基于Servlet+JSP+Mysql的简易学生管理功能,实现增删改查代码

由于您没有提供具体的需求和数据结构，以下是一个基于Servlet+JSP+Mysql的简易学生管理功能的示例代码：

1. 创建数据库表

首先，我们需要在Mysql中创建一个学生表，可以使用以下SQL语句：

CREATE TABLE student (
  id INT(11) NOT NULL AUTO_INCREMENT,
  name VARCHAR(100) NOT NULL,
  age INT(11) NOT NULL,
  gender VARCHAR(10) NOT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

2. 编写JavaBean

接下来，我们需要创建一个JavaBean，用于封装学生信息。可以使用以下代码：

public class Student {
    private int id;
    private String name;
    private int age;
    private String gender;

    public Student() {
    }

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

    // getter and setter methods

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }
}

3. 编写DAO类

接下来，我们需要创建一个DAO类，用于操作学生表。可以使用以下代码：

public class StudentDAO {
    private Connection conn;

    public StudentDAO() {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url = "jdbc:mysql://localhost:3306/student?useUnicode=true&characterEncoding=utf8&useSSL=false";
            String user = "root";
            String password = "root";
            conn = DriverManager.getConnection(url, user, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public List<Student> getAllStudents() {
        List<Student> students = new ArrayList<>();
        String sql = "SELECT * FROM student";
        try {
            PreparedStatement ps = conn.prepareStatement(sql);
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                String gender = rs.getString("gender");
                Student student = new Student(id, name, age, gender);
                students.add(student);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return students;
    }

    public void addStudent(Student student) {
        String sql = "INSERT INTO student(name, age, gender) VALUES (?, ?, ?)";
        try {
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setString(1, student.getName());
            ps.setInt(2, student.getAge());
            ps.setString(3, student.getGender());
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void deleteStudent(int id) {
        String sql = "DELETE FROM student WHERE id=?";
        try {
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void updateStudent(Student student) {
        String sql = "UPDATE student SET name=?, age=?, gender=? WHERE id=?";
        try {
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setString(1, student.getName());
            ps.setInt(2, student.getAge());
            ps.setString(3, student.getGender());
            ps.setInt(4, student.getId());
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public Student getStudentById(int id) {
        String sql = "SELECT * FROM student WHERE id=?";
        try {
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            ResultSet rs = ps.executeQuery();
            if (rs.next()) {
                String name = rs.getString("name");
                int age = rs.getInt("age");
                String gender = rs.getString("gender");
                Student student = new Student(id, name, age, gender);
                return student;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}

4. 编写Servlet类

接下来，我们需要创建一个Servlet类，用于接收用户请求并调用DAO类来操作数据库。可以使用以下代码：

public class StudentServlet extends HttpServlet {
    private StudentDAO studentDAO;

    public void init() {
        studentDAO = new StudentDAO();
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if (action == null) {
            action = "list";
        }
        switch (action) {
            case "list":
                listStudents(request, response);
                break;
            case "add":
                addStudent(request, response);
                break;
            case "delete":
                deleteStudent(request, response);
                break;
            case "edit":
                editStudent(request, response);
                break;
            case "update":
                updateStudent(request, response);
                break;
            default:
                listStudents(request, response);
                break;
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    private void listStudents(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List<Student> students = studentDAO.getAllStudents();
        request.setAttribute("students", students);
        RequestDispatcher dispatcher = request.getRequestDispatcher("/list.jsp");
        dispatcher.forward(request, response);
    }

    private void addStudent(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String name = request.getParameter("name");
        int age = Integer.parseInt(request.getParameter("age"));
        String gender = request.getParameter("gender");
        Student student = new Student(0, name, age, gender);
        studentDAO.addStudent(student);
        response.sendRedirect("student?action=list");
    }

    private void deleteStudent(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        studentDAO.deleteStudent(id);
        response.sendRedirect("student?action=list");
    }

    private void editStudent(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        Student student = studentDAO.getStudentById(id);
        request.setAttribute("student", student);
        RequestDispatcher dispatcher = request.getRequestDispatcher("/edit.jsp");
        dispatcher.forward(request, response);
    }

    private void updateStudent(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        String name = request.getParameter("name");
        int age = Integer.parseInt(request.getParameter("age"));
        String gender = request.getParameter("gender");
        Student student = new Student(id, name, age, gender);
        studentDAO.updateStudent(student);
        response.sendRedirect("student?action=list");
    }
}

5. 编写JSP页面

最后，我们需要创建两个JSP页面，用于显示学生列表和编辑学生信息。可以使用以下代码：

list.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>学生列表</title>
</head>
<body>
    <h1>学生列表</h1>
    <table border="1">
        <tr>
            <th>ID</th>
            <th>姓名</th>
            <th>年龄</th>
            <th>性别</th>
            <th>操作</th>
        </tr>
        <c:forEach var="student" items="${students}">
            <tr>
                <td>${student.id}</td>
                <td>${student.name}</td>
                <td>${student.age}</td>
                <td>${student.gender}</td>
                <td>
                    <a href="student?action=edit&id=${student.id}">编辑</a>
                    <a href="student?action=delete&id=${student.id}">删除</a>
                </td>
            </tr>
        </c:forEach>
    </table>
    <br>
    <a href="add.jsp">添加学生</a>
</body>
</html>

edit.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>编辑学生信息</title>
</head>
<body>
    <h1>编辑学生信息</h1>
    <form action="student?action=update" method="post">
        <input type="hidden" name="id" value="${student.id}">
        姓名：<input type="text" name="name" value="${student.name}"><br>
        年龄：<input type="text" name="age" value="${student.age}"><br>
        性别：<input type="text" name="gender" value="${student.gender}"><br>
        <input type="submit" value="保存">
    </form>
</body>
</html>

6. 部署和运行

将以上代码保存在一个Java Web项目中，并部署到Tomcat服务器上。访问http://localhost:8080/项目名/student?action=list 即可浏览学生列表。