[icu-design] ICU4J API: ok to not support Serializable on MessageFormat?

[Markus S. <mar...@gm...>]

Dear ICU team & users,

Moving along the MessageFormat reimplementation... it looks like the hardest
part of the "API" to be supported with a very different implementation is
the Serializable interface. The MessageFormat class does not just read and
write the message pattern string, it reads and writes whatever non-transient
fields it has; trouble is, the old data structure would take a fair bit of
convoluted code to turn into the new one.

At the same time, there seems to be no need to serialize these *Format
classes using Java Serializable, and there seems to be consensus that the
Serializable mechanism was somewhat ill-conceived and applied to too many
classes.

I would rather not spend significant amounts of code, and developement time,
on a non-trivial, questionable feature...

*Proposal*: Implement readObject() and writeObject() and just have them
throw java.io.*NotSerializable*Exception<http://download.oracle.com/javase/6/docs/api/java/io/NotSerializableException.html>.
(Yes, there is a nice, standard, JDK 1.1 Exception class for "when an
instance is required to have a Serializable interface" but we don't actually
want to implement it.)

Sincerely,
markus