login as root
edit file sources.list
#nano /etc/apt/sources.list
Add
deb http://ftp.us.debian.org/debian/ etch main contrib non-free
Save and Exit
Run Command
#apt-get update
#apt-get install sun-java5-jre
or Build jdk
#apt-get install sun-java5-jdk
Run command
#java -version
java version "1.6.0"
java successfully installed
Good luck
