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Web体系结构与程序设计 实验5
2024-05-26
大学课程
00

目录

1 JSP 基础语法练习
2 EL 表达式应用
3 结合 JavaBean 构建动态页面
4 实验要求4～8
4.1 Model
4.2 Controller
4.3 View
4.4 整体效果

记录实验5过程及代码。

碎碎念：哥们是真的不会前端和c++，怎么最近就总能碰见这俩东西，而且JSP是真的不会，调试我都懵圈不知道怎么调，直接问AI让它帮我写了。

提示

这次实验需要引入JSTL库，我的Tomcat 10对应的JSTL的maven依赖：

xml
<dependency>
    <groupId>org.glassfish.web</groupId>
    <artifactId>jakarta.servlet.jsp.jstl</artifactId>
    <version>2.0.0</version>
</dependency>

<dependency>
    <groupId>org.apache.taglibs</groupId>
    <artifactId>taglibs-standard-spec</artifactId>
    <version>1.2.5</version>
</dependency>

Tomcat 9及以下用的JSTL库就不一样了，建议根据自己的项目的管理方式和Tomcat版本进行查询。

1 JSP 基础语法练习

html
<%-- experiment5_1.jsp --%>
<%--
  Created by IntelliJ IDEA.
  User: Misaka19327
  Date: 2024/5/25
  Time: 20:44
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>

<%
    String test1 = "Test Out Info";
    System.out.println(test1);
%>

<jsp:useBean id="person" class="org.example.webstructure.experiment5.Person" scope="session"/>

<jsp:setProperty name="person" property="name" value="John"/>
<jsp:setProperty name="person" property="age" value="30"/>

<p>
    姓名：
    <jsp:getProperty name="person" property="name"/>
    <br/>
    年龄：
    <jsp:getProperty name="person" property="age"/>
</p>

</body>
</html>

image.png

2 EL 表达式应用

html
<%-- experiment5_2.jsp --%>
<%--
  Created by IntelliJ IDEA.
  User: Misaka19327
  Date: 2024/5/25
  Time: 20:53
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>EL表达式示例</h1>

<%-- 获取请求参数 --%>
<c:set var="paramValue" value="${param.paramName}"/>

<%-- 获取Session属性 --%>
<c:set var="attributeValue" value="${sessionScope.attributeName}"/>

<%-- 获取Application范围内的共享数据 --%>
<c:set var="attributeValue" value="${applicationScope.attributeName}"/>

<%-- 条件显示 --%>
<c:if test="${not empty param.paramName}">
    <p>请求参数存在</p>
</c:if>

<%-- 列表遍历 --%>
<%-- 假设名为 "list" 的列表已在后台设置 --%>
<jsp:useBean id="list" scope="request" type="java.util.List"/>
<c:forEach var="item" items="${list}">
    <p>${item}</p>
</c:forEach>
</body>
</html>

java
// Experiment5_2.java
package org.example.webstructure.experiment5;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

@WebServlet(value = "/ELExample")
public class Experiment5_2 extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 设置请求参数
        request.setAttribute("paramName", "paramValue");

        // 设置Session属性
        request.getSession().setAttribute("attributeName", "attributeValue");

        // 设置Application范围内的共享数据
        getServletContext().setAttribute("attributeName", "attributeValue");

        // 设置列表数据
        List<String> list = new ArrayList<>();
        list.add("Item 1");
        list.add("Item 2");
        list.add("Item 3");
        request.setAttribute("list", list);

        // 转发到JSP页面
        request.getRequestDispatcher("Experiment5/experiment5_2.jsp").forward(request, response);
    }
}

image.png

3 结合 JavaBean 构建动态页面

html
<%-- experiment5_3.jsp --%>
<%--
  Created by IntelliJ IDEA.
  User: Misaka19327
  Date: 2024/5/25
  Time: 21:35
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>JavaBean示例</h1>

<h2>从请求作用域获取JavaBean数据:</h2>
<p>Name: ${person.name}</p>
<p>Age: ${person.age}</p>

<h2>从会话作用域获取JavaBean数据:</h2>
<p>Name: ${sessionScope.person.name}</p>
<p>Age: ${sessionScope.person.age}</p>
</body>
</html>

java
// Person.java
package org.example.webstructure.experiment5;

import java.beans.JavaBean;

@JavaBean
public class Person {
    private String name;
    private int age;

    public Person() {
    }

    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;
    }
}

java
// Experiment5_3.java
package org.example.webstructure.experiment5;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet(value = "/Experiment5_3")
public class Experiment5_3 extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 创建JavaBean对象
        Person person = new Person();

        // 设置JavaBean的属性
        person.setName("TestName");
        person.setAge(24);

        // 将JavaBean放入请求作用域
        request.setAttribute("person", person);

        // 将JavaBean放入会话作用域
        request.getSession().setAttribute("person", person);

        // 转发到JSP页面
        request.getRequestDispatcher("Experiment5/experiment5_3.jsp").forward(request, response);
    }
}

image.png

4 实验要求4～8

4.1 Model

java
// UserEntity.java
package org.example.webstructure.experiment5;

import java.beans.JavaBean;

@JavaBean
public class UserEntity {
    private String userName;
    private String password;

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

java
// UserDAO.java
package org.example.webstructure.experiment5;


import java.sql.*;

public class UserDAO {
    Connection connection;

    public UserDAO() throws SQLException, ClassNotFoundException {
        Class.forName("com.mysql.jdbc.Driver");
        connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:19327/test", "root", "123456");
    }

    public boolean checkPassword (UserEntity user) throws SQLException {
        PreparedStatement preparedStatement = connection.prepareStatement("select userPassword from userinfo where userName = ?");
        preparedStatement.setString(1, user.getUserName());
        ResultSet result = preparedStatement.executeQuery();
        result.next();
        return result.getString(1).equals(user.getPassword());
    }

    public boolean addUser (UserEntity user) throws SQLException {
        PreparedStatement preparedStatement = connection.prepareStatement("insert into userinfo (userName, userPassword) value (?, ?)");
        preparedStatement.setString(1, user.getUserName());
        preparedStatement.setString(2, user.getPassword());
        int result = preparedStatement.executeUpdate();
        return result == 1;
    }
}

sql
CREATE TABLE `userinfo` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `userName` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
  `userPassword` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

insert into userinfo (userName, userPassword) value (这里想填啥用户名和密码就填啥);

4.2 Controller

java
// EnrollController.java
package org.example.webstructure.experiment5;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.MultipartConfig;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.Part;

import java.io.IOException;
import java.io.Writer;
import java.sql.SQLException;

@WebServlet(value = "/experiment5_enroll")
@MultipartConfig
public class EnrollController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html");
        RequestDispatcher dispatcher = req.getRequestDispatcher("Experiment5/enroll.jsp");
        dispatcher.forward(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String userName, userPassword;
        userName = req.getParameter("userName");
        userPassword = req.getParameter("userPassword");

        UserEntity user = new UserEntity();
        user.setUserName(userName);
        user.setPassword(userPassword);
        Writer writer = resp.getWriter();
        try {
            UserDAO dao = new UserDAO();
            if (dao.addUser(user)) {
                writer.write("Enroll Successful");
            } else {
                writer.write("Enroll Failed");
            }
        } catch (SQLException | ClassNotFoundException e) {
            writer.write(e.getMessage());
            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }
}

java
// LoginController.java
package org.example.webstructure.experiment5;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.MultipartConfig;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.Part;

import java.io.IOException;
import java.io.Writer;
import java.sql.SQLException;

@WebServlet(value = "/experiment5_login")
@MultipartConfig
public class LoginController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html");
        RequestDispatcher dispatcher = req.getRequestDispatcher("Experiment5/login.jsp");
        dispatcher.forward(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String userName, userPassword;
        userName = req.getParameter("userName");
        userPassword = req.getParameter("userPassword");

        UserEntity user = new UserEntity();
        user.setUserName(userName);
        user.setPassword(userPassword);
        Writer writer = resp.getWriter();
        try {
            log(user.getPassword());
            UserDAO dao = new UserDAO();
            if (dao.checkPassword(user)) {
                writer.write("Login Successful");
            } else {
                writer.write("Login Failed");
            }
        } catch (SQLException | ClassNotFoundException e) {
            writer.write(e.getMessage());
            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }
}

4.3 View

html
<%-- enroll.jsp --%>
<%--
  Created by IntelliJ IDEA.
  User: Misaka19327
  Date: 2024/5/26
  Time: 9:40
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Enroll</title>
</head>
<body>
<h1>Enroll</h1>
<form action="${pageContext.request.contextPath}//experiment5_enroll" method="post">
    <label for="userName">Username:</label>
    <input type="text" name="userName" id="userName" required><br>

    <label for="userPassword">Password:</label>
    <input type="password" name="userPassword" id="userPassword" required><br>

    <input type="submit" value="Enroll">
</form>
</body>
</html>

html
<%-- login.jsp --%>
<%--
  Created by IntelliJ IDEA.
  User: Misaka19327
  Date: 2024/5/26
  Time: 9:41
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Login</title>
</head>
<body>
<h1>Login</h1>
<h1></h1>
<form action="${pageContext.request.contextPath}//experiment5_login" method="post">
    <label for="userName">Username:</label>
    <input type="text" name="userName" id="userName" required><br>

    <label for="userPassword">Password:</label>
    <input type="password" name="userPassword" id="userPassword" required><br>

    <input type="submit" value="Login">
</form>
</body>
</html>

4.4 整体效果

image.png

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