Javah not found error
Either type the full path of the file (or add that folder where it's in) to your path environment variable using export PATH=$PATH:/path/to/java/JDK/bin/folder
. To have that permanently in your path you could add that line to your .bashrc.
For anyone using more recent versions of java (this post is 6 years old as of my writing this) javah
no longer exists in the your Java/JDK/bin folder. Instead, use the command javac -h