MVC的核心控制器

import java.io.IOException;
import javax.servlet.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import java.lang.reflect.Field;
import java.io.*;
import beans.action.*;
import java.lang.reflect.*;
/**
*
* @author Semor
*
*/
public class Controller extends HttpServlet {
    private static final long serialVersionUID = 1L;   
      
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Controller() {       
        super();
        //
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doPost(request,response);
    }
    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        try{           
            String configfile=this.getInitParameter("config");                   
            String req_uri=request.getRequestURI();           
            String ctxPath = request.getContextPath();
            String uri = req_uri.substring(ctxPath.length()+1);
            DocumentBuilderFactory Factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder Builder = Factory.newDocumentBuilder();
            InputStream   is=getClass().getResourceAsStream(configfile);
            Document doc=Builder.parse(is);
            doc.normalize();
            Element action = doc.getElementById(uri);           
            if(action==null)
            {               
                System.out.println("Action Not Found,Please Check Your Config File!");
                response.setContentType("text/html");
                response.setCharacterEncoding("utf-8");
                PrintWriter pw=response.getWriter();
                pw.print("Server Error!Please Visit Later");   
               
            }else{               
                Object obj=setProperty(action.getAttribute("formbean"),request);
                request.setAttribute("formbean", obj);
                Class actionbean=Class.forName(action.getAttribute("class"));
                Action ActionToExe=(Action)actionbean.newInstance();
                if(ActionToExe.execute(request,response))
                {
                    response.sendRedirect(action.getAttribute("forward")); 
                }else{
                    RequestDispatcher   dispatcher   =   request.getRequestDispatcher(action.getAttribute("errorpage"));                                      
                    dispatcher.forward(request,response);  
                }
            }
        }catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    public Object setProperty(String ClassPath,HttpServletRequest req)
    {
        try{
            Class ClassName=Class.forName(ClassPath);
            Object ClassInstance=ClassName.newInstance();
            Method[] MethToExe=ClassName.getDeclaredMethods();
            for(int i=0;i<MethToExe.length;i++)
            {                               
                String MethName=MethToExe[i].getName();
                if(MethName.substring(0, 3).equals("set"))
                {                           
                    String Parameter=req.getParameter(MethName.substring(3));
                    if(Parameter==null||Parameter.trim().equals(""))
                    {
                        continue;
                    }else{
                        Object arglist[] = new Object[1];
                        arglist[0] = new String(Parameter);                       
                        MethToExe[i].invoke(ClassInstance, arglist);
                    }
                }
            }
            return ClassInstance;
        }catch(Exception e)
        {
            e.printStackTrace();
        }
        return null;       
    }
}