install JDK on Debian(Lenny)

1. add in sources.list
    deb http://ftp.de.debian.org/debian/ lenny main non-free
    deb-src http://ftp.de.debian.org/debian/ lenny main non-free
    or 
    deb http://mirrors.kernel.org/debian/ lenny main non-free
    deb-src http://mirrors.kernel.org/debian/ lenny main non-free

2. update by apt-get or aptitude
 2.1 apt-get update
 2.2 aptitude update

3. Install by apt-get or aptitude
 3.1 apt-get install sun-java6-jdk
 3.2 aptitude install sun-java6-jdk

4.Make it available System wide
 update-java-alternatives -s java-6-sun
 echo 'JAVA_HOME="/usr/lib/jvm/java-6-sun"' | tee -a /etc/environment

that's all.