MVC之自定义框架【1】

最新推荐文章于 2025-05-26 16:53:33 发布

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最新推荐文章于 2025-05-26 16:53:33 发布

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本文链接：https://blog.youkuaiyun.com/weixin_43934140/article/details/90902078

自定义MVC【1】

什么是MVC

MVC全名是Model View Controller，是模型(model)－视图(view)－控制器(controller)的缩写，
它是一种软件设计典范，用一种业务逻辑、数据、界面显示分离的方法组织代码

核心思想：各司其职

req.getServletPath()	单纯的一个请求
req.getContextPath()	项目名
req.getRequestURI()	项目名+请求
req.getRequestURL()	请求的全路径

原理图：

在这里插入图片描述

mvc结构：
M
实体域模型(名词)
过程域模型(动词)
V
jsp/ios/android
C
servlet/action

注1：不能跨层调用
注2：只能出现由上而下的调用

那么接下来咱们做个计算器的demo：
创建实体类Cal

package com.wt.entity;

public class Cal {
	private String num1;
	private String num2;
	public String getNum1() {
		return num1;
	}
	public void setNum1(String num1) {
		this.num1 = num1;
	}
	public String getNum2() {
		return num2;
	}
	public void setNum2(String num2) {
		this.num2 = num2;
	}
	public Cal(String num1, String num2) {
		super();
		this.num1 = num1;
		this.num2 = num2;
	}
	public Cal() {
		super();
	}
	
}

其次咱们创建主控制器：

package com.wt.framework;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

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

import com.wt.web.AddCalAction;
import com.wt.web.DelCalAction;
import com.wt.web.cCalAction;
import com.wt.web.xCalAction;

/**
 * 主控制器
 * 	
 * @author MRCHENIKE
 *
 */
public class DispatcherServlet extends HttpServlet{

	private static final long serialVersionUID = 7986425427339711656L;
	
	private Map<String, Action> actionMap = new HashMap<>();
	
	public void init() {
		actionMap.put("/addCal", new AddCalAction());
		actionMap.put("/delCal", new DelCalAction());
		actionMap.put("/cCal", new cCalAction());
		actionMap.put("/xCal", new xCalAction());
	}
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		init();
		String url = req.getRequestURI(); //mvc/xxx.action
		url = url.substring(url.lastIndexOf("/"), url.lastIndexOf("."));
		Action action = actionMap.get(url);
		action.execute(req, resp);

	}
}

然后创建一个子控制器，同来处理用户的请求：

package com.wt.framework;

import java.io.IOException;

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

/**
 * 子控制器
 *   专门用来处理业务逻辑的
 * @author MRCHENIKE
 *
 */
public interface Action {
	 void execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException ;
}

接着咱们创建web层：
注意这里要实现子控制器
其余三个咱们就不一一演示了，只需要改一个运算符号就好了

package com.wt.web;

import java.io.IOException;

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

import com.wt.framework.Action;

public class AddCalAction implements Action {

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//加
		String num1 = req.getParameter("num1");
		String num2 = req.getParameter("num2");
		//负责运算 
		req.setAttribute("res", Integer.parseInt(num1)+Integer.parseInt(num2));
		req.getRequestDispatcher("calRes.jsp").forward(req, resp);
		
	}

}

这些都有了以后，还少了界面，那么咱们弄一个简单的计算器界面：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
	function doSub(val){
		if(val==1){
			calForm.action = "${pageContext.request.contextPath }/addCal.action";
		}
		else if(val==2){
			calForm.action = "${pageContext.request.contextPath }/delCal.action";
		}
		else if(val==3){
			calForm.action = "${pageContext.request.contextPath }/cCal.action";
		}
		else if(val==4){
			calForm.action = "${pageContext.request.contextPath }/xCal.action";
		}
		calForm.submit();
	}
</script>
</head>
<body>
	<form id="calForm" name="calForm" action="${pageContext.request.contextPath }/addCal.action">
		num1:<input type="text" name="num1"><br>
		num2:<input type="text" name="num2"><br>
		<button onclick="doSub(1)">+</button>
		<button onclick="doSub(2)">-</button>
		<button onclick="doSub(3)">*</button>
		<button onclick="doSub(4)">/</button>
	</form>
</body>
</html>

然后接受结果
在这里插入图片描述