commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From craig...@apache.org
Subject cvs commit: jakarta-commons-sandbox/chain/src/java/org/apache/commons/chain/web/servlet ChainProcessor.java
Date Fri, 10 Oct 2003 03:55:51 GMT
craigmcc    2003/10/09 20:55:51

  Added:       chain/src/java/org/apache/commons/chain/web/servlet
                        ChainProcessor.java
  Log:
  Add a simple servlet that lets you dispatch incoming requests to an
  appropriate chain.  Three sample mapping commands (by path info,
  extension matching, or a named request parameter) were checked in earlier.
  
  Revision  Changes    Path
  1.1                  jakarta-commons-sandbox/chain/src/java/org/apache/commons/chain/web/servlet/ChainProcessor.java
  
  Index: ChainProcessor.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons-sandbox/chain/src/java/org/apache/commons/chain/web/servlet/ChainProcessor.java,v
1.1 2003/10/10 03:55:51 craigmcc Exp $
   * $Revision: 1.1 $
   * $Date: 2003/10/10 03:55:51 $
   *
   * ====================================================================
   *
   * 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", "Commons", 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 apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * 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.commons.chain.web.servlet;
  
  
  import java.io.IOException;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import org.apache.commons.chain.Catalog;
  import org.apache.commons.chain.Command;
  import org.apache.commons.chain.Context;
  import org.apache.commons.chain.web.ChainServlet;
  
  
  /**
   * <p>Custom subclass of {@link ChainServlet} that also dispatches incoming
   * requests to a configurable {@link Command} loaded from the configured
   * {@link Catalog}.</p>
   *
   * <p>In addition to the <em>servlet</em> init parameters supported by
   * {@link ChainServlet}, this class supports the following additional
   * parameters:</p>
   * <ul>
   * <li><strong>org.apache.commons.chain.COMMAND</strong> - Name of the
   *     {@link Command} (looked up in our configured {@link Catalog} used
   *     to process all incoming servlet requests.  If not specified,
   *     defaults to <code>command</code>.</li>
   * </ul>
   *
   * <p>Also, the <code>org.apache.commons.chain.CONFIG_ATTR</code>
   * init parameter is also used to identify the {@link Context} attribute under
   * which our configured {@link Catalog} will be made available to
   * {@link Command}s processing our requests, in addition to its definition
   * of the <code>ServletContext</code> attribute key under which the
   * {@link Catalog} is available.</p>
   */
  
  public class ChainProcessor extends ChainServlet {
  
  
      // ------------------------------------------------------ Manifest Constants
  
  
      /**
       * <p>The name of the servlet init parameter containing the name of the
       * {@link Command} (loaded from our configured {@link Catalog} to use
       * for processing each incoming request.</p>
       */
      public static final String COMMAND =
          "org.apache.commons.chain.COMMAND";
  
  
      /**
       * <p>The default command name.</p>
       */
      private static final String COMMAND_DEFAULT = "command";
  
  
      // ------------------------------------------------------ Instance Variables
  
  
      /**
       * <p>The name of the context attribute under which our {@link Catalog}
       * is stored.  This value is also used as the name of the
       * context attribute under which the catalog is exposed to commands.</p>
       */
      private String attribute = null;
  
  
      /**
       * <p>The name of the {@link Command} to be executed for each incoming
       * request.</p>
       */
      private String command = null;
  
  
      // --------------------------------------------------------- Servlet Methods
  
  
      /**
       * <p>Cache the name of the command we should execute for each request.</p>
       *
       * @exception ServletException if an initialization error occurs
       */
      public void init() throws ServletException {
  
          super.init();
          attribute = getServletConfig().getInitParameter(CONFIG_ATTR);
          if (attribute == null) {
              attribute = CONFIG_ATTR_DEFAULT;
          }
          command = getServletConfig().getInitParameter(COMMAND);
          if (command == null) {
              command = COMMAND_DEFAULT;
          }
  
      }
  
  
      /**
       * <p>Configure a {@link ServletWebContext} for the current request, and
       * pass it to the <code>execute()</code> method of the specified
       * {@link Command}, loaded from our configured {@link Catalog}.</p>
       *
       * @param request The request we are processing
       * @param response The response we are creating
       *
       * @exception IOException if an input/output error occurs
       * @exception ServletException if a servlet exception occurs
       */
      public void service(HttpServletRequest request,
                          HttpServletResponse response)
          throws IOException, ServletException {
  
          ServletWebContext context =
              new ServletWebContext(getServletContext(), request, response);
          Catalog catalog =
              (Catalog) getServletContext().getAttribute(this.attribute);
          context.put(this.attribute, catalog);
          Command command = catalog.getCommand(this.command);
          try {
              command.execute(context);
          } catch (Exception e) {
              throw new ServletException(e);
          }
  
      }
  
  
  }
  
  
  

---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org


Mime
View raw message