IDEA+Java+JSP+Mysql+Tomcat写一个Web学生信息管理系统

为了写一个基于IDEA、Java、JSP、MySQL和Tomcat的Web学生信息管理系统，你可以按照以下步骤进行：

1. 创建一个Maven项目，项目结构如下：

|--src
|  |--main
|  |  |--java
|  |  |  |--com.example.student
|  |  |  |  |--db // 数据库相关类
|  |  |  |  |--model // 实体类
|  |  |  |  |--servlet // Servlet类
|  |  |  |--resources
|  |  |  |--webapp // JSP页面和静态资源
|  |  |--webapp // Web资源
|  |--test
|  |  |--java
|--pom.xml

2. 在MySQL中创建一个名为“student”的数据库，然后创建一个名为“students”的表，表结构如下：

CREATE TABLE students (
  id INT PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(50) NOT NULL,
  gender VARCHAR(10) NOT NULL,
  age INT NOT NULL,
  major VARCHAR(50) NOT NULL,
  grade INT NOT NULL
);

3. 在db包下创建一个名为“DBUtil”的工具类，用于连接数据库。代码如下：

package com.example.student.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBUtil {
    private static final String URL = "jdbc:mysql://localhost:3306/student";
    private static final String USER = "root";
    private static final String PASSWORD = "root";

    public static Connection getConnection() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

4. 在model包下创建一个名为“Student”的实体类，代码如下：

package com.example.student.model;

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

    public Student() {
    }

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

    // getter和setter方法省略
}

5. 在servlet包下创建一个名为“StudentServlet”的Servlet类，用于处理前端传来的请求。代码如下：

package com.example.student.servlet;

import com.example.student.db.DBUtil;
import com.example.student.model.Student;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

@WebServlet(name = "StudentServlet", urlPatterns = "/student")
public class StudentServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String action = req.getParameter("action");
        if ("add".equals(action)) {
            // 处理学生信息添加请求
            String name = req.getParameter("name");
            String gender = req.getParameter("gender");
            int age = Integer.parseInt(req.getParameter("age"));
            String major = req.getParameter("major");
            int grade = Integer.parseInt(req.getParameter("grade"));
            Student student = new Student(0, name, gender, age, major, grade);
            addStudent(student);
            resp.sendRedirect(req.getContextPath() + "/student");
        } else if ("edit".equals(action)) {
            // 处理学生信息编辑请求
            int id = Integer.parseInt(req.getParameter("id"));
            String name = req.getParameter("name");
            String gender = req.getParameter("gender");
            int age = Integer.parseInt(req.getParameter("age"));
            String major = req.getParameter("major");
            int grade = Integer.parseInt(req.getParameter("grade"));
            Student student = new Student(id, name, gender, age, major, grade);
            updateStudent(student);
            resp.sendRedirect(req.getContextPath() + "/student");
        } else if ("delete".equals(action)) {
            // 处理学生信息删除请求
            int id = Integer.parseInt(req.getParameter("id"));
            deleteStudent(id);
            resp.sendRedirect(req.getContextPath() + "/student");
        } else {
            // 处理学生信息列表请求
            List<Student> students = getAllStudents();
            req.setAttribute("students", students);
            req.getRequestDispatcher("/WEB-INF/views/student.jsp").forward(req, resp);
        }
    }

    private List<Student> getAllStudents() {
        List<Student> students = new ArrayList<>();
        try (Connection conn = DBUtil.getConnection();
             Statement stmt = conn.createStatement()) {
            String sql = "SELECT * FROM students";
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String gender = rs.getString("gender");
                int age = rs.getInt("age");
                String major = rs.getString("major");
                int grade = rs.getInt("grade");
                Student student = new Student(id, name, gender, age, major, grade);
                students.add(student);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return students;
    }

    private void addStudent(Student student) {
        try (Connection conn = DBUtil.getConnection();
             PreparedStatement stmt = conn.prepareStatement("INSERT INTO students (name, gender, age, major, grade) VALUES (?, ?, ?, ?, ?)")) {
            stmt.setString(1, student.getName());
            stmt.setString(2, student.getGender());
            stmt.setInt(3, student.getAge());
            stmt.setString(4, student.getMajor());
            stmt.setInt(5, student.getGrade());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private void updateStudent(Student student) {
        try (Connection conn = DBUtil.getConnection();
             PreparedStatement stmt = conn.prepareStatement("UPDATE students SET name=?, gender=?, age=?, major=?, grade=? WHERE id=?")) {
            stmt.setString(1, student.getName());
            stmt.setString(2, student.getGender());
            stmt.setInt(3, student.getAge());
            stmt.setString(4, student.getMajor());
            stmt.setInt(5, student.getGrade());
            stmt.setInt(6, student.getId());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private void deleteStudent(int id) {
        try (Connection conn = DBUtil.getConnection();
             PreparedStatement stmt = conn.prepareStatement("DELETE FROM students WHERE id=?")) {
            stmt.setInt(1, id);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

6. 在webapp目录下创建一个名为“student.jsp”的JSP页面，用于显示学生信息列表和处理学生信息的添加、编辑和删除等操作。代码如下：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>学生信息管理系统</title>
</head>
<body>
<h1>学生信息管理系统</h1>
<table border="1">
    <tr>
        <th>ID</th>
        <th>姓名</th>
        <th>性别</th>
        <th>年龄</th>
        <th>专业</th>
        <th>年级</th>
        <th>操作</th>
    </tr>
    <c:forEach items="${students}" var="student">
        <tr>
            <td>${student.id}</td>
            <td>${student.name}</td>
            <td>${student.gender}</td>
            <td>${student.age}</td>
            <td>${student.major}</td>
            <td>${student.grade}</td>
            <td>
                <a href="${pageContext.request.contextPath}/student?action=edit&id=${student.id}">编辑</a>
                <a href="${pageContext.request.contextPath}/student?action=delete&id=${student.id}">删除</a>
            </td>
        </tr>
    </c:forEach>
</table>
<h2>添加学生信息</h2>
<form method="post" action="${pageContext.request.contextPath}/student?action=add">
    <div>
        <label for="name">姓名：</label>
        <input type="text" id="name" name="name" required>
    </div>
    <div>
        <label for="gender">性别：</label>
        <input type="radio" id="gender" name="gender" value="男" required>男
        <input type="radio" id="gender" name="gender" value="女" required>女
    </div>
    <div>
        <label for="age">年龄：</label>
        <input type="number" id="age" name="age" required>
    </div>
    <div>
        <label for="major">专业：</label>
        <input type="text" id="major" name="major" required>
    </div>
    <div>
        <label for="grade">年级：</label>
        <input type="number" id="grade" name="grade" required>
    </div>
    <div>
        <button type="submit">添加</button>
    </div>
</form>
<c:if test="${not empty param.id}">
    <h2>编辑学生信息</h2>
    <form method="post" action="${pageContext.request.contextPath}/student?action=edit&id=${param.id}">
        <div>
            <label for="name">姓名：</label>
            <input type="text" id="name" name="name" value="${student.name}" required>
        </div>
        <div>
            <label for="gender">性别：</label>
            <input type="radio" id="gender" name="gender" value="男" ${student.gender=='男'?'checked':''} required>男
            <input type="radio" id="gender" name="gender" value="女" ${student.gender=='女'?'checked':''} required>女
        </div>
        <div>
            <label for="age">年龄：</label>
            <input type="number" id="age" name="age" value="${student.age}" required>
        </div>
        <div>
            <label for="major">专业：</label>
            <input type="text" id="major" name="major" value="${student.major}" required>
        </div>
        <div>
            <label for="grade">年级：</label>
            <input type="number" id="grade" name="grade" value="${student.grade}" required>
        </div>
        <div>
            <button type="submit">保存</button>
        </div>
    </form>
</c:if>
</body>
</html>

7. 在pom.xml文件中添加以下依赖：

<dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.26</version>
    </dependency>
</dependencies>

8. 在Tomcat中部署该项目，启动Tomcat服务，通过浏览器访问项目的根路径，即可看到学生信息管理系统的页面。

以上是一个基本的实现过程，具体实现过程中还需要根据实际情况进行相应的调整和优化。