[isabelle-dev] jdk-11

[Makarius]

Oracle has released Java 11 last week: it is the new long-term-support
(LTS) version for the next 3 years. Public support for Java 8 will stop
in Jan-2019.

As of Isabelle/9dabb405a3ba we are on that version by default. Due to
changes in the licensing and packaging, we are on the official OpenJDK
version provided by Oracle, see http://jdk.java.net/11 which also
provides release notes etc.

If there is a serious problem, it is still possible to switch back to
Java 8 in $ISABELLE_HOME_USER/etc/settings like this:

  init_component "$HOME/.isabelle/contrib/jdk-8u181"


Here are some pending problems:

  * Apple Desktop integration does not work:
https://sourceforge.net/p/jedit/bugs/4068

    This also means that COMMAND-Q switches the light off with a hammer:
unsaved buffers are not stored.

  * WARNING: Illegal reflective access by isabelle.Main$
(file:/home/makarius/isabelle/repos/lib/classes/Pure.jar) to field
java.util.Collections$UnmodifiableMap.m

    This was my own unofficial way to implement putenv until Java 8. It
still happens to work, but I need to find a proper way.


So many things have changed with Java 9/10/11, and more problems are to
be expected. Please report any observations in the isabelle-dev mailing
list.


	Makarius