installing JAVA for a newbie.

[gradnite]

If I got it right the "normal" way to install a progrtam on Debian is: open a root shell, type "dpkg apt-get install" followed by the name of the of the program that was downloaded. Correct?

Thanks

Yes, but Java cannot be installed this way?

Also, how do you install the executable java installation file? I downloaded it, but I'm such an idiot that I don't know how to install it. Any help? Thanks.

[xaviers2002]

It is not that complicate....
Open a root shell; than write "chmod +x" "space" "name of the file" "enter".
ES. "chmod +x j2re-1_4_2_05-linux-i586.bin". It should look like this!!!
Than: ./j2re-1_4_2_05-linux-i586.bin.
Voila'!!! Click enter to go at the end of the page: type yes. Wait to see "DONE" close the shell.

[user unknown]

"export JAVA_HOME=/opt/j2sdk"

Do I have to run this from root or command?
Nothing has happened form root.
Thanks

Well - of course you have to set the java home to the dir, where YOU installed it - perhaps it's /opt/j2sdk, perhaps it's not.

run from root? run AS root?
run from COMMAND? (from what else? from PIZZA?)
JAVA_HOME is a variable, which is frequently used by programs, which use java, like a IDE (eclipse) or ant - a build-tool for java like 'make' for c++.

It should be set for every TERMINAL/ ENVIRONMENT where a program is run, which might be interested in the JAVA_HOME.

If you're root and user xaviers on your system, and the only user, and might use java as root, you would set it in /etc/profile.
If you're only using java as xavier, you would put it to /home/xaviers/.bashrc or ~/.bash_login or ~/.profile.

If you only use java for 2 or 3 times, you wouldn't set it at all, or issue the command in the shell directly.

If you're running java for some years and trying differnt versions parallel, you would set it to /opt/java and generate a symbolic link

ln -s /opt/j2sdk-1.4.3 /opt/java
# and for testing remove the link, and create a new one:
ln -s /opt/j2sdk-1.5.0-3 /opt/java

and the JAVA_HOME would automatically point to the appropriate directory via the symbolic link.[/code]

[xaviers2002]

"for mzilikazi"

What is the difference between writing "chmod +x" or not?
I have installed java with both method and everything was fine...
Thanks

[user unknown]

man chmod.

If you CHange MODe of a file +eXecutable (alternatives: Read Write), you make it executable.
Then you can start xy.bin with './xy.bin'.
Else you have to run it as script: 'sh xy.bin'.
If the file is already executable, chmod +x has no effect.

Of course you cannot make any file executable this way.
You only modify an attribute of the file, indicating that it is excecutable.

If you call 'chmod +x flower.bmp' or 'rollOverBeethoven.wav' - the files aren't executable at all.
You will get a message 'no interpreter' or 'unknown file format' if you try to execute them.

[gradnite]

I am further confused.

So, where do I put the java executable file when I download it? Then what do I do to install it?

Thanks.

P.S. Do I use this similar process for installing Real Player because Real Player is not available via apt, is it?

[mzilikazi]

Use the instructions I've already posted.

Go here:

http://java.sun.com/j2se/1.4.2/download.html

Scroll down
Get this:
self-extracting file (j2re-1_4_2_05-linux-i586.bin, 13.72 MB)

Save it to your home directory.
chmod +x j2re-1_4_2_05-linux-i586.bin
./j2re-1_4_2_05-linux-i586.bin

Hit <enter> to get to the bottom of the agreement.
Type 'yes'

[gradnite]

Use the instructions I've already posted.

Go here:

http://java.sun.com/j2se/1.4.2/download.html

Scroll down
Get this:
self-extracting file (j2re-1_4_2_05-linux-i586.bin, 13.72 MB)

Save it to your home directory.
chmod +x j2re-1_4_2_05-linux-i586.bin
./j2re-1_4_2_05-linux-i586.bin

Hit <enter> to get to the bottom of the agreement.
Type 'yes'

Thank you. I got it to work. Is there anyway I can make Mozilla Firefox work with the java too? Right now java only works when I use konquerer.