[Sussex] vvv confused with java - jre, sdk and jvm

[John D.]

Ronan Chilvers wrote:
> Hi John
>
> On Mon, 25 Jul 2005 12:31:47 +0100
> "John D." <john at johnsemail.eclipse.co.uk> wrote:
>
>   
>> Ronan Chilvers wrote:
>>     
>>> On Mon, 25 Jul 2005 00:40:48 +0100
>>> "John D." <john at johnsemail.eclipse.co.uk> wrote:
>>>       
>
>   
>>> ;-)
>>>       
>> Ok, so I can see how that should work. I'm presuming that where Ronan 
>> says "=[whatever]" does the whatever mean something like /usr/lib/jdk 
>> 1.5.0 or something like that?
>>     
>
> Sorry, John.  The [whatever] should be the path to your java
> executables - no square brackets needed - that was just me!  So if your
> java binaries are in /usr/lib/jdk/bin then the line would be
>
> export JAVA_HOME=/usr/lib/jdk/bin
>
> or wherever your java binaries live.  Should have been clearer about
> that!  Apologies.
>
>   
>> Plus, as I don't seem to be able to do either "locate xxxx" or
>> "whereis xxxxx" how would I work out what I'm supposed to direct the
>> "export JAVA_HOME=[whatever]" at ??? i.e. I don't know what file or
>> sort of file it needs to be as when I checked the sun site, I found
>> the bit that said about the structure of the JDK 
>> http://java.sun.com/j2se/1.5.0/docs/tooldocs/linux/jdkfiles.html and
>> as I'm sure you can see, it's somewhat confusing for a nugget like me.
>>     
>
> The JAVA_HOME variable needs to be an environment variable.  So, if
> you're starting the tomcat stuff from a terminal each time you can
> simply bash in 
>
> export JAVA_HOME=/usr/lib/jdk/bin
>
> before you start tomcat.  Alternatively to register the environment
> variable with every login, you can put it in your .bash_profile
> or .bashrc files (located in your home directory), before the export
> PATH lines. My .bash_profile file looks like this:-
>
> #Get application paths with getpaths.sh script
> BINPATHS=`$HOME/bin/getpaths.sh`
> PATH=$PATH:$HOME/bin:$BINPATHS
>
> export PATH
>
> You might have something like this in yours:-
>
> JAVA_HOME=/usr/lib/jdk/bin
> PATH=$JAVA_HOME:$PATH:$HOME/bin
>
> export PATH JAVA_HOME
>
> This will register JAVA_HOME as an environment variable for any of
> your login sessions. I'm not convinced you need the JAVA_HOME stuff in
> your path, at least to run up tomcat, but you may need it for other
> stuff I'm not aware of.
>
> Does that make more sense?
Ok, thanks for the amplification. Though I'm still no nearer, as it 
appears that I don't have a "/usr/lib/jdk/bin" and theres no bashprofile 
either (though there is a bashrc).

Sure, things are making more sense, but not enough for me to work out 
what the file is, that I'd need to declare for the JAVA_HOME i.e. I 
really don't know whether it's a library or what? That link in my 
previous post shows the apparent structure of the jdk but apparently 
some distros don't call it the jdk, just the Java SDK (which I can't 
find) and a few other possibles.

It's starting to look like I'll have to give this up as a bad job. I'm 
disappointed with that increasingly more likely event, as I'd really 
like to look at this Openlaszlo app (always fancied putting a few 
"flashlets" into my webpages, even if it's just a stupid picture when 
someone "mouses over" a certain place).

It seems to be just too far over my head - though I'm still convinced 
that I'm missing something obvious. I don't believe that SuSE would make 
it such hard work to use the Java SDK, especially as they supply some 
"SuSEised" rpms for it (albeit with confusing names).

Thankyou for the assist though, very much appreciated.

regards

John D.