[developers] LOGON and java

Stephan Oepen oe at ifi.uio.no
Tue Nov 25 22:31:29 CET 2014

hi joshua,

> However I can't leave these settings turned on because the repointing of
> java to $LOGONROOT/bin/java doesn't seem to be integrated with other tools
> using java on my system.

i agree that it is somewhat intrusive for the LOGON tree to put a java
binary near the front of your PATH.  out of curiosity, though, which
problems do you see from having the LOGON version of java be the
default?  is it because the LOGON binary is no longer the latest
available version?

  1 oe at mv (~/src/logon) 64 $ type -path java
  0 oe at mv (~/src/logon) 65 $ java -version
  java version "1.6.0_24"
  Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
  Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)

> So I guess my questions is a two-parter.  The
> first part is simply practical: (1) is there a way to set up LKB to work in
> emacs without messing with java settings?

currently, i fear some creativity on your part will be required, for
example prepending ‘/usr/bin/’ to your PATH after loading the LOGON
setting, or maybe just something like

  chmod 700 $LOGONROOT/bin/java

i shall try to modify the LOGON–java integration for more harmonious
co-existence of the LOGON java binary and whatever version(s) of java
are installed locally.

> The second part is for my own
> education: (2) Are there some java programs in LOGON?  If yes, I'm still
> curious why LOGON is distributing a java binary and not simply allowing
> users to run their own java.

the java application in LOGON is UTool (which can be invoked from some
MRS browsers for scope resolution or visualization of a translation
from MRS to dominance graphs), and when we integrated it (around
2005), from what i recall, (a) java was not nearly as commonly
pre-installed on systems as it may be today, and (b) UTool required a
newer version of java than was likely to be available even on systems
with an OS-provided java.

the general LOGON philosophy still is that anything beyond basic OS
utilities shall be packaged (and versioned) in interoperable versions
with the tree (hence its relative bulkiness).  but for a relatively
unimportant (in the LOGON context) binary like java, there is no need
to put that into such a prominent position on the system PATH, i.e.
the wrapper calling out to UTool should just make sure to invoke the
LOGON version of java, without any reference to the PATH environment

best wishes, oe

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