requestprocessor.java

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/*

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

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


import com.sun.j2ee.workflow.util.Debug;
import com.sun.j2ee.workflow.util.WebKeys;
import com.sun.j2ee.workflow.control.exceptions.WorkflowActionException;
import com.sun.j2ee.workflow.control.web.ScreenFlowManager;

import com.sun.j2ee.workflow.control.actions.ActionHandler;


/**
 * @author Jian (James) Cai
 */
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) throws WorkflowActionException, IOException {
        HashMap event = getEvent(request);
        String selectedUrl = request.getPathInfo();
        Debug.println("RequestProcessor: processRequest: " + selectedUrl);
       /* 
        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);
        }
        */
       ActionHandler handler = getHandler(selectedUrl);
       
       if (handler != null) {
           handler.setServletContext(context); //set the servlet context for handler
           handler.setServletRequest(request);
           handler.doStart();
           //try{
           handler.perform(event);
        /*   
        }
           catch (Exception ex)
           {
                   Debug.println("RequestProcessor caught handler perform(): " + ex);               
                   throw ex;                   
           }
           */
           handler.doEnd();
        }
    }
    /**
     * This method load the necessary ActionHandler class necessary to process a the
     * request for the specified URL.
     */

    private ActionHandler getHandler(String selectedUrl) {
        ActionHandler handler = null;
        URLMapping urlMapping = getURLMapping(selectedUrl);
        String requestProcessorString = null;
        if (urlMapping != null) {
            requestProcessorString = urlMapping.getActionHandler();
            if (urlMapping.useActionHandler()) {
                try {
                    //handler = (ActionHandler)getClass().getClassLoader().loadClass(requestProcessorString).newInstance();
                    handler = (ActionHandler)Class.forName(requestProcessorString).newInstance();
                    Debug.println("RequestProcessor: loaded handler " + requestProcessorString);
                } catch (Exception ex) {
                   Debug.println("RequestProcessor caught loading handler: " + ex);
                }
            }
        }
        return handler;
    }
    
    private HashMap getEvent(HttpServletRequest request)
    {
        HashMap event = new HashMap();
        String parmName = null;
        String parmValue = null;
        for (Enumeration enum = request.getParameterNames() ; enum.hasMoreElements() ;) 
        {
             parmName = (String)enum.nextElement(); 
                     Debug.println("getEvent: "+ parmName);
             parmValue = request.getParameter(parmName);
                                  Debug.println("getEvent: "+ parmValue);
             event.put(parmName, parmValue);      
        } 
        event.put("session", request.getSession());
        return event;
    }
}