java compiler and interpreter

[blahblahblah]

i have a dual boot system with XP and knoppix.
i am not very well versed when it comes to linux, but i can't really concentrate on learning linux because i am stuck using windows for all the programming stuff i do.

i tried to download the compiler and interpreter from java.sun.com but i really don't know how to make it install or run. as i said im not well versed in linux. can i apt-get them someway?

any help would be appreciated

[hw-tph]

Sun does not use an open license for Java so it is not included with the official Debian archives, so you can't apt-get install with a stock /etc/sources.list file.

However, the Blackdown project (blackdown.org) provides Java packages for Debian (and many others). These are not very up to date (usually) so I just download the Java SDK (not the JRE!) from Sun and install it.

Here's how you do it:

1. Download the "Linux self-extracting file" package from http://java.sun.com/j2se/1.4.2/download.html

2. Create a directory for Java related stuff under /usr/local:
$ cd /usr/local
$ su (enter password for root, note that the prompt changes when you're root)
# mkdir java
# cd java

3. Then you need to run the file. With this file you can do it like this:
# sh j2sdk-1_4_2_01-linux-i586.bin
....or like this:
# chmod +x j2sdk-1_4_2_01-linux-i586.bin (this makes the file executable)
# /home/hw/downloads/j2sdk-1_4_2_01-linux-i586.bin (execute it - run this from the /usr/local/java directory)

4. Now it's installed. Still, the java and javac commands won't work from the command line because the /bin subdirectory from the SDK isn't in the path. We need to add them somehow. There are many different ways of doing this but this is how I usually do it:
Edit /etc/profile (as root) with your favourite text editor. There should be a line that specifies directories that contain executables and should be added to the PATH environment variable. Something like this:
PATH="/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games"
The directories are separated by colons(:). Add a colon at the end of the line (but before the closing quote) and add the Java bin directory. If you followed my outline above it should be /usr/local/java/j2sdk1.4.2/bin/.
Now the line looks like this:
PATH="/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games:/usr/local/java/j2sdk/bin"
Save the file! :)

Either log out and log in again or do a "source /etc/profile" to let the changes take effect. Type "javac" at the shell prompt and you should see the exact same thing as you see on Windows!

hw

[blahblahblah]

thanks a shitload!! i will try this tonight for sure. thank you for your help, ill post if i have any troubles (i probably wont)

[times_r_shitty]

Thanks a shit-load indeed. That is an excellent how-to post. You are a scholar and a gentleman.

[A. Jorge Garcia]

Yup, getting everything from java.sun.com is a good idea. That way you have the full java suite including javac, java, javadoc and appletviewer.

However, I use the following method without installing anything to an hdinstall (also works off a liveCD boot).

http://www.knoppix.net/forum/viewtopic.php?p=38190
http://www.knoppix.net/forum/viewtopic.php?p=38440

Enjoy!

Regards,
AJG

[A. Jorge Garcia]

OK, I just tried to install the *.rpm with alien and kpackage as root. I used the *.rpm for J2SE 1.5 instead of the method listed above because I need to change the version of java system wide so all my users would get the update. The JDK that comes with KNOPPIX doesn't include javax.swing.*, javadoc or appletviewer. So I want all my users to get all this stuff! The problem is that the new java installation isn't available to my users. Did I forget to do something???

TIA,
AJG