javaweb学生信息管理系统用到的核心代码

以下是一个简单的JavaWeb学生信息管理系统的核心代码，包括数据库连接、查询和更新操作：

1. 数据库连接代码：

public class DBUtil {
    private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/student";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "123456";

    public static Connection getConnection() throws ClassNotFoundException, SQLException {
        Class.forName(DRIVER);
        Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        return conn;
    }
}

2. 查询数据库中所有学生信息的代码：

public class StudentDao {
    public List<Student> getAllStudents() {
        List<Student> students = new ArrayList<Student>();
        String sql = "select * from student";
        try {
            Connection conn = DBUtil.getConnection();
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getInt("id"));
                student.setName(rs.getString("name"));
                student.setAge(rs.getInt("age"));
                student.setGender(rs.getString("gender"));
                student.setMajor(rs.getString("major"));
                students.add(student);
            }
            rs.close();
            stmt.close();
            conn.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return students;
    }
}

3. 向数据库中插入学生信息的代码：

public class StudentDao {
    public boolean addStudent(Student student) {
        boolean result = false;
        String sql = "insert into student(name, age, gender, major) values(?, ?, ?, ?)";
        try {
            Connection conn = DBUtil.getConnection();
            PreparedStatement stmt = conn.prepareStatement(sql);
            stmt.setString(1, student.getName());
            stmt.setInt(2, student.getAge());
            stmt.setString(3, student.getGender());
            stmt.setString(4, student.getMajor());
            int rows = stmt.executeUpdate();
            if (rows > 0) {
                result = true;
            }
            stmt.close();
            conn.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }
}