简单的学生信息管理系统
import java.sql.*;
import java.util.Scanner;
public class StudentManagementSystem {
private static final String URL = "jdbc:mysql://localhost:3306/test";
private static final String USER = "root";
private static final String PASSWORD = "root";
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String input;
System.out.println("\n欢迎使用学生管理系统，请登录：");
while (!login(scanner)) {
}
do {
System.out.println("\n学生管理系统");
System.out.println("1. 增加学生");
System.out.println("2. 删除学生");
System.out.println("3. 修改学生信息");
System.out.println("4. 查询学生信息");
System.out.println("5. 浏览所有学生");
System.out.println("0. 退出");
System.out.print("请选择操作: ");
input = scanner.nextLine();
switch (input) {
case "1":
addStudent(scanner);
break;
case "2":
deleteStudent(scanner);
break;
case "3":
updateStudent(scanner);
break;
case "4":
searchStudent(scanner);
break;
case "5":
listStudents(scanner);
break;
case "0":
System.out.println("退出系统");
break;
default:
System.out.println("无效的输入，请重新选择。");
}
} while (!input.equals("0"));
scanner.close();
}
private static boolean login(Scanner scanner) {
System.out.print("请输入用户名: ");
String username = scanner.nextLine();
System.out.print("请输入密码: ");
String password = scanner.nextLine();
if ("root".equals(username) && "root".equals(password)) {
System.out.println("登录成功！");
return true;
} else {
System.out.println("用户名或密码错误！");
return false;
}
}
private static void addStudent(Scanner scanner) {
Connection conn = connectDatabase();
if (conn != null) {
try {
System.out.print("输入学生姓名: ");
String name = scanner.nextLine();
System.out.print("输入学生年龄: ");
int age = Integer.parseInt(scanner.nextLine());
System.out.print("输入学生年级: ");
String grade = scanner.nextLine();
String sql = "INSERT INTO students (name, age, grade) VALUES (?, ?, ?)";
try (PreparedStatement stmt = conn.prepareStatement(sql)) {
stmt.setString(1, name);
stmt.setInt(2, age);
stmt.setString(3, grade);
int rowsAffected = stmt.executeUpdate();
if (rowsAffected > 0) {
System.out.println("学生信息添加成功！");
} else {
System.out.println("添加失败！");
}
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConnection(conn);
}
}
}
private static void deleteStudent(Scanner scanner) {
Connection conn = connectDatabase();
if (conn != null) {
try {
System.out.print("输入要删除的学生ID: ");
int id = Integer.parseInt(scanner.nextLine());
String sql = "DELETE FROM students WHERE id = ?";
try (PreparedStatement stmt = conn.prepareStatement(sql)) {
stmt.setInt(1, id);
int rowsAffected = stmt.executeUpdate();
if (rowsAffected > 0) {
System.out.println("学生信息删除成功！");
} else {
System.out.println("删除失败，可能该学生ID不存在！");
}
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConnection(conn);
}
}
}
private static void updateStudent(Scanner scanner) {
Connection conn = connectDatabase();
if (conn != null) {
try {
System.out.print("输入要修改的学生ID: ");
int id = Integer.parseInt(scanner.nextLine());
System.out.print("输入新的姓名: ");
String name = scanner.nextLine();
System.out.print("输入新的年龄: ");
int age = Integer.parseInt(scanner.nextLine());
System.out.print("输入新的年级: ");
String grade = scanner.nextLine();
String sql = "UPDATE students SET name = ?, age = ?, grade = ? WHERE id = ?";
try (PreparedStatement stmt = conn.prepareStatement(sql)) {
stmt.setString(1, name);
stmt.setInt(2, age);
stmt.setString(3, grade);
stmt.setInt(4, id);
int rowsAffected = stmt.executeUpdate();
if (rowsAffected > 0) {
System.out.println("学生信息更新成功！");
} else {
System.out.println("更新失败，可能该学生ID不存在！");
}
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConnection(conn);
}
}
}
private static void searchStudent(Scanner scanner) {
Connection conn = connectDatabase();
if (conn != null) {
try {
System.out.print("输入要查询的学生ID: ");
int id = Integer.parseInt(scanner.nextLine());
String sql = "SELECT * FROM students WHERE id = ?";
try (PreparedStatement stmt = conn.prepareStatement(sql)) {
stmt.setInt(1, id);
ResultSet rs = stmt.executeQuery();
if (rs.next()) {
int studentId = rs.getInt("id");
String studentName = rs.getString("name");
int studentAge = rs.getInt("age");
String studentGrade = rs.getString("grade");
System.out.println("学生ID: " + studentId);
System.out.println("姓名: " + studentName);
System.out.println("年龄: " + studentAge);
System.out.println("年级: " + studentGrade);
} else {
System.out.println("未找到该学生信息！");
}
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConnection(conn);
}
}
}
private static void listStudents(Scanner scanner) {
Connection conn = connectDatabase();
if (conn != null) {
try {
String sql = "SELECT * FROM students";
try (Statement stmt = conn.createStatement()) {
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
int studentId = rs.getInt("id");
String studentName = rs.getString("name");
int studentAge = rs.getInt("age");
String studentGrade = rs.getString("grade");
System.out.println("学生ID: " + studentId + ", 姓名: " + studentName + ", 年龄: " + studentAge + ", 年级: " + studentGrade);
}
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConnection(conn);
}
}
}
private static Connection connectDatabase() {
try {
return DriverManager.getConnection(URL, USER, PASSWORD);
} catch (SQLException e) {
e.printStackTrace();
return null;
}
}
private static void closeConnection(Connection connection) {
try {
if (connection != null && !connection.isClosed()) {
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
