Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8227368

EnumSet.class serialization broken in JDK 9+

    Details

      Backports

        Description

        I recently stumbled on an exception thrown when deserializing stream produced on JDK 8 and read with JDK 11. I narrowed the problem down to serialization/deserialization of a public EnumSet.class object. There were several changes made to EnumSet in the Mercurial history of jdk repo, but I think the following two broke the serialization:

        http://hg.openjdk.java.net/jdk/jdk/rev/d0e8542ef650
        http://hg.openjdk.java.net/jdk/jdk/rev/a7e13065a7a0

        It is interesting to note that before those two changes were made, there was a chance to fix the problem reported by newly added serial lint warnings. Unfortunately they were just silenced:

        http://hg.openjdk.java.net/jdk/jdk/rev/501d8479f798

        +@SuppressWarnings("serial") // No serialVersionUID due to usage of
        + // serial proxy pattern

        It is true that serialization of instances of Serializable classes is not broken by changes to them when they implement serial proxy pattern (i.e. writeReplace() method) even if they don't itself declare a private static final long serialVersionUID field, but this is not true of Class objects representing those Serializable classes. It is even more controversial that serialization of Class objects representing non-Serializable classes is never broken, because their serialVersionUID value is always interpreted as 0 (which is understandable as they don't have a habit of declaring serialVersionUID fields).

        Both of the above breaking changes were made post JDK 8 release, so deserialization of JDK 8 (and older) streams is affected in all JDK 9 + releases or vice versa.

          Attachments

            Issue Links

              Activity

                People

                • Assignee:
                  plevart Peter Levart
                  Reporter:
                  plevart Peter Levart
                • Votes:
                  0 Vote for this issue
                  Watchers:
                  6 Start watching this issue

                  Dates

                  • Created:
                    Updated:
                    Resolved: