[Java知识库] 自定义MVC

开发: C++知识库 Java知识库 JavaScript Python PHP知识库人工智能区块链大数据移动开发嵌入式开发工具数据结构与算法开发测试游戏开发网络协议系统运维
教程: HTML教程 CSS教程 JavaScript教程 Go语言教程 JQuery教程 VUE教程 VUE3教程 Bootstrap教程 SQL数据库教程 C语言教程 C++教程 Java教程 Python教程 Python3教程 C#教程
数码: 电脑笔记本显卡显示器固态硬盘硬盘耳机手机 iphone vivo oppo 小米华为单反装机图拉丁

-> Java知识库 -> 自定义MVC -> 正文阅读

[Java知识库]自定义MVC

1.思维导图

?2.代码

?
<%@ 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>
</head>
<body>
目前多数人增删改查的代码
<a href="${pageContext.request.contextPath }/book/add">增加</a>
<a href="${pageContext.request.contextPath }/book/delete">删除</a>
<a href="${pageContext.request.contextPath }/book/edit">修改</a>
<a href="${pageContext.request.contextPath }/book/list">查询</a>
<hr>

增删改查的代码V2.0
<a href="${pageContext.request.contextPath }/book.action?methodName=add">增加</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=delete">删除</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=edit">修改</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=list">查询</a>
<hr>
增删改查的代码V3.0
<a href="${pageContext.request.contextPath }/book.action?methodName=load">回显</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=ref">关联</a>
</body>
</html>

package com.zking.framework;

import java.lang.reflect.Method;

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

public class ActionSupport implements Action{

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp) {
		
		String methodName = req.getParameter("methodName");
		try {
			Method m = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
			m.setAccessible(true);//访问权限
			m.invoke(this, req,resp);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

package com.zking.framework;

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

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

import com.zking.web.BookAction;
/**
 * 目标：
 * 根据自定义mvc框架的原理图完成	框架的研发
 * @author zjjt
 *中央控制器
 *寻找子控制器
 */
@WebServlet("*.action")
public class DispatchServlet extends HttpServlet{
	
	//放子控制器的容器
	private Map<String, ActionSupport> actions=new HashMap<String, ActionSupport>();
	//初始化子控制器容器（集合）,经过初始化，actions容器内存就有了子控制器
	//init,service,destroy
	
	@Override
	public void init() throws ServletException {
		actions.put("/book", new BookAction());
		/*actions.put("/order", new BookAction());
		actions.put("/OrderItem", new BookAction());*/
	}
	
	@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 {
		//完成寻找子控制的过程
		//浏览器：http://localhost:8080/t266_mvc/book.action?methodName=add
		//目标：BookAction.add()..
		/**
		 * 思路：
		 * 1.从游览器URL中获取到“/book”字符串
		 * 2.在子控制器容器中拿到BookAction
		 * 3.BookAction.add()
		 */
		String uri = req.getRequestURI();
		uri = uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));
		//action=BookAction
		ActionSupport action = actions.get(uri);
		//ActionSupport action=new BookAction()
		action.execute(req, resp);
	}
}