String charSet = this.mediaType.getParameterValue("charset");
String charSet = this.mediaType.getParameters().getFirstValue("charset");
   public ContentType(String headerValue)   {      try      {         PreferenceReader pr = new PreferenceReader(PreferenceReader.TYPE_MEDIA_TYPE, headerValue);         Preference pref;         pref = pr.readPreference();         this.mediaType = (MediaType)pref.getMetadata();         String charSet = this.mediaType.getParameterValue("charset");         if(charSet != null)         {            this.characterSet = new CharacterSet(charSet);         }      }      catch(IOException ioe)      {         ioe.printStackTrace();      }   }