用Java和mysql做一个简单的学生管理系统并且可以用页面操作

确实可以使用Java和MySQL来实现一个简单的学生管理系统，并且可以通过页面进行操作。这里给出一个简单的示例，该示例使用Java Servlet和JSP技术来实现网页界面，并使用MySQL存储数据。以下是实现步骤：

1. 创建一个名为`Student`的Java类，该类表示学生对象，包括学生ID、姓名和年龄等属性，以及对这些属性的读写方法。

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

    public Student() {
    }

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

    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;
    }
}

2. 创建一个名为`StudentDAO`的Java类，该类表示数据访问对象，负责管理学生对象的持久化存储。该类包括以下方法：

- `getConnection()`：获取数据库连接。
- `closeConnection(Connection conn)`：关闭数据库连接。
- `add(Student student)`：添加一个学生对象到数据库中。
- `delete(int id)`：从数据库中删除一个学生对象。
- `update(Student student)`：更新一个学生对象在数据库中的信息。
- `get(int id)`：从数据库中查找一个学生对象。
- `getAll()`：从数据库中获取所有的学生对象列表。

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

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

    public Connection getConnection() throws SQLException {
        Connection conn = null;
        try {
            Class.forName(DRIVER);
            conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return conn;
    }

    public void closeConnection(Connection conn) throws SQLException {
        if (conn != null) {
            conn.close();
        }
    }

    public void add(Student student) throws SQLException {
        Connection conn = getConnection();
        PreparedStatement ps = conn.prepareStatement("INSERT INTO student(name, age) VALUES(?, ?)");
        ps.setString(1, student.getName());
        ps.setInt(2, student.getAge());
        ps.executeUpdate();
        ps.close();
        closeConnection(conn);
    }

    public void delete(int id) throws SQLException {
        Connection conn = getConnection();
        PreparedStatement ps = conn.prepareStatement("DELETE FROM student WHERE id=?");
        ps.setInt(1, id);
        ps.executeUpdate();
        ps.close();
        closeConnection(conn);
    }

    public void update(Student student) throws SQLException {
        Connection conn = getConnection();
        PreparedStatement ps = conn.prepareStatement("UPDATE student SET name=?, age=? WHERE id=?");
        ps.setString(1, student.getName());
        ps.setInt(2, student.getAge());
        ps.setInt(3, student.getId());
        ps.executeUpdate();
        ps.close();
        closeConnection(conn);
    }

    public Student get(int id) throws SQLException {
        Connection conn = getConnection();
        PreparedStatement ps = conn.prepareStatement("SELECT * FROM student WHERE id=?");
        ps.setInt(1, id);
        ResultSet rs = ps.executeQuery();
        Student student = null;
        if (rs.next()) {
            student = new Student();
            student.setId(rs.getInt("id"));
            student.setName(rs.getString("name"));
            student.setAge(rs.getInt("age"));
        }
        rs.close();
        ps.close();
        closeConnection(conn);
        return student;
    }

    public List<Student> getAll() throws SQLException {
        Connection conn = getConnection();
        PreparedStatement ps = conn.prepareStatement("SELECT * FROM student");
        ResultSet rs = ps.executeQuery();
        List<Student> students = new ArrayList<>();
        while (rs.next()) {
            Student student = new Student();
            student.setId(rs.getInt("id"));
            student.setName(rs.getString("name"));
            student.setAge(rs.getInt("age"));
            students.add(student);
        }
        rs.close();
        ps.close();
        closeConnection(conn);
        return students;
    }
}

3. 创建一个名为`StudentServlet`的Java Servlet类，该类处理网页请求。该类包括以下方法：

- `doGet(HttpServletRequest request, HttpServletResponse response)`：处理GET请求，显示学生列表或单个学生信息。
- `doPost(HttpServletRequest request, HttpServletResponse response)`：处理POST请求，添加、修改或删除学生信息。

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

public class StudentServlet extends HttpServlet {
    private StudentDAO studentDAO = new StudentDAO();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String action = request.getParameter("action");
        if (action == null) {
            List<Student> students = null;
            try {
                students = studentDAO.getAll();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            request.setAttribute("students", students);
            request.getRequestDispatcher("/WEB-INF/views/student/list.jsp").forward(request, response);
        } else if (action.equals("add")) {
            request.getRequestDispatcher("/WEB-INF/views/student/add.jsp").forward(request, response);
        } else if (action.equals("edit")) {
            int id = Integer.parseInt(request.getParameter("id"));
            Student student = null;
            try {
                student = studentDAO.get(id);
            } catch (SQLException e) {
                e.printStackTrace();
            }
            request.setAttribute("student", student);
            request.getRequestDispatcher("/WEB-INF/views/student/edit.jsp").forward(request, response);
        } else if (action.equals("delete")) {
            int id = Integer.parseInt(request.getParameter("id"));
            try {
                studentDAO.delete(id);
            } catch (SQLException e) {
                e.printStackTrace();
            }
            response.sendRedirect(request.getContextPath() + "/student");
        } else {
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String action = request.getParameter("action");
        if (action.equals("add")) {
            String name = request.getParameter("name");
            int age = Integer.parseInt(request.getParameter("age"));
            Student student = new Student();
            student.setName(name);
            student.setAge(age);
            try {
                studentDAO.add(student);
            } catch (SQLException e) {
                e.printStackTrace();
            }
            response.sendRedirect(request.getContextPath() + "/student");
        } else if (action.equals("edit")) {
            int id = Integer.parseInt(request.getParameter("id"));
            String name = request.getParameter("name");
            int age = Integer.parseInt(request.getParameter("age"));
            Student student = new Student();
            student.setId(id);
            student.setName(name);
            student.setAge(age);
            try {
                studentDAO.update(student);
            } catch (SQLException e) {
                e.printStackTrace();
            }
            response.sendRedirect(request.getContextPath() + "/student");
        } else {
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }
}

4. 创建一个名为`list.jsp`的JSP文件，该文件显示学生列表和操作链接。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <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>操作</th>
    </tr>
    <c:forEach var="student" items="${students}">
        <tr>
            <td>${student.id}</td>
            <td>${student.name}</td>
            <td>${student.age}</td>
            <td>
                <a href="${pageContext.request.contextPath}/student?action=edit&id=${student.id}">编辑</a>
                <a href="${pageContext.request.contextPath}/student?action=delete&id=${student.id}">删除</a>
            </td>
        </tr>
    </c:forEach>
</table>
<br>
<a href="${pageContext.request.contextPath}/student?action=add">添加学生</a>
</body>
</html>

5. 创建一个名为`add.jsp`的JSP文件，该文件显示添加学生的表单。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加学生</title>
</head>
<body>
<h1>添加学生</h1>
<form action="${pageContext.request.contextPath}/student" method="post">
    <input type="hidden" name="action" value="add">
    <table>
        <tr>
            <td>姓名：</td>
            <td><input type="text" name="name"></td>
        </tr>
        <tr>
            <td>年龄：</td>
            <td><input type="text" name="age"></td>
        </tr>
        <tr>
            <td></td>
            <td><input type="submit" value="添加"></td>
        </tr>
    </table>
</form>
</body>
</html>

6. 创建一个名为`edit.jsp`的JSP文件，该文件显示编辑学生的表单。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>编辑学生</title>
</head>
<body>
<h1>编辑学生</h1>
<form action="${pageContext.request.contextPath}/student" method="post">
    <input type="hidden" name="action" value="edit">
    <input type="hidden" name="id" value="${student.id}">
    <table>
        <tr>
            <td>姓名：</td>
            <td><input type="text" name="name" value="${student.name}"></td>
        </tr>
        <tr>
            <td>年龄：</td>
            <td><input type="text" name="age" value="${student.age}"></td>
        </tr>
        <tr>
            <td></td>
            <td><input type="submit" value="保存"></td>
        </tr>
    </table>
</form>
</body>
</html>

7. 创建一个名为`web.xml`的Web应用程序部署描述文件，该文件指定Servlet和JSP文件的映射关系。

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <servlet>
        <servlet-name>StudentServlet</servlet-name>
        <servlet-class>StudentServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>StudentServlet</servlet-name>
        <url-pattern>/student</url-pattern>
    </servlet-mapping>
</web-app>

8. 将以上代码保存到对应的文件中，并将JSP文件放置到`/WEB-INF/views/student/`目录下。然后在本地MySQL数据库中创建一个名为`test`的数据库，运行以下SQL语句以创建学生表：

CREATE TABLE `student` (
    `id` INT NOT NULL AUTO_INCREMENT,
    `name` VARCHAR(20) NOT NULL,
    `age` INT NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

9. 最后，启动Tomcat服务器，访问`http://localhost:8080/项目名称/student`即可进入学生列表页面。从该页面可以添加、编辑和删除学生信息。