IntelliJ IDEA 如何代码实现学生信息、导师信息查询页面设计

要实现学生信息和导师信息查询页面设计，需要使用 Java Web 技术，并结合数据库进行数据的存储和查询。下面是一个简单的示例：

1. 创建一个 Maven 项目，并添加以下依赖：

<dependencies>
    <!-- Servlet API -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>

    <!-- JSP API -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2</version>
        <scope>provided</scope>
    </dependency>

    <!-- JSTL -->
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!-- MySQL JDBC -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.23</version>
    </dependency>
</dependencies>

2. 创建一个名为 `Student` 的 JavaBean 类，表示学生信息，包括学号、姓名和所属导师：

public class Student {
    private String id;
    private String name;
    private String advisor;

    // 省略 getter 和 setter 方法
}

3. 创建一个名为 `Advisor` 的 JavaBean 类，表示导师信息，包括姓名和联系方式：

public class Advisor {
    private String name;
    private String contact;

    // 省略 getter 和 setter 方法
}

4. 创建一个名为 `DatabaseUtil` 的工具类，用于连接数据库和执行 SQL 语句：

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

    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USER, PASSWORD);
    }

    public static void close(Connection conn, Statement stmt, ResultSet rs) throws SQLException {
        if (rs != null) {
            rs.close();
        }

        if (stmt != null) {
            stmt.close();
        }

        if (conn != null) {
            conn.close();
        }
    }

    public static void close(Connection conn, Statement stmt) throws SQLException {
        close(conn, stmt, null);
    }
}

5. 创建一个名为 `StudentDao` 的 DAO 类，用于操作学生信息的数据库表：

public class StudentDao {
    public List<Student> getAllStudents() throws SQLException {
        List<Student> students = new ArrayList<>();

        try (Connection conn = DatabaseUtil.getConnection();
             Statement stmt = conn.createStatement();
             ResultSet rs = stmt.executeQuery("SELECT * FROM students")) {
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getString("id"));
                student.setName(rs.getString("name"));
                student.setAdvisor(rs.getString("advisor"));
                students.add(student);
            }
        }

        return students;
    }

    public List<Student> getStudentsByAdvisor(String advisor) throws SQLException {
        List<Student> students = new ArrayList<>();

        try (Connection conn = DatabaseUtil.getConnection();
             PreparedStatement stmt = conn.prepareStatement("SELECT * FROM students WHERE advisor = ?")) {
            stmt.setString(1, advisor);

            try (ResultSet rs = stmt.executeQuery()) {
                while (rs.next()) {
                    Student student = new Student();
                    student.setId(rs.getString("id"));
                    student.setName(rs.getString("name"));
                    student.setAdvisor(rs.getString("advisor"));
                    students.add(student);
                }
            }
        }

        return students;
    }
}

6. 创建一个名为 `AdvisorDao` 的 DAO 类，用于操作导师信息的数据库表：

public class AdvisorDao {
    public List<Advisor> getAllAdvisors() throws SQLException {
        List<Advisor> advisors = new ArrayList<>();

        try (Connection conn = DatabaseUtil.getConnection();
             Statement stmt = conn.createStatement();
             ResultSet rs = stmt.executeQuery("SELECT * FROM advisors")) {
            while (rs.next()) {
                Advisor advisor = new Advisor();
                advisor.setName(rs.getString("name"));
                advisor.setContact(rs.getString("contact"));
                advisors.add(advisor);
            }
        }

        return advisors;
    }
}

7. 创建一个名为 `StudentServlet` 的 Servlet 类，用于处理学生信息查询请求：

@WebServlet("/students")
public class StudentServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private StudentDao studentDao;

    @Override
    public void init() throws ServletException {
        studentDao = new StudentDao();
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String advisor = request.getParameter("advisor");

        try {
            if (advisor == null) {
                List<Student> students = studentDao.getAllStudents();
                request.setAttribute("students", students);
                request.getRequestDispatcher("/WEB-INF/views/students.jsp").forward(request, response);
            } else {
                List<Student> students = studentDao.getStudentsByAdvisor(advisor);
                request.setAttribute("students", students);
                request.setAttribute("advisor", advisor);
                request.getRequestDispatcher("/WEB-INF/views/students_by_advisor.jsp").forward(request, response);
            }
        } catch (SQLException e) {
            e.printStackTrace();
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }
}

8. 创建一个名为 `AdvisorServlet` 的 Servlet 类，用于处理导师信息查询请求：

@WebServlet("/advisors")
public class AdvisorServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private AdvisorDao advisorDao;

    @Override
    public void init() throws ServletException {
        advisorDao = new AdvisorDao();
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        try {
            List<Advisor> advisors = advisorDao.getAllAdvisors();
            request.setAttribute("advisors", advisors);
            request.getRequestDispatcher("/WEB-INF/views/advisors.jsp").forward(request, response);
        } catch (SQLException e) {
            e.printStackTrace();
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }
}

9. 创建两个 JSP 页面，分别为 `students.jsp` 和 `students_by_advisor.jsp`，用于渲染学生信息查询结果：

`students.jsp`：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学生信息查询</title>
</head>
<body>
    <h1>学生信息查询</h1>

    <table border="1">
        <tr>
            <th>学号</th>
            <th>姓名</th>
            <th>所属导师</th>
        </tr>

        <c:forEach items="${students}" var="student">
            <tr>
                <td>${student.id}</td>
                <td>${student.name}</td>
                <td>${student.advisor}</td>
            </tr>
        </c:forEach>
    </table>

    <br>

    <a href="${pageContext.request.contextPath}/advisors">返回</a>
</body>
</html>

`students_by_advisor.jsp`：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学生信息查询</title>
</head>
<body>
    <h1>学生信息查询</h1>

    <h2>导师：${advisor}</h2>

    <table border="1">
        <tr>
            <th>学号</th>
            <th>姓名</th>
            <th>所属导师</th>
        </tr>

        <c:forEach items="${students}" var="student">
            <tr>
                <td>${student.id}</td>
                <td>${student.name}</td>
                <td>${student.advisor}</td>
            </tr>
        </c:forEach>
    </table>

    <br>

    <a href="${pageContext.request.contextPath}/students">返回</a>
</body>
</html>

10. 部署应用程序并启动 Tomcat 服务器，访问 `http://localhost:8080/项目名/advisors`，即可查看导师信息查询页面。选择一个导师，点击链接进入学生信息查询页面，即可查看该导师所带的学生信息。