prefixactionfactoryproxy.java

webwork source

/*
 * WebWork, Web Application Framework
 *
 * Distributable under Apache license.
 * See terms of license at opensource.org
 */
package webwork.action.factory;

import org.apache.commons.logging.*;
import webwork.action.Action;
import webwork.config.Configuration;

import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Map;
import java.util.StringTokenizer;

/**
 * Locate an action based on the configured list of package prefixes.
 * The configuration property <code>webwork.action.packages</code> is used
 * to specify a comma separated list of packages that should be considered
 * as prefixes.  The default package prefix list is: <code>webwork.action.test</code>
 * and <code>webwork.action.standard</code>.
 *
 * @author Rickard 謆erg ([e-mail])
 * @version $Revision: 1.17 $
 */
public class PrefixActionFactoryProxy
   extends ActionFactoryProxy
{
   // Attributes ----------------------------------------------------
   static String actionPrefix ="webwork.action.test,webwork.action.standard";
   String[] actionPrefixes;

   Map actionNames = new Hashtable();

   // Constructors --------------------------------------------------
   public PrefixActionFactoryProxy(ActionFactory aFactory)
   {
      super(aFactory);

      // Get list of prefixes to try
      try
      {
         actionPrefix += ","+(Configuration.getString("webwork.action.packages")).trim();
      } catch (IllegalArgumentException e)
      {
         LogFactory.getLog(this.getClass()).info("Error loading action prefixes. Only using default prefixes:"+actionPrefix);
      }

      StringTokenizer tokens = new StringTokenizer(actionPrefix, ", ");
      ArrayList prefixes = new ArrayList();
      while (tokens.hasMoreTokens())
      {
         prefixes.add(tokens.nextToken());
      }
      actionPrefixes = new String[prefixes.size()];
      //Category.getInstance(this.getClass()).debug(prefixes.toString());
      prefixes.toArray(actionPrefixes);
   }

   // ActionFactory overrides ---------------------------------------
  /**
   * Returns an action class instance after searching through a list of
   * package prefixes from the configuration properties.  If no action
   * was found, get the action from the action factory proxy chain.
   *
   * @param   aName
   * @return   action whose name may be prefixed by this factory
   * @exception   Exception
   */
   public Action getActionImpl(String aName)
     throws Exception
   {
      // Check cache
      String actionName = (String)actionNames.get(aName);

      // Find class
      if (actionName == null)
      {
         Action action = null;
         for (int i = 0; i < actionPrefixes.length; i++)
         {
            try
            {
               action = getNextFactory().getActionImpl(actionPrefixes[i] + "."+aName);
               if(action != null)
               {
                 // Put in cache
                 actionNames.put(aName, actionPrefixes[i] + "."+aName);
                 break;
               }
            } catch (Exception e)
            {
               // Not found with this prefix
            }
         }

         // Try without prefix
         if (action == null)
         {
            action = getNextFactory().getActionImpl(aName);
            // Put in cache
            actionNames.put(aName, aName);
         }

         // Return the action
         return action;
      } else
      {
         return getNextFactory().getActionImpl(actionName);
      }
   }

   public void flushCaches() {
      getNextFactory().flushCaches();
      actionNames.clear();
   }
}