Making Java 2 work in Debian

Download the j2se SDK from http://java.sun.com. Download the ".bin" file. In a terminal window, run the following commands.

• Switch to root use by issuing
  $ su -
Password:
• cd to the directory where the file was downloaded.
  # cd ~nick/Downloads/
• Change the permission of the file and execute it.
  # chmod +x j2sdk*.bin # ./j2sdk-*.bin
• Make a directory under /usr/local (for example /usr/local/sun).
  # mkdir /usr/local/sun

• Copy the extracted java directory to this newly created directory.
  # mv j2sdk* /usr/local/sun

• Adjust the configurations to ensure that java works correctly. (This is because Debian/Linux uses different versions of java, that may not be reset when the Sun Java is installed.
  # update-alternatives --install /usr/bin/javac javac /usr/local/sun/j2sdk*/bin/javac 120
# update-alternatives --install /usr/bin/java java /usr/local/sun/j2sdk*/bin/java 120

You should now have a working jdk environment, virtual machine and compiler.

You might need to change your /etc/profile adding the proper definitions of some environment variables (CLASSPATH, JAVA_COMPILER and JAVA_HOME) so that Java programs can find the kit you just have installed. Append the following lines to your /etc/profile. The following example show which settings you could add if you had installed Sun's 1.4.2 jdk:

JAVA_COMPILER=/usr/local/sun/j2sdk1.4.2_17/lib:/usr/local/sun/j2sdk1.4.2_17/jre/libexport
export JAVA_COMPILER

JAVA_HOME=/usr/local/sun/j2sdk1.4.2_17/
export JAVA_HOME

PATH=$PATH:/usr/local/sun/j2sdk1.4.2_17/bin
export PATH

This should enable it for all users, except root. If you want to compile and run java programs as root, add the above lines to /root/.bash_profile.

Note: This has been tested only in Debian, although it should work in other distro's too.