gistfile1.java

  protected Class<? extends AvroSerializer> findSerializer(Class<?> type) {
        if (type.isAnnotationPresent(AvroUseSerializer.class))
            return type.getAnnotation(AvroUseSerializer.class).value();
        return null;
    }
// Later on
  Class<? extends AvroSerializer> serializerClazz;
        if ((serializerClazz = findSerializer(type)) != null) {
            try {
                @SuppressWarnings("unchecked")
                AvroSerializer<Object> serializer = serializerClazz.newInstance();
                DatumWriter<Object> writer = new GenericDatumWriter<Object>();
                serializer.serialize(o, writer, entityStream);

            } catch (Exception e) {
                throw new IOException(e);
            }
        }