[javaee-spec users] Consolidation of Type Conversion

From: John D. Ament <>
Date: Wed, 6 Aug 2014 22:58:05 -0400

Hi all,

So in the last few days, i've pulled out what I would consider to be the
last of my short hair dealing with type conversion in Java EE 7. In my
project, I'm using JPA 2.1, JAX-RS 2.0 and WebSockets 1.0. In my use case,
I have some POJOs that I pass around those three layers via JSON. In each
of these, I have to worry about the type conversion requirements of each of
them, specifically

JPA leverages an AttributeConverter
WebSockets use Encoder/Decoder's
JAX-RS uses MessageBodyReader/Writer

In two of these, it gets a little more confusing as I have to implement
different interfaces for reading and writing. In total I need to implement
5 different interfaces, some of which support CDI injection and others that
do not.

In addition, if you look across the Java EE spectrum, we have additional
ways in which type conversion is supported.

JMS 2.0 added support for implicit body reading when getting a message and
new ways to create messages from some POJOs.
- We did not add support a serialization process other than reconfirming
that ObjectMessage requires a Serializable object.

JSF has a Converter interface

I'm sure there are other use cases as well. I'd like to propose that the
entire platform needs to consolidate down to a single way of converting
objects, arbitrarily. Then allow each of these specs to build from that
conversion going forward.

I'm not sure the right course of action. Should this become a ticket for
this spec? Does something like this require an enhancement specification by