[CentOS-docs] Suggestion for "how to" section: easy way to install the JDK?
wolfy at nobugconsulting.ro
Sat Oct 9 03:32:19 EDT 2010
On 10/09/2010 04:33 AM, Milos Blazevic wrote:
> Bob Stine wrote:
>> Milos Blazivec wrote:
>> /... I am, in fact, interested in making adjustments to the Wiki /
>> /page - but sadly not the ones you proposed Bob, since the just
>> won't do /
>> /the trick./
>> Hmm. I ran the executed the bin file, edited /etc/profile so that
>> PATH included the "bin" directory of the sun jdk directory, added
>> environment variable JDK_HOME, deleted the /usr/bin/java symlink from
>> java -> /etc/alternative/java, and everything works, or at least well
>> enough for me to run the Eclipse C++ IDE, which was my goal.
>> Maybe adding the jdk was unnecessary for Eclipse to work?
>> Could you unpack "just won't do", or point to a discussion of the issue?
> What I meant is that the instructions you suggested in your first e-mail
> are taken from:
> and are all but comprehenssive, let alone appropriate for beginners.
> These installation instructions have been accompanying Sun Java as long
> as I can remember, and "strangely", no one cared to mention 'em in the
> Wiki page... don't you think that's kinda odd? I don't - 'cause they
> don't work!
> This second part (editing /etc/profiles, deleting symlinks and editing
> PATH...) is NOT what you mentioned in your first e-mail. However, in my
> honest oppinion, this is still not the correct way to do this.
> What you did, is that you probably got it to work for Your particular
> purpose by resorting to an unconventional method (i.e. circumvent the
> mechanism intended for this purpose, rather than a by-the-book
> approach). By solving the problem this way, sooner or later you'll end
> up breaking something. Maintainance may prove difficult later
> For me, by-the-book is using "alternatives" utility for this purpose -
> intended by the makers way to handle this kind of issues. (switching
> between different mail servers, etc.)
Using alternatives in the context of Java is 100% useless for ordinary
users who do not want to use the stock gcj or openjdk packages ( and
therefore replace them with Sun's packages). As far as I have seen on
the few hundreds workstations that I maintain + the requests in the IRC
channel, users only need to run
- browser java plugin ( solved by installing Sun's jre + a convenient
ln -s already mentioned before in this thread
- java ( the binary, as in " java -Xmx400m -DuseDesktop=true
-Dsun.java2d.pmoffscreen=false -jar /usr/share/jalbum/JAlbum.jar ") in
order to run .jar applications
- the libs needed by Eclipse, also mentioned before in the thread
> Better idea is to adjust symlink to point to the desired binary, rather
> than editing PATH variable, deleting the symlink,...
At least the jre package (and I am almost sure jdk too) from Sun comes
with the following structure:
lrwxrwxrwx 1 root root 16 Apr 10 01:25 default -> /usr/java/latest
drwxr-xr-x 7 root root 4096 Jun 28 23:34 jre1.6.0_20
lrwxrwxrwx 1 root root 21 Jun 28 23:35 latest -> /usr/java/jre1.6.0_20
Using /usr/java/latest and / or /usr/java/default in your scripts makes
them immune to upgrades, as long as you stick with Sun's packages (
which - sad but true - make the java-openjdk / gcj packages useless and
offer ( for the moment ) better compatibility with the real world. At
least from I where I stand.
More information about the CentOS-docs