Function does not implement Serializable

[GoogleCodeExporter]

Hi all,

When you perform Lists.transform and pass a Function the result is a 
TransformingRandomAccessList that indeed is Serializable, but Function is also 
a member of this class and Function is not Serializable which makes the whole 
object not Serializable as well.

Is this a known issue?

Original issue reported on code.google.com by rpvi...@gmail.com on 23 May 2013 at 2:24

[GoogleCodeExporter]

The solution here is to make your Function Serializable, since not all 
Functions are (or should be!) Serializable.  (This may require an explicit 
named class, rather than an anonymous class, of course.)

Original comment by wasserman.louis on 24 May 2013 at 6:17

[GoogleCodeExporter]

Hello,

Thank you for your comment. I just have a question... why isn't the function 
Serializable? 99% of the people using this library use an anonymous function 
and without any members, right? Am I missing something here?

From a user perspective I never expected that the function would be even stored 
in a member! What could be the harm in extending Serializable in the Function 
interface?

Cheers!

--
Rui

Original comment by rpvi...@gmail.com on 24 May 2013 at 9:00

[GoogleCodeExporter]

Never make abstract types Serializable! Serialization is fundamentally an 
implementation concern; each implementation needs to decide whether it wants to 
be serializable, and if it does, _how_ it wants to be serializable (you cannot 
assume that default serialization is right for each case). If we make our 
interfaces serializable we can open security holes, not to mention that users 
who have all their javac warnings enabled will get a serialVersionUID warning 
on every single function in their entire codebase, which would be horrible.

If you find any actual *Functions* in our codebase that we return to you but 
did not make serializable, please report those.

In Java 8, serializable functions will be as easy as "transform((& 
Serializable) a -> a.b())".  (Or at least I think that proposal carried... hmm.)

Original comment by kevinb@google.com on 24 May 2013 at 2:24

• Changed title: Function does not implement Serializable
• Changed state: WorkingAsIntended

[GoogleCodeExporter]

Fair enough :)

Original comment by rpvi...@gmail.com on 24 May 2013 at 2:26

[GoogleCodeExporter]

This issue has been migrated to GitHub.

It can be found at https://github.com/google/guava/issues/<issue id>

Original comment by cgdecker@google.com on 1 Nov 2014 at 4:12

• Added labels: MigratedToGitHub

[GoogleCodeExporter]

Original comment by cgdecker@google.com on 3 Nov 2014 at 9:08

• Added labels: Restrict-AddIssueComment-Commit