Resource.java

/**
 * This file is part of OCPsoft SocialPM: Agile Project Management Tools (SocialPM) 
 *
 * Copyright (c)2011 Lincoln Baxter, III <lincoln@ocpsoft.com> (OCPsoft)
 * Copyright (c)2011 OCPsoft.com (http://ocpsoft.com)
 * 
 * If you are developing and distributing open source applications under 
 * the GNU General Public License (GPL), then you are free to re-distribute SocialPM 
 * under the terms of the GPL, as follows:
 *
 * SocialPM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * SocialPM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with SocialPM.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * For individuals or entities who wish to use SocialPM privately, or
 * internally, the following terms do not apply:
 *  
 * For OEMs, ISVs, and VARs who wish to distribute SocialPM with their 
 * products, or host their product online, OCPsoft provides flexible 
 * OEM commercial licenses.
 * 
 * Optionally, Customers may choose a Commercial License. For additional 
 * details, contact an OCPsoft representative (sales@ocpsoft.com)
 */
package com.ocpsoft.socialpm.rewrite;

import java.net.MalformedURLException;

import com.ocpsoft.logging.Logger;
import com.ocpsoft.rewrite.bind.Evaluation;
import com.ocpsoft.rewrite.bind.ParameterizedPattern;
import com.ocpsoft.rewrite.context.EvaluationContext;
import com.ocpsoft.rewrite.param.Parameter;
import com.ocpsoft.rewrite.servlet.config.HttpCondition;
import com.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;

/**
 * @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
 */
public class Resource extends HttpCondition
{
   // TODO move to rewrite proper
   private static final Logger log = Logger.getLogger(Resource.class);

   private ParameterizedPattern resource = new ParameterizedPattern("/pages/{page}.xhtml");

   private Resource(final String resource)
   {
      this.resource = new ParameterizedPattern(resource);

      for (Parameter<String> parameter : this.resource.getParameters().values()) {
         parameter.bindsTo(Evaluation.property(parameter.getName()));
      }
   }

   @Override
   public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
   {
      String file = resource.build(event, context);
      try {
         return event.getRequest().getServletContext().getResource(file) != null;
      }
      catch (MalformedURLException e) {
         log.debug("Invalid file format [{}]", file);
      }
      return false;
   }

   public static Resource exists(final String resource)
   {
      return new Resource(resource);
   }
}