Examples of sunlabs.brazil.properties.PropertiesList

sunlabs.brazil.properties.PropertiesList

A PropertiesList instance is intended to be an element of a doubly linked list consisting of other PropertiesList instances. Each PropertiesList instance "wraps" a Dictionary object. A PropertiesList is a subclass of Properties and therefore provides the same API, including the methods and fields of Dictionary and Hashtable. The PropertiesList class overrides all methods of the Properties API and delegates the method evaluation to the wrapped Properties object.

The linked list of PropertiesList objects is constructed by Request for each incoming request. That is, there is a unique PropertiesList linked list for each request. The head of the initial list constructed by request is Request.props and the tail of the two element list is Request.serverProps. The former wraps an empty Properties object, while the latter wraps Server.props. Other PropertiesList objects can be added, and removed, from this initial list as required.

Given a reference to a PropertiesList object on the linked list (e.g. request.props), one typically "looks up" the value associated with a name using the getProperty method, which delegates to the wrapped Properties.getProperty method. If the result is null, meaning the name/value pair is not stored in the wrapped Properties object, the request is "forwarded" to the next object on the linked list, and so on until either the name/value pair is found (and the value is returned) or the end of the list is reached (and null is returned).

It may be desirable for the name/value lookup to be delayed until after the lookup request has been passed on to subsequent objects on the list. This can be done by using the two parameter constructor and setting the second, boolean, parameter to true. Then the getProperty request is forwarded to the next object in the list rather than delegated to the wrapped Properties object. If the result of the forwarded request is null, the request is then passed to the wrapped Properties object and it's result is returned. @author Steve Drach <drach@sun.com> @version 2.7 @see java.util.Dictionary @see java.util.Hashtable @see java.util.Properties

  }


  /*
         * Delay initialization until we know we need these things
         */
  serverProps = new PropertiesList(server.props);
  props = new PropertiesList();
  props.addBefore(serverProps);
  props.put("url.servlet", origUrl);


  return true;
    }

  }


  /*
         * Delay initialization until we know we need these things
         */
  serverProps = new PropertiesList(server.props);
  props = new PropertiesList();
  props.addBefore(serverProps);


  /*
   * Keep track of the original url.  This is backwards (for
   * historical reasons

    System.out.println("addSharedProps didn't add dict"
         + Integer.toHexString(System.identityHashCode(d)));
      }
      return false;
  }
  PropertiesList pl = new PropertiesList(d);
  pl.addAfter(props);
  if (debug) {
      props.dump(true, "at addSharedProps");
  }
  return true;
    }

     *    added).
     */
    public boolean
    removeSharedProps(Dictionary d)
    {
  PropertiesList pl = props.wraps(d);
  if (pl != null && pl != props && pl != serverProps) {
      pl.remove();
      if (server.props.get("debugProps") != null) {
    pl.dump(true, "at removeSharedProps");
      }
      return true;
  }
  return false;
    }

Examples of sunlabs.brazil.properties.PropertiesList

Related Classes of sunlabs.brazil.properties.PropertiesList