自定义mvc框架

最新推荐文章于 2025-12-19 15:50:30 发布

原创最新推荐文章于 2025-12-19 15:50:30 发布 · 107 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#大数据

本文档展示了如何构建一个简单的MVC框架，包括实体类`Book`、`Action`接口、`ActionModel`、`ActionSupport`及`DispatcherServlet`。`DispatcherServlet`作为中央控制器负责根据请求找到对应的处理人，并通过反射调用相应方法。配置文件部分展示了`config.xml`的结构，用于定义不同的`action`及其对应的页面跳转。整个框架实现了动态加载配置和模型驱动的功能，便于页面跳转和数据处理。

一、实体类

Book:

package com.hz.entity;

public class Book {
	private int bid;
	private String bname;
	private float price;
	public int getBid() {
		return bid;
	}
	public void setBid(int bid) {
		this.bid = bid;
	}
	public String getBname() {
		return bname;
	}
	public void setBname(String bname) {
		this.bname = bname;
	}
	public float getPrice() {
		return price;
	}
	public void setPrice(float price) {
		this.price = price;
	}
	public Book() {
		// TODO Auto-generated constructor stub
	}
	@Override
	public String toString() {
		return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
	}
	
}

二、framework框架

1、Action

package com.hz.framework;

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

/**
 * 子控制器：
 * 	对应请求的处理人
 * @author xnx
 *
 * 2022年6月25日上午9:13:00
 */
public interface Action {
	String execute(HttpServletRequest req, HttpServletResponse resp);
}

2、ActionModel

package com.hz.framework;

import java.util.HashMap;
import java.util.Map;

/**
 * 对应action标签
 * @author xnx
 *
 * 2022年6月14日下午4:37:31
 */
public class ActionModel {
//	<action path="/loginAction" type="test.LoginAction">
	private String path;
	private String type;
	private Map<String, ForwardModel> fMap=new HashMap<String, ForwardModel>();
	public String getPath() {
		return path;
	}
	public void setPath(String path) {
		this.path = path;
	}
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
//	两个行为，增加forwardModel对象，查找forwardModel对象
//	将一个新的forward标签对象加入容器
	public void push(ForwardModel forwardModel) {
		fMap.put(forwardModel.getName(), forwardModel);
	}
	public ForwardModel pop(String name) {
		return fMap.get(name);
	}
}

3、ActionSupport

package com.hz.framework;

import java.lang.reflect.Method;

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

public class ActionSupport implements Action{

	@Override
	public String execute(HttpServletRequest req, HttpServletResponse resp) {
		String methodName = req.getParameter("methodName");
//		methodName可以能是a dd/del/edit/list/load/xxx/yyy/aaa...
//		前台传递说明方法，就调用当前类的对应方法
		try {
			Method m = this.getClass()// BookServlet.class
				.getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
			m.setAccessible(true);
//			调用当前类实例的methodName方法
			return (String) m.invoke(this, req,resp);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	
}

4、ConfigModel

package com.hz.framework;

import java.util.HashMap;
import java.util.Map;

/**
 * 对应config标签
 * @author xnx
 *
 * 2022年6月14日下午4:36:46
 */
public class ConfigModel {
	private Map<String, ActionModel> aMap=new HashMap<String, ActionModel>();
	public void push(ActionModel actionModel) {
		aMap.put(actionModel.getPath(), actionModel);
	}
	public ActionModel pop(String path) {
		return aMap.get(path);
	}
}

3.返回值页面跳转优化

package com.hz.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 org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.PropertyUtils;

import com.hz.web.BookAction;

/**
 * 中央控制器
 * 	主要职能：接收浏览器请求，找到对应的处理人
 * 
 * @author Administrator
 *
 */
@WebServlet("*.action")
public class DispatcherServlet extends HttpServlet{
//	private Map<String, Action> action=new HashMap<String, Action>();

	/**
	 *
	 * 通过建模我们可以知道，最终configModel对象会包含config.xml中的所有子控制器信息	
	 	同时为了解决中央控制器能够动态加载子控制器的信息，那么我们只需引入congigModel对象即可
	 */
	
	private ConfigModel configModel;
	
//	程序启动时只会加载一次
	@Override
	public void init() throws ServletException {
//		action.("/book", new BookAction());
		try {
//			配置地址
//			
			String configLocation = this.getInitParameter("configLocation");
			if(configLocation==null || "".equals(configLocation)) {
				configModel = ConfiigModelFactory.bulid();
			}
			else {
				configModel = ConfiigModelFactory.bulid(configLocation);
			}
			configModel=ConfiigModelFactory.bulid();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	@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 {
		//http//localhost:8080/mvc/book.action?methodName=list
		String uri = req.getRequestURI();
//		要拿到/book. 接收最后一个/到最后一个点的位置
		uri=uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));
		
//		Action action2 = action.get(uri);
//		相比于上一种从map集合获取子控制器，当前需要获取config.xml中的全路径名，然后反射实例化
		ActionModel actionModel = configModel.pop(uri);
		if(actionModel==null) {
			throw new RuntimeException("action 配置错误");
		}
		String type = actionModel.getType();
		try {
//		type是子控制器全路径名
			Action action = (Action) Class.forName(type).newInstance();
//		action是bookAction 
			if(action instanceof ModelDriven) {
				ModelDriven md=(ModelDriven) action;
//				model指的是bookAction的实类	
				Object model = md.getModel();
//				要始model中的属性赋值，要接受前段jsp参数
//				PropertyUtils.getProperty(bean, name)
//				将前台所有的参数封装进实体类
				BeanUtils.populate(model, req.getParameterMap());
				System.out.println(model);
				
			}
			
			
//			正式通用方法前，book中的属性药被赋值
			String result = action.execute(req, resp);
			ForwarModel forwarModel = actionModel.pop(result);
//			if(forwarModel==null) {
//				throw new RuntimeException("foreard config error");
//			}
//			/booklist
			String path = forwarModel.getPath();
//			拿到是否需要转发的配置 
			boolean redirect = forwarModel.isRedirect();
			if(redirect) {
				resp.sendRedirect(req.getServletContext().getContextPath() + path);
			}
			else {
				
				req.getRequestDispatcher(path).forward(req, resp);
			}
			req.getRequestDispatcher(path).forward(req, resp);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

4.框架配置文件可变

<?xml version="1.0" encoding="UTF-8"?>
	<!--
		config标签:可以包含0~N个action标签
	-->
<config>
	
	<action path ="/book" type="com.hz.web.BookAction">
		<forward name="success" path="/demo2.jsp" redirect="false" />
		<forward name="failed" path="/demo3.jsp" redirect="true" />
	</action>
	
	<action path="/order" type="com.hz.web.OrderServlet">
		<forward name="failed" path="/login.jsp" redirect="false" />
		<forward name="success" path="/main.jsp" redirect="true" />
	
	</action>
</config>