private ExternalizableMap loadMap(String extMapName, ClassLoader loader)
     throws FileNotFoundException {
   String first = null;
   String next = extMapName;
   List<String> urls = new ArrayList<String>();
   ExternalizableMap res = null;
   while (next != null) {
     // convert the plugin class name to an xml file name
     String mapFile = next.replace('.', '/') + MAP_SUFFIX;
     URL url = loader.getResource(mapFile);
     if (url != null && urls.contains(url.toString())) {
       throw new PluginException.InvalidDefinition("Plugin inheritance loop: " + next);
     }
     // load into map
     ExternalizableMap oneMap = new ExternalizableMap();
     oneMap.loadMapFromResource(mapFile, loader);
     urls.add(url.toString());
     // apply overrides one plugin at a time in inheritance chain
     processOverrides(oneMap);
     if (res == null) {
       res = oneMap;
     } else {
       for (Map.Entry ent : oneMap.entrySet()) {
         String key = (String) ent.getKey();
         Object val = ent.getValue();
         if (!res.containsKey(key)) {
           res.setMapElement(key, val);
         }
       }
     }
     if (oneMap.containsKey(KEY_PLUGIN_PARENT)) {
       next = oneMap.getString(KEY_PLUGIN_PARENT);
     } else {
       next = null;
     }
   }
   loadedFromUrls = urls;
   return res;
 }
  protected void initResultMap() throws PluginException.InvalidDefinition {
    HttpResultMap hResultMap = new HttpResultMap();
    // XXX Currently this only allows a CacheResultHandler class to
    // initialize the result map.  Instead, don't use a CacheResultMap
    // directly, use either the plugin's CacheResultHandler, if specified,
    // or a default one that wraps the CacheResultMap

    String handler_class = null;
    handler_class = definitionMap.getString(KEY_EXCEPTION_HANDLER, null);
    if (handler_class != null) {
      try {
        resultHandler = (CacheResultHandler) newAuxClass(handler_class, CacheResultHandler.class);
        resultHandler.init(hResultMap);
      } catch (Exception ex) {
        throw new PluginException.InvalidDefinition(
            mapName + " has invalid Exception handler: " + handler_class, ex);
      } catch (LinkageError le) {
        throw new PluginException.InvalidDefinition(
            mapName + " has invalid Exception handler: " + handler_class, le);
      }
    } else {
      // Expect a list of mappings from either result code or exception
      // name to CacheException name
      Collection<String> mappings = definitionMap.getCollection(KEY_EXCEPTION_LIST, null);
      if (mappings != null) {
        // add each entry
        for (String entry : mappings) {
          if (log.isDebug2()) {
            log.debug2("initMap(" + entry + ")");
          }
          String first;
          String ceName;
          try {
            List<String> pair = StringUtil.breakAt(entry, '=', 2, true, true);
            first = pair.get(0);
            ceName = pair.get(1);
          } catch (Exception ex) {
            throw new PluginException.InvalidDefinition(
                "Invalid syntax: " + entry + "in " + mapName);
          }
          Object val;

          // Value should be either a CacheException or CacheResultHandler
          // class name.
          PluginFetchEventResponse resp =
              (PluginFetchEventResponse) newAuxClass(ceName, PluginFetchEventResponse.class, null);
          if (resp instanceof CacheException) {
            val = resp.getClass();
          } else if (resp instanceof CacheResultHandler) {
            val = WrapperUtil.wrap((CacheResultHandler) resp, CacheResultHandler.class);
          } else {
            throw new PluginException.InvalidDefinition(
                "Second arg not a "
                    + "CacheException or "
                    + "CacheResultHandler class: "
                    + entry
                    + ", in "
                    + mapName);
          }
          try {
            int code = Integer.parseInt(first);
            // If parseable as an integer, it's a result code.
            hResultMap.storeMapEntry(code, val);
          } catch (NumberFormatException e) {
            try {
              Class eClass = Class.forName(first);
              // If a class name, it should be an exception class
              if (Exception.class.isAssignableFrom(eClass)) {
                hResultMap.storeMapEntry(eClass, val);
              } else {
                throw new PluginException.InvalidDefinition(
                    "First arg not an " + "Exception class: " + entry + ", in " + mapName);
              }
            } catch (Exception ex) {
              throw new PluginException.InvalidDefinition(
                  "First arg not a " + "number or class: " + entry + ", in " + mapName);
            } catch (LinkageError le) {
              throw new PluginException.InvalidDefinition("Can't load " + first, le);
            }
          }
        }
      }
    }
    resultMap = hResultMap;
  }