actionprocessor.java~

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/*

 */
package com.sun.j2ee.workflow.control.web;

import java.util.Collection;
import java.util.HashMap;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.*;

import java.rmi.RemoteException;
import com.sun.j2ee.workflow.util.Debug;
import com.sun.j2ee.workflow.util.WebKeys;
import com.sun.j2ee.workflow.control.exceptions.StarsEventException;
import com.sun.j2ee.workflow.control.web.ScreenFlowManager;

import com.sun.j2ee.workflow.control.web.actions.RequestHandler;


/**
 *
 */
public class RequestProcessor implements java.io.Serializable {

    private ServletContext context;
    private HashMap urlMappings;

    /** Empty constructor for use by the JSP engine. */
    public RequestProcessor() {}


    public void init(ServletContext context) {
        this.context = context;
        urlMappings = (HashMap)context.getAttribute(WebKeys.URLMappingsKey);
    }

    /**
    */

    private URLMapping getURLMapping(String urlPattern) {
        if ((urlMappings != null) && urlMappings.containsKey(urlPattern)) {
            return (URLMapping)urlMappings.get(urlPattern);
        } else {
            return null;
        }
    }


    /**
    * This method is the core of the RequestProcessor. It receives all requests
    *  and generates the necessary events.
    */
    public void processRequest(HttpServletRequest request, HttpServletResponse response) throws StarsEventException, IOException {
        StarsEvent event = null;
        String selectedUrl = request.getPathInfo();
        String checkresult = null; //to check the access control
        PrintWriter out = response.getWriter();
        ModelManager mm = (ModelManager)request.getSession().getAttribute(WebKeys.ModelManagerKey);
        // application level ModelManager 
        AppModelManager apmm = (AppModelManager)context.getAttribute(WebKeys.AppModelManagerKey);
        // application level checkermanager
        CheckerManager chm = (CheckerManager)context.getAttribute(WebKeys.CheckerManagerKey);
        UserHandlerWebImpl ucrwimpl = (UserHandlerWebImpl)request.getSession().getAttribute(WebKeys.WebHandlerKey);
        if (ucrwimpl == null) {
            ucrwimpl = new UserHandlerWebImpl(request.getSession());
            mm.setURC(ucrwimpl);
            request.getSession().setAttribute(WebKeys.WebHandlerKey, ucrwimpl);
        }
       RequestHandler handler = getHandler(selectedUrl);
       if (handler != null) {
           handler.setServletContext(context);
           handler.doStart(request);
           event = handler.processRequest(request);
           //check the consistency for this even
           
           if (event != null) {
               
                   checkresult = chm.checkEvent(event);
                   if(checkresult.equals("OK"))
                   {
                       chm.doStart(event); //update model state
                       Collection updatedModelList = ucrwimpl.handleEvent(event);
                       mm.notifyListeners(updatedModelList);
                       apmm.notifyListeners(updatedModelList);
                       chm.doEnd(event); //reset model state
                   }
                   out.println(checkresult);
           }
           handler.doEnd(request);
        }
       out.close();
    }

    /**
     * This method load the necessary RequestHandler class necessary to process a the
     * request for the specified URL.
     */

    private RequestHandler getHandler(String selectedUrl) {
        RequestHandler handler = null;
        URLMapping urlMapping = getURLMapping(selectedUrl);
        String requestProcessorString = null;
        if (urlMapping != null) {
            requestProcessorString = urlMapping.getRequestHandler();
            if (urlMapping.useRequestHandler()) {
                try {
                    Debug.println("RequestProcessor: loading handler " + requestProcessorString);
                    handler = (RequestHandler)getClass().getClassLoader().loadClass(requestProcessorString).newInstance();
                    Debug.println("RequestProcessor: loaded handler " + requestProcessorString);
                } catch (Exception ex) {
                   Debug.println("RequestProcessor caught loading handler: " + ex);
                }
            }
        }
        return handler;
    }

}