Javac problem

[Chaos-Energy]

I used the following commands to set my paths


export JAVA_HOME=/usr/java/jdk1.5.0_11
export PATH=$JAVA_HOME/bin:$PATH

and everything works great (javac & java) but when I exit the terminal, restart it and try javac again it says "command not found". "java" still works but it already worked before I set the paths. It's like it forgets me setting the paths. :S

[gtratter]

I am just a beginner so hopefully what I say is true.
this is your code"


export JAVA_HOME=/usr/java/jdk1.5.0_11
export PATH=$JAVA_HOME/bin:$PATH


I don't see were you set your path, i.e.


JAVA_HOME=$PATH /usr/java/jdk1.5.0_11
export JAVA_HOME


and then I am not sure about your second line...so others will help out....

[Kingsley]

Try
export JAVA_HOME='/usr/java/jdk1.5.0_11'
PATH=.:$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$PATH

And then type "source .bashrc" into the terminal.

[Chaos-Energy]

Still the same problem. :(

[Unterseeboot_234]

Boy, the java paths seems to be a big deal on Ubuntu. Be aware there are three approches.

1. The IDEs such as NetBeans and Eclipse work because they slam the full pathname to the myjava_1.6/bin to find javac, java_vm, appletviewer, etc. every time you hit the Run button.

2. I never had luck modifying the CENTRAL .bash source file within ubuntu so any terminal window you open after that edit will have the correct paths. If you've ever done a .bat file to double-click in Windows while doing java, you can do the same thing with a shell script that you save inside whatever project folder. I prefer this way, because I can make sure the final java will work with the libraries and jars I am going to deploy.


#!/bin/sh
JAVA_HOME="/home/vcbrad/jdk1.5.0_10"
PATH=$JAVA_HOME/bin:$PATH
export PATH JAVA_HOME

java -version
java -classpath ./:/home/vcbrad/javaWork_1_5/java_stoffPlan_4/xperiments/stoffPlan_x_Mar01
java StoffPlanDesk

I deploy the above, composed in Text Editor, saved as java_StoffPlan.sh. I double-click it. Gnome pops up a four-choice dialog and I select "Run In Terminal" Note the colon ( : ) separates classpaths. Note -classpath is all one line. This would be how you run java from a university and/or corporate linux network sitting at the terminal. A shell script lets me include other things like Groovy Script, JMF libraries and jars from other projects included in my final application. I do most of my java code in NetBeans. When I'm ready, a shell script is the blueprint for making a small program written in C to launch a finished product with a desktop icon. And, I usually include the JRE inside the application and make the java link to it.

3. Check out this link, from the forums, to customize your installation of java.

Java Custom Install (http://www.ubuntuforums.org/showthread.php?t=319138)

[Chaos-Energy]

I went through the HowTo guide and it seems to work perfect now. :)

Thanks!

[Keffin]

I know the OPs issue is now resolved, but since people have written odd things about the .bashrc file....

Putting the lines you require in your ~/.bashrc file will ensure that any new terminal you open has these variables set. i.e. edit ~/.bashrc and add the following lines to the bottom:

export JAVA_HOME=/usr/java/jdk1.5.0_11
export PATH=$JAVA_HOME/bin:$PATH
Then either run "source ~/.bashrc", or just close that terminal and fire up a new one. These variables will now always be set. Test using "echo $JAVA_HOME".

[phossal]

I advocated modifying .bashrc to include the JAVA_HOME variable when doing a manual installation (ie, SUN's .bin file) of the Java Development Kit (JDK). It doesn't solve a lot of the problems associated with mixed installation methods of java-dependent programs though. At least, it doesn't do it as cleanly and easily as it could be done.

The package installation of Java takes advantage of update-alternatives, which is a path of links all the way from /usr/bin/java to /etc/alternatives/java to the actual JDK. The best way to enable javac and javaws then (so they're available for updates, etc) is to include them in update-alternatives by doing an installation using the update-alternatives command. Skipping that step though, you can make direct links from the JDK home to /usr/bin like this (in the case of the op):

sudo ln -s /usr/java/jdk1.5.0_11/bin/javac /usr/bin/javac
sudo ln -s /usr/java/jdk1.5.0_11/jre/javaws/javaws /usr/lib/javaws
The additional benefit to this approach is that the commands are available for multiple users.