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
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
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。