code: public void addActionOutput( String paramName, Object value )
      {
          if ( paramName == null || paramName.length() == 0 )
          {
              throw new IllegalArgumentException( "An action output name may not be null or empty." );
          }
          
          if ( _actionOutputs == null )
          {
              _actionOutputs = new HashMap();
          }
          
          //
          // Throw an exception if this is a redirect, and if there was an action output.  Action outputs are carried
          // in the request, and will be lost on redirects.
          //
          if ( _init && getRedirect() )
          {
              String actionPath = _mappingPath != null ? _mappingPath : "";
              String descrip = getName() != null ? getName() : getPath();
              PageFlowException ex = new IllegalActionOutputException( descrip, actionPath, _flowController, paramName );
              InternalUtils.throwPageFlowException( ex );
          }
          
          _actionOutputs.put( paramName, value );
      }
docs: Adds an action output that will be made available in the request, through {@link PageFlowUtils#getActionOutput}.
  
  @param paramName the name of the action output.
  @param value the action output value.