自定义MVC（二）

于 2019-12-30 10:13:27 发布
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本文链接：https://blog.youkuaiyun.com/zuo_fan/article/details/103760319
本文深入探讨MVC（Model-View-Controller）框架的设计原理，详细解析了配置模型、子控制器、中央控制器等核心组件的实现过程。通过具体案例，展示了如何利用MVC框架处理用户请求，实现业务逻辑与视图分离，提高代码的可维护性和复用性。

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对比参照MVC（一）
https://blog.youkuaiyun.com/zuo_fan/article/details/103557658
导入jar架包

在这里插入图片描述
创建4个工具类
（1）ActionModel：

package com.az.framework;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
/**
 * 用来描述action标签 
 * @author Administrator
 *
 */

public class ActionModel implements Serializable{ private static final long serialVersionUID = 6145949994701469663L;
 
 private Map<String, ForwardModel> forwardModels = new HashMap<String, ForwardModel>();
 
 private String path;
 
 private String type;
 
 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;
 } public void put(ForwardModel forwardModel){
  forwardModels.put(forwardModel.getName(), forwardModel);
 }
 
 public ForwardModel get(String name){
  return forwardModels.get(name);
 }
 
}

（2）ConfigModel ：

package com.az.framework;

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

/**
 * 
 * @author Administrator
 *
 */
public class ConfigModel implements Serializable{

	private static final long serialVersionUID = -2334963138078250952L;
	
	private Map<String, ActionModel> actionModels = new HashMap<String, ActionModel>();
	
	public void put(ActionModel actionModel){
		actionModels.put(actionModel.getPath(), actionModel);
	}
	
	public ActionModel get(String name){
		return actionModels.get(name);
	}
	
}

（3）ConfigModelFactory：

package com.az.framework;

import java.io.InputStream;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

public class ConfigModelFactory {
	private ConfigModelFactory() {

	}

	private static ConfigModel configModel = null;

	public static ConfigModel newInstance() throws Exception {
		return newInstance("mvc.xml");
	}

	/**
	 * 工厂模式创建config建模对象
	 * 
	 * @param path
	 * @return
	 * @throws Exception
	 */
	public static ConfigModel newInstance(String path) throws Exception {
		if (null != configModel) {
			return configModel;
		}

		ConfigModel configModel = new ConfigModel();
		InputStream is = ConfigModelFactory.class.getResourceAsStream(path);
		SAXReader saxReader = new SAXReader();
		Document doc = saxReader.read(is);
		List<Element> actionEleList = doc.selectNodes("/config/action");
		ActionModel actionModel = null;
		ForwardModel forwardModel = null;
		for (Element actionEle : actionEleList) {
			 actionModel = new ActionModel();
			actionModel.setPath(actionEle.attributeValue("path"));
			actionModel.setType(actionEle.attributeValue("type"));
			List<Element> forwordEleList = actionEle.selectNodes("forward");
			for (Element forwordEle : forwordEleList) {
				forwardModel = new ForwardModel();
				forwardModel.setName(forwordEle.attributeValue("name"));
				forwardModel.setPath(forwordEle.attributeValue("path"));
				forwardModel.setRedirect(forwordEle.attributeValue("redirect"));
				actionModel.put(forwardModel);
			}

			configModel.put(actionModel);
		}

		return configModel;
	}
	
	public static void main(String[] args) {
		try {
			ConfigModel configModel = ConfigModelFactory.newInstance();
			ActionModel actionModel = configModel.get("/loginAction");
			ForwardModel forwardModel = actionModel.get("failed");
			System.out.println(actionModel.getType());
			System.out.println(forwardModel.getPath());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

（4）ForwardModel

package com.az.framework;

import java.io.Serializable;

/**
 * 鐢ㄦ潵鎻忚堪forward鏍囩
 * @author Administrator
 *
 */
public class ForwardModel implements Serializable {

	private static final long serialVersionUID = -8587690587750366756L;

	private String name;
	private String path;
	private String redirect;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPath() {
		return path;
	}

	public void setPath(String path) {
		this.path = path;
	}

	public String getRedirect() {
		return redirect;
	}

	public void setRedirect(String redirect) {
		this.redirect = redirect;
	}

}

DispatcherServlet：

package com.az.framework;

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

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

import org.apache.commons.beanutils.BeanUtils;

/**
 * 中央控制器
 * 作用：
 *    接受用户请求，通过用户请求的url寻找指定的子控制器去处理业务
 *    
 * 1、对存放子控制器action容器的增强
 *    原来为了完成业务需求，需要不断修改框架的代码，这种设计是不合理的
 *    处理方式：参照web.xml的实际方法，来完成中央控制器管理子控制器的动态配置
 *    
 * 2、 处理结果码的跳转方式
 *    达到简化代码
 *    
 * 3、将基础操作放到一个子控制器
 *   
 *     
 * 4、处理jsp传递到后台的参数配置
 * 
 * 5、解决框架配置文件重名冲突的问题
 * 
 *    
 * @author zuo_fan
 *
 */
public class DispatcherServlet extends HttpServlet {

	private static final long serialVersionUID = -3841666976794538752L;
	
	/**
	 *  用来存放 子控制器
	 */
	
	private ConfigModel configModel = null;
	
	public void init() {
		try {
			String mvcXmlLocation = this.getInitParameter("mvcXmlLocation"); //  5.mvc 的默认地址
			if(null == mvcXmlLocation || "" .equals(mvcXmlLocation)) {
				mvcXmlLocation="/mvc.xml";
			}
			configModel =ConfigModelFactory.newInstance();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doPost(req, resp);
	}
	
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String url=req.getRequestURI();
        url=url.substring(url.lastIndexOf("/"),url.lastIndexOf("."));
       /* Action action = actionMap.get(url);*/
       ActionModel actionModel = configModel.get(url);
       
        try {
        	 // 2 2如果客户没有配置 需要提示
        	if(actionModel == null) {
        		throw new RuntimeException("您还未配置子控制器来处理用户请求"); 
        	}
        	//1  类地址 进行实例化
			Action action = (Action) Class.forName(actionModel.getType()).newInstance();
			
			//4加强
			if(action instanceof ModelDriver) {
				ModelDriver modelDriver = (ModelDriver) action;
				Object model = modelDriver.getModel();
//				给 model 赋值了,那么意味这在调用add/del不在是空值
                BeanUtils.populate(model, req.getParameterMap());
			}
			// 3加强   
			String code = action.execute(req, resp);
			ForwardModel forwardModel = actionModel.get(code);
			if("false".equals(forwardModel.getRedirect())) {
				req.getRequestDispatcher(forwardModel.getPath()).forward(req, resp);
			}else {
				// 2注意：默认会缺损项目名    req.getContextPath()
				resp.sendRedirect(req.getContextPath()+ forwardModel.getPath());
			}
			
		} catch (Exception e) {
			e.printStackTrace();
	   }
	}
}

cal.jsp主界面

<%@ 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(v){
    	if(v==1){
    		calForm.action = "${pageContext.request.contextPath}/cal.action?methodName=add";
    	}else if(v==2){
    		calForm.action = "${pageContext.request.contextPath}/cal.action?methodName=del";
    	}else if(v==3){
    		calForm.action = "${pageContext.request.contextPath}/cal.action?methodName=ride";
    	}else if(v==4){
    		calForm.action = "${pageContext.request.contextPath}/cal.action?methodName=divide";
    	}
    	calForm.submit();
    }
</script>
</head>
<body>
	<form id="calForm" action="" method="post">
		num1:<input name="num1"><br> 
		num2:<input 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>

子控制器

package com.az.framework;

import java.io.IOException;

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

/**
 * 子控制器： 
 *        作用：具体处理用户请求的类(实现Action接口类)
 * 
 * @author zuo_fan
 *
 */
public interface Action {
	String execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException;
}

ActionSupport:

package com.az.framework;

import java.io.IOException;
import java.lang.reflect.Method;

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

/**
 * 增强控制器
 *   作用: 将一组操作数组放到一个子控制器去完成
 * 
 * @author zuo_fan
 *
 */
public class ActionSupport implements Action {

	public String execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//	从前台传递需要调用的方法名到后台，实现动态方法调用   url后面加  &methodName
		String code =null;
		String methodName = req.getParameter("methodName");
        try {
			Method m = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
			m.setAccessible(true);
			// 获得方法 返回值
			code=(String) m.invoke(this, req,resp);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return code;
	}

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>az_mvc1</display-name>
  
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>com.az.framework.DispatcherSerclet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>

</web-app>

CalAction:
作用：把方法都写在一起，通过jsp前端methodName传值调用这个类中的方法

package com.az.web;

import java.io.IOException;

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

import com.az.entity.Cal;
import com.az.framework.ActionSupport;
import com.az.framework.ModelDriver;

public class CalAction extends ActionSupport implements ModelDriver<Cal>{
	
	private  Cal cal = new Cal();
	// 加
	public String add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
	    // 第4部加强 替代的代码
		/*String num1=req.getParameter("num1");
		String num2=req.getParameter("num2");
		Cal cal = new Cal(num1, num2);*/
		req.setAttribute("rs",Integer.valueOf(cal.getNum1())+Integer.valueOf(cal.getNum2()));
//		req.getRequestDispatcher("rs.jsp").forward(req, resp);
		return "rs";
	}
	// 减
	public String del(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
	
		req.setAttribute("rs",Integer.valueOf(cal.getNum1())-Integer.valueOf(cal.getNum2()));
		return "rs";
	}

	//乘
   public String ride(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {	
	   req.setAttribute("rs",Integer.valueOf(cal.getNum1())*Integer.valueOf(cal.getNum2()));
	   return "rs";
   }
   // 除
   public String divide(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {	
	   req.setAttribute("rs",Integer.valueOf(cal.getNum1())/Integer.valueOf(cal.getNum2()));
	   return "rs";
   }
	public Cal getModel() {
		return cal;
	}
}

ModelDriver 接口——模型驱动接口
作用：给对应处理业务的子控制器中包含的实体类进行jsp参数封装

package com.az.framework;

/**
 * 模型驱动接口
 *  作用：给对应处理业务的子控制器中包含的实体类进行jsp参数封装
 * @author zuo_fan
 *
 */
public interface ModelDriver<T> {
	 T getModel();
}

rs.jsp结果显示

<%@ 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>
结果：${rs}
</body>
</html>

加法运算显示
在这里插入图片描述

在这里插入图片描述

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