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JavaWeb_MVC模式的简单demo

程序员文章站 2022-04-02 10:21:13
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JavaWeb_MVC模式的简单demo

本文通过实现简单的登录功能来介绍MVC模式

1. 项目的目录

JavaWeb_MVC模式的简单demo

2. login.jsp (包含一个表单，提交用户名、密码等信息)

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Login page</title>
</head>
<body>
    <form action="../login.do" method="post">
        <label>用户名 　</label><input type="text" name="userName" /><br /> <br />
        <label>密码　 　</label><input type="password" name="password" /><br /> <br />
        <input type="submit" value="登录" />
    </form>
</body>
</html>

3. UserBean.java (JavaBean文件,对应登录页面的表单信息)

package com.mxh.mvcdemo.demo1;

public class UserBean {
    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;
    }
}

4. Login.java (servlet类，接收login.jsp页面的请求，将表单信息封装到UserBean中，再将请求转发给hone.jsp页面，home.jsp页面作为响应页面返回客户端)

package com.mxh.mvcdemo.demo1;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class Login extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        resp.setCharacterEncoding("UTF-8");

        UserBean user = new UserBean();
        user.setUserName(req.getParameter("userName"));
        user.setPassword(req.getParameter("password"));

        req.setAttribute("user", user);

        RequestDispatcher view = req.getRequestDispatcher("/demo1/home.jsp");
        view.forward(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

5. web.xml (配置servlet类)

<servlet>
    <servlet-name>Login</servlet-name>
    <servlet-class>com.mxh.mvcdemo.demo1.Login</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>Login</servlet-name>
    <url-pattern>/login.do</url-pattern>
</servlet-mapping>

6. home.jsp (使用jstl标签输出用户表单提交的内容)

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Home Page</title>
</head>
<body>
    <jsp:useBean id="user" class="com.mxh.mvcdemo.demo1.UserBean" scope="request"></jsp:useBean>
    用户名：<jsp:getProperty property="userName" name="user"    /><br/>
    密码　：<jsp:getProperty property="password" name="user"    />
</body>
</html>

7. 程序运行效果图

JavaWeb_MVC模式的简单demo

JavaWeb_MVC模式的简单demo

8. 总结

jsp为视图层，servlet为控制器，javabean为模型。视图层的数据提交到控制器，控制器将数据封装到模型中，再由视图层操作模型输出数据。

相关标签： MVC JavaWeb Servlet JSP JavaBean

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