一个简单的MVC框架的实现

Posted 2020-06-16

1、Action接口 

package com.togogo.webtoservice;

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

public interface Action {
    
    /**
     * 默认的执行方法
     * @param request 传入处理的请求对象
     * @param response 传入处理的响应对象
     * @return 返回一个跳转的路径
     */
    public String execute(HttpServletRequest request,
            HttpServletResponse response);

}

 

2、BaseAction的父类

package com.togogo.webtoservice;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

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

public abstract class BaseAction implements Action {

    @Override
    public String execute(HttpServletRequest request,
            HttpServletResponse response) {
        String result = null;
        String uri = request.getRequestURI();
        StringBuilder sb = new StringBuilder(uri);
        String path = sb.substring(uri.lastIndexOf("!") + 1,
                uri.lastIndexOf("."));
        // 已知，方法与uri的参数的字符串，一样的，那么有没有方法，可以通过方法名（字符串）直接调用方法？
        // 实现通过方法名，直接调用方法，就类动态技术
        try {
            Method method = this.getClass().getDeclaredMethod(path,
                    HttpServletRequest.class, HttpServletResponse.class);
            result = (String) method.invoke(this, request, response);
        } catch (NoSuchMethodException e) {
            
            e.printStackTrace();
        } catch (SecurityException e) {
         
            e.printStackTrace();
        } catch (IllegalAccessException e) {
     
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            
            e.printStackTrace();
        } catch (InvocationTargetException e) {
   
            e.printStackTrace();
        }

        return result;
    }

}

 

3、配置类

package com.togogo.webtoservice;

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

/**
 * 路径与类名映身
 * 
 * @author Administrator
 *
 */
public class Config {
    // private static Map<String, String> classNames = new HashMap<String,
    // String>();

    /**
     * 通过key
     * 
     * @param key
     * @return
     */
    public static String getClassName(String key, String config) {
        ResourceBundle bundle = null;
        if (config == null||"".equals(config)) {
            bundle = ResourceBundle.getBundle("Action");
        } else {
            bundle = ResourceBundle.getBundle(config);
        }
        return bundle.getString(key);
    }

    // static {
    // classNames.put("/user", "com.togogo.action.UserAction");
    // classNames.put("/admin", "com.togogo.action.AdminAction");
    // }

    public static void main(String[] args) {
        // 用于以类的形式来读取properties对象
        ResourceBundle bundle = ResourceBundle
                .getBundle("com.togogo.webtoservice.Action");
        System.out.println(bundle.getString("user"));
    }

}

 

4、DispacherServlet 类

package com.togogo.webtoservice;

import java.io.IOException;

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

public class DispacherServlet extends HttpServlet {
    private static String config=null;
    private static String enconding="UTF-8";

    @Override
    public void init(ServletConfig config) throws ServletException {
        String initConfig=config.getInitParameter("config");
        String initEnconding=config.getInitParameter("enconding");
        if(initConfig!=null){
            DispacherServlet.config=initConfig;
        }
        //通过web描述符文件web.xml配置
        if(initEnconding!=null){
            DispacherServlet.enconding=initEnconding;
        }
        
        super.init(config);
    }

    /**
     * 接收任何请求,
     */
    @Override
    protected void service(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        try {
            request.setCharacterEncoding(enconding);
            response.setCharacterEncoding(enconding);
            String uri = request.getRequestURI();
            StringBuilder sb = new StringBuilder(uri);
            String path = sb.substring(uri.lastIndexOf("/") + 1,
                    uri.lastIndexOf("!"));
            System.out.println(path);
            String className = Config.getClassName(path,config);
            Action action = ActionFactory.create(className);
            String result = action.execute(request, response);
            
            if (result.contains(":")) {
                StringBuilder resultStr = new StringBuilder(result);
                String rePath=resultStr.substring(result.indexOf(":")+1, result.length());
                if(result.contains("redirect:")){
                    response.sendRedirect(rePath);
                }else if(result.contains("forward:")){
                    request.getRequestDispatcher(rePath).forward(request, response);
                }
                
            } else {
                request.getRequestDispatcher(result).forward(request, response);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}

 

5、Action工厂类

package com.togogo.webtoservice;
public class Factory {
 
public static Action create(String className) {
Action action = null;
try {
action = (Action) Class.forName(className).newInstance();
} catch (ClassNotFoundException e) {
 
e.printStackTrace();
} catch (InstantiationException e) {
 
e.printStackTrace();
} catch (IllegalAccessException e) {
 
e.printStackTrace();
}
return action;
}
}

 

 

6、测试TestAction类

package com.togogo.action;

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

import com.togogo.webtoservice.BaseAction;

public class UserAction extends BaseAction {


    /**
     * 用户登录
     * 
     * @param request
     * @param response
     * @return
     */
    public String login(HttpServletRequest request, HttpServletResponse response) {
        System.out.println("我在登录");
       
        System.out.println("我在------登录..");
        return "main.jsp";
    }

    /**
     * 用户注册
     * 
     * @param request
     * @param response
     * @return
     */
    public String register(HttpServletRequest request,
            HttpServletResponse response) {
        System.out.println("我在注册");
        return "forward:main.jsp";
    }
    
    /**
     * 用户注册
     * 
     * @param request
     * @param response
     * @return
     */
    public String undo(HttpServletRequest request,
            HttpServletResponse response) {
        System.out.println("我在撤消");
        return "redirect:main.jsp";
    }

}

 

Action.properties映射文件

user=com.togogo.action.UserAction

web.xml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"
	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>web_mvc_webtoservice</display-name>
   <!-- 这是一个核心控制器 -->
	<servlet>
		<servlet-name>dispacherServlet</servlet-name>
		<servlet-class>com.togogo.webtoservice.DispacherServlet</servlet-class>
		<init-param>
		  <param-name>config</param-name>
		  <param-value>com.togogo.action.Action</param-value>
		</init-param>
	</servlet>

	<servlet-mapping>
		<servlet-name>dispacherServlet</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>
	
	<welcome-file-list>
		<welcome-file>default.jsp</welcome-file>
	</welcome-file-list>
</web-app>

　　

 

测试页面

<%@ 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>
</head>
<body>
<a></a>
  <form action="${pageContext.request.contextPath }/user!register.do" method="post">
<!--      <input name="clasName" value="com.togogo.action.UserAction"> -->
     <input type="submit">
  
  </form>
</body>
</html>

 

 源码下载：

http://files.cnblogs.com/files/zhuyuejiu/web_mvc_webtoserive.zip