jackson

private class CustomValueSerializer extends StdSerializer<WebTemplateResource> {
   private final String url;

   public CustomValueSerializer(String url) {
      super(WebTemplateResource.class);
      this.url = url;
   }

   @Override
   public void serialize(WebTemplateResource res, JsonGenerator jgen, SerializerProvider serializerProvider) throws IOException {

      jgen.writeStartObject();
      Field[] fields = res.getClass().getDeclaredFields();
      jgen.writeObjectField("htmlUrl", url);

      for (Field field : fields) {
         try {