java web MVC的实现(JSP+Servlet+javaBean)

时间:2022-02-19 19:08:47

MVC是三个单词的缩写:M,Model(模型);V,View( 视图 ),C,Control(控制)

MVC模式的目的就是实现Web系统的职能分工

Model层:实现系统的业务逻辑(javaBean)

View层:负责与用户交互,即在界面上展示数据对象给用户(html,jsp)

Control层:Model与View之间沟通的桥梁,它可以分派用户的请求并选择恰当的视图以用于显示,同时它也可以解释用户的输入并将它们映射为模型层可执行的操作(Servlet)


下面通过一个登录的实例体现MVC:

项目结构如下:

java web MVC的实现(JSP+Servlet+javaBean)

其中,login.jsp为登录页面;succes.jsp为登陆成功页面;unsuccessful.jsp为登录失败页面

login.jsp:

<body>
    <center>
      <form action="UserServlet" method="post">
        <h4>登录</h4>
        <hr/>
	          姓名:<input type="text" name="username"/><br/>
	          密码:<input type="password" name="password"/><br/>
        <input type="submit" value="提交"/> 
      </form>
    </center>
  </body>
success.jsp:

<body>
    <center>
      <h3>登陆成功</h3>
      <a href="<%=path %>/login.jsp">后退</a>
    </center>
  </body>
unsuccessful.jsp:
<body>
    <center>
      <h3>登陆失败</h3>
      <a href="<%=path %>/login.jsp">后退</a>
    </center>
  </body>


UserServlet.java(获取视图层传过来的参数,并传给模型层,待模型层判断后调转到相应的页面)

package com.mvc.servlet;

import java.io.IOException;

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

import com.mvc.javaBean.User;

public class UserServlet extends HttpServlet{

	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doPost(request, response);
	}

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		
		String userName = request.getParameter("username");
		String password = request.getParameter("password");
		
		User user = new User();
		if(user.validatorUser(userName, password)){
			response.sendRedirect("success.jsp");
		}
		else{
			response.sendRedirect("unsuccessful.jsp");
		}
	}
	
}

User.java(实现业务逻辑,即验证用户名与密码是否正确,在这里仅仅是验证字符串是否相等,姓名与密码都为“admin”时,登陆成功,也可以加上数据库连接代码)

package com.mvc.javaBean;

public class User {
	
	public boolean validatorUser(String username, String password){
		if(username.equals("admin") && password.equals("admin")){
			return true;
		}
		else{
			return false;
		}
	}
	
}

下面是web.xml的配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>MVC</display-name>
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>UserServlet</servlet-name>
    <servlet-class>com.mvc.servlet.UserServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>UserServlet</servlet-name>
    <url-pattern>/UserServlet</url-pattern>
  </servlet-mapping>
</web-app>


下面是具体演示:

java web MVC的实现(JSP+Servlet+javaBean)



java web MVC的实现(JSP+Servlet+javaBean)



java web MVC的实现(JSP+Servlet+javaBean)

在该实例中

Model层:User.java

View层:ogin.jsp;succes.jsp;unsuccessful.jsp

Control层:UserServlet.java

具体代码下载猛点下方java web MVC的实现(JSP+Servlet+javaBean)

http://download.csdn.net/detail/yezis/6937651