hello guys .i am trying to learn java but i have been confounded by my growing array of problems.i was trying to run the sourcecode for my book thinking in java ,but i could not ,after much ado i decided to try installing version 1.4.3 of the sdk instead of the present version 1.4.1 JRE presently installed on my system.well i did tha,t but so as not to effect a global change on other users of the system i decided to install only in my own home directory instead of in /usr/local. but suprisingly if i try to find out which java is installed it still shows the jre installed on the higher directory.and also when i query if the sdk has been succesfully installed it shows that it has.i want to know if there are any settings i need to tweak to ensure that the sdk i installed is the defaut java environment in this directory .thanks.

Not really clear but I remember that java installation create a directory with the number of version. As a consequence, you can have several version, and use the one you prefer. To change the version you want, just use the environment variable:

PATH=$PATH:/usr/java/j2sdk1.4.2_03/bin:~/bin
CLASSPATH=$CLASSPATH:~/java

For instance I may want to use 1.1 to try my code on old version: I just change the path
PATH=$PATH:/usr/java/j2sdk1.1.0/bin:~/bin
if /usr/java/j2sdk1.1.0 is the installation directory of Java 1.1

I hope this answer you question. Cheers, Pierre-Yves

thanks okay i will be sure to try that out.but i derived some crude means of doing things but its still problematic.let me explain , i found out that my java sdk is installed in /us/java/j2sdk1.4.2_03,so i went into the directory and attempted to run my programs from there.i ued the classpath option and the program compiled but it would not run.here is a sample of what i did.
[tunji@DELTA divelog]$ pico DiveLog.java
[tunji@DELTA divelog]$ cd /usr/
[tunji@DELTA usr]$ cd java
[tunji@DELTA java]$ cd j2sdk1.4.2_03/
[tunji@DELTA j2sdk1.4.2_03]$ javac -classpath /home/tunji/divelog/DiveLog.java
[tunji@DELTA j2sdk1.4.2_03]$ java DiveLog.java
Exception in thread "main" java.lang.NoClassDefFoundError: DiveLog/java
[tunji@DELTA j2sdk1.4.2_03]$ java -classpath /home/tunji/divelog/DiveLog
Usage: java [-options] class [args...]
(to execute a cla
and thats what i got ,i believe i did not define the classpath properlyto the java virtual machine, how can i achieve this. please help me xray this code and give me astep by step guide on how to make my program run.

The classpath plays a role if your code use extra classes (your own for instance) that are not in the current directory. Even in j2sdk..., you use a the javac program that is found tks to your path. You must use the javac of j2sdk.../bin. To check that, just perform a java -version

Whatever the appropriate commands are:
javac DiveLog.java
java DiveLog
to launch the virtual machine.

You are trying to run it wrongly. You've to type only "java DiveLog", without any extension

oops We almost posted at the same time pycoucou

Sorry...

And thanks for the help the other day ! ...

No no, I'm sorry. You've posted first, almost 30 seconds actually .

For the Arrays Dimension thread? You've already understood when I've posted . And hey, you are doing very well with Java!. It's always great to have one more Java programmer around