code: public String getHrefValue()
      {
          String result;
          if ( hrefValue == null && getArtifact() != null )
          {
              // use default value
              result = getArtifact().getFile().getName();
          }
          else
          {
              // use customized value
              result = hrefValue;
          }
          return result;
      }
docs: Returns the value that should be output for this jar in the href attribute of the
  jar resource element in the generated JNLP file. If not set explicitly, this defaults
  to the file name of the underlying artifact.
  
  @return The href attribute to be output for this jar resource in the generated JNLP file.