actioncomponentservlet.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

/*
 * $Header: /sfroot/cvs/esimple/src/core/org/apache/struts/tiles/ActionComponentServlet.java,v 1.1.1.1 2004/09/08 06:38:35 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:35 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Struts", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
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 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.struts.tiles;

import java.io.IOException;

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

import org.apache.struts.Globals;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.taglib.html.Constants;
import org.apache.struts.upload.MultipartRequestWrapper;

/**
 * Action Servlet to be used with Tiles and Struts 1.0.x.
 * For Struts 1.1, use TilesPlugin and eventualy TilesRequestProcessor.
 * This servlet extends struts one. It adds channels and screens dispatching
 * capabilities.
 * We overide all methods that do request forward (i.e. 'processActionForward'
 * and 'processValidate') in order to call a new method performing forward.
 * In fact, we copy  methods to overide, and change lines doing forward which
 * now call 'processForward()'. Rest of the method is unchanged.
 * This new method could now be overiden in order to dispatch request before
 * forwarding.
 * Compliant to ActionServlet from struts 2001/06/25 00:02:27
 * @deprecated Tiles now uses ActionServlet with TilesPlugin and TilesRequestProcessor.
 */
public class ActionComponentServlet extends ActionServlet {
      /** Definitions factory */
    private DefinitionsFactory definitionsFactory;

    /**
     * Init method.
     * This method is call on any servlet.
     */
  public void init() throws ServletException
  {
  super.init();
  initComponentDefinitionsMapping();
  }

    /**
     * Read component instance mapping configuration file.
     * This is where we read files properties.
     */
  public void initComponentDefinitionsMapping() throws ServletException // IOException,
  {
    // Check struts version by checkin PlugIn classes existance.
  try
    {
    Class plugInClass = TilesUtil.applicationClass( "org.apache.struts.action.PlugIn");
      // Class exist ==> struts 1.1 or greater
    log( "Warning - ActionComponentServlet class: This class is to be used with Struts1.0.x only. "
            + "Please modify web.xml to use regular ActionServlet class instead in conjugaison "
            + "with appropriate plugin declared in struts-config.xml.");
    //return;
    // Let create factory for backward compatibility
    }
   catch( ClassNotFoundException ex )
    { // Not found ==> struts 1.0.x
    }

  try
    {
         // create definition factory
    definitionsFactory = DefinitionsUtil.createDefinitionsFactory(getServletContext(), getServletConfig(), true);
    }
   catch( DefinitionsFactoryException ex )
    {
    log( "Fail to load Tiles definition factory from ActionComponentServlet", ex);
    throw new ServletException( ex.getMessage(), ex );
    }
  log("Tiles definition factory loaded from ActionComponentServlet");
  }

    /**
     * Overload struts1.0 counterpart in order to catch forward calls.
     * This is an exact copy, except the call to RequestDispatcher.forward()
     * replaced by doForward().
     * This method is only used with Struts1.0.x
     *
     * Forward to the specified destination, by the specified mechanism,
     * if an <code>ActionForward</code> instance was returned by the
     * <code>Action</code>.
     *
     * @param forward The ActionForward returned by our action
     * @param mapping The ActionMapping we are processing
     * @param formInstance The ActionForm we are processing
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet exception occurs
     */
  protected void processActionForward( ActionForward forward,
                                       ActionMapping mapping,
                                       ActionForm formInstance,
                                       HttpServletRequest request,
                                       HttpServletResponse response)
        throws IOException, ServletException
  {

  if (forward != null)
    {
    String path = forward.getPath();
    if (forward.getRedirect())
      {
      if (path.startsWith("/"))
          path = request.getContextPath() + path;
      response.sendRedirect(response.encodeRedirectURL(path));
      }
     else
      {
      doForward(path, request, response);
      }
    }

  }

    /**
     * Overload struts1.0 counterpart in order to catch forward calls.
     * This is an exact copy, except the call to RequestDispatcher.forward()
     * replaced by doForward().
     * This method is only used with Struts1.0.x
     *
     * Call the <code>validate()</code> method of the specified ActionForm,
     * and forward back to the input form if there are any errors.  Return
     * <code>true</code> if we should continue processing (and call the
     * <code>Action</code> class <code>perform()</code> method), or return
     * <code>false</code> if we have already forwarded control back to the
     * input form.
     *
     * @param mapping The ActionMapping we are processing
     * @param formInstance The ActionForm we are processing
     * @param request The servlet request we are processing
     * @param response The servlet response we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet exception occurs
     */
    protected boolean processValidate(ActionMapping mapping,
        ActionForm formInstance, HttpServletRequest request,
        HttpServletResponse response)
        throws IOException, ServletException {

        if (formInstance == null)
            return (true);
        if (debug >= 1)
            log(" Validating input form properties");

        // Was this submit cancelled?
        if ((request.getParameter(Constants.CANCEL_PROPERTY) != null)
            || (request.getParameter(Constants.CANCEL_PROPERTY_X) != null)) {
            if (debug >= 1)
                log("  Cancelled transaction, no validation");
            return (true);
        }

        // Has validation been turned off on this mapping?
        if (!mapping.getValidate())
            return (true);

        // Call the validate() method of our ActionForm bean
        // Use struts1.0 compatible method, as this class is mainly for struts1.0
        // backward compatibility.