大一下java期末设计：学生信息管理系统（荣获班上第一）

何平安2024-02-032024-08-03

其实就是当时我们没教数据库然后我会JDBC然后就得了第一了，一堆if判断语句，连个图形化界面都没有，现在看来还是感觉太低级了…–by 2024-2-7

从此之后就一直是期末设计第一了 –by 2024-8-2

先上java代码：

先上java代码：
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import java.util.Scanner;
import javax.swing.*;


public class cs2 extends JFrame {
public static void main(String[] args) {
// 未完成的swing界面设计
// JFrame frame = new JFrame("学生信息管理系统");
// frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// frame.setSize(600,400);
// frame.setVisible(true);
// frame.setLayout(new FlowLayout());
// JButton loginbutton=new JButton("登录");
// frame.add(loginbutton);
// JButton zhucebutton=new JButton("注册");
// frame.add(zhucebutton);
// JButton checkBot= new JButton("查询");
// checkBot.setEnabled(false);
// JButton luruBot =new JButton("录入");
// luruBot.setEnabled(false);
// frame.add(checkBot);
// frame.add(luruBot);
// ImageIcon imageIcon =new ImageIcon(("src/hehao.jpg"));
//
// JPanel loginPanel =new JPanel();
// loginPanel.setLayout(new GridLayout(3,2));
// loginPanel.add(new JLabel("姓名："));
// JTextField usernameField=new JTextField();
// loginPanel.add(new JLabel("密码:"));
// JTextField PasswordField= new JTextField();
// loginPanel.add(PasswordField);
// loginPanel.add(loginbutton);
// loginPanel.add(zhucebutton);
//
// loginbutton.addActionListener(new ActionListener() {
// @Override
// public void actionPerformed(ActionEvent e) {
// String username = usernameField.getText();
// String password = String.valueOf(PasswordField.getText());
// if(username.equals("name")&&password.equals("password")){
// loginbutton.setVisible(false);
// luruBot.setEnabled(true);
// checkBot.setEnabled(true);
// }else{
// JOptionPane.showMessageDialog(frame,
// "用户名或密码输入错误",
// "登录失败",
// JOptionPane.ERROR_MESSAGE);
// }
// }
// });
// zhucebutton.addActionListener(new ActionListener() {
// @Override
// public void actionPerformed(ActionEvent e) {
// loginbutton.setEnabled(false);
// }
// });
// SwingUtilities.invokeLater(new Runnable() {
// @Override
// public void run() {
// new cs2();
// }
// });2


System.out.println("欢迎使用学生信息管理系统！");
System.out.println("正在为你加载程序...");
final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
final String DB_URL = "jdbc:mysql://localhost:3306/hh";//数据库名为hh
final String USER = "root";
final String PASS = "123cd233";//账号和密码
System.out.println("请选择你的操作：登录按1，注册账号按2");
Scanner input = new Scanner(System.in);
int x = input.nextInt();
int y = 0;

Connection conn = null;
ResultSet rs = null;
PreparedStatement pstmt = null;
Statement stmt = null;
if (x != 1 && x != 2) {
System.out.println("您输入的有误，请重新运行程序");
System.exit(0);
}
zhuce:
while (x == 2) {
System.out.println("您已进入注册系统");
try {
Class.forName(JDBC_DRIVER);
conn = DriverManager.getConnection(DB_URL, USER, PASS);

Scanner scanner = new Scanner(System.in);
System.out.println("请输入你的学号:");
int id = scanner.nextInt();
System.out.println("请输入你的姓名:");
String name = scanner.next();
System.out.println("请输入你的注册的密码:");
String password = scanner.next();
String sql2 ="SELECT * FROM student WHERE id=? ";
pstmt=conn.prepareStatement(sql2);
pstmt.setInt(1,id);

String sql = "INSERT INTO student (id, name, password) VALUES (?, ?, ?)";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
pstmt.setString(2, name);
pstmt.setString(3, password);

int rows = pstmt.executeUpdate();
if (rows > 0) {
System.out.println("注册成功！");
}
} catch (Exception se) {
se.printStackTrace();
} finally {
try {
if (pstmt != null) pstmt.close();
if (conn != null) conn.close();
} catch (Exception se) {
se.printStackTrace();
}
}
x = -1;
}
denglu:
while (x == 1) {
System.out.println("您已进入登录系统");
try {
Class.forName(JDBC_DRIVER);
conn = DriverManager.getConnection(DB_URL, USER, PASS);

Scanner scanner = new Scanner(System.in);
System.out.println("请输入你的学号:");
int id = scanner.nextInt();
System.out.println("请输入你姓名:");
String name = scanner.next();
System.out.println("请输入你的密码:");
String password = scanner.next();

String sql = "SELECT * FROM student WHERE id = ? and name = ? and password = ?";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
pstmt.setString(2, name);
pstmt.setString(3, password);

rs = pstmt.executeQuery();
if (rs.next()) {
System.out.println("输入成功.");
y = 1;
} else {
System.out.println("你输入的有误，已为你重新运行登录系统请再次输入.");
y = 2;
}
} catch (Exception se) {
se.printStackTrace();
} finally {
try {
if (rs != null) rs.close();
if (pstmt != null) pstmt.close();
if (conn != null) conn.close();
} catch (Exception se) {
se.printStackTrace();
}
if (y == 1) {
break;
} else if (y == 2) {
continue;
}
}
}
if (y == 1) {
System.out.println("--------------------");
System.out.println("欢迎进入学生信息管理系统");
System.out.println("---------------------");
System.out.println("请选择你的操作：查询成绩请按1，录入成绩请按2");
int r = input.nextInt();
if (r == 2) {
System.out.println("请输入你的成绩：");
try {
Class.forName(JDBC_DRIVER);
conn = DriverManager.getConnection(DB_URL, USER, PASS);
Scanner scanner = new Scanner(System.in);
int score = scanner.nextInt();
System.out.println("请输入你的学号：");
int id = scanner.nextInt();
String sql = "UPDATE student SET score= ? WHERE id=?";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, score);
pstmt.setInt(2, id);

int rows = pstmt.executeUpdate();
if (rows > 0) {
System.out.println("录入成功！");
}
} catch (Exception se) {
se.printStackTrace();
} finally {
try {
if (pstmt != null) pstmt.close();
if (conn != null) conn.close();
} catch (Exception se) {
se.printStackTrace();
}
}
}
if (r == 1) {
System.out.println("请输入你的学号:");
try {
Class.forName(JDBC_DRIVER);
conn = DriverManager.getConnection(DB_URL,USER,PASS);
int id = input.nextInt();
String sql = "SELECT score FROM student WHERE id = ?"; // Use placeholders
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
rs = pstmt.executeQuery();
if(rs.next()) {
int score = rs.getInt("score");
System.out.println("成绩为: " + score+" , tips:如果未录入成绩默认成绩为0分");
}
input.close();
} catch (SQLException se) {
se.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (rs != null)
rs.close();
} catch (SQLException se) {
}
try {
if (pstmt != null)
pstmt.close();
} catch (SQLException se) {
}
try {
if (conn != null)
conn.close();
} catch (SQLException se) {
se.printStackTrace();
}
}
}
}
}
}