
                    findStudent();
                    break;
                case "5":
                    System.out.println("谢谢使用，再见！");
                    System.exit(0);
                default:
                    System.out.println("输入有误，请重新输入！");
            }
        }
    }

    // 添加学生信息
    public void addStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生信息（学号 姓名 年龄 性别 宿舍号）：");
        String[] infos = scanner.nextLine().split(" ");
        Student student = new Student(infos[0], infos[1], Integer.parseInt(infos[2]), infos[3], infos[4]);
        studentDAO.addStudent(student);
        System.out.println("学生信息添加成功！");
    }

    // 删除学生信息
    public void deleteStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入要删除的学生学号：");
        String id = scanner.nextLine();
        List<Student> students = studentDAO.findStudentById(id);
        if (students.size() == 0) {
            System.out.println("没有找到该学生信息！");
        } else {
            studentDAO.deleteStudent(id);
            System.out.println("学生信息删除成功！");
        }
    }

    // 修改学生信息
    public void updateStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入要修改的学生学号：");
        String id = scanner.nextLine();
        List<Student> students = studentDAO.findStudentById(id);
        if (students.size() == 0) {
            System.out.println("没有找到该学生信息！");
        } else {
            System.out.println("请输入要修改的学生信息（姓名 年龄 性别 宿舍号）：");
            String[] infos = scanner.nextLine().split(" ");
            Student student = new Student(id, infos[0], Integer.parseInt(infos[1]), infos[2], infos[3]);
            studentDAO.updateStudent(student);
            System.out.println("学生信息修改成功！");
        }
    }

    // 查询学生信息
    public void findStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入要查询的学生学号（输入0查询所有）：");
        String id = scanner.nextLine();
        List<Student> students;
        if (id.equals("0")) {
            students = studentDAO.findAllStudents();
        } else {
            students = studentDAO.findStudentById(id);
        }
        if (students.size() == 0) {
            System.out.println("没有找到该学生信息！");
        } else {
            for (Student student : students) {
                System.out.println(student);
            }
        }
    }
}

运行宿舍管理员系统，即可进行学生信息的增删改查操作。