ubuntu jdk

1. sudo chmod u+x jdk-6u12-linux-i586.bin 
2. sudo ./jdk-6u12-linux-i586.bin
3. sudo vim /etc/profile
   JAVA_HOME=/opt/jdk1.6.0_27
JRE_HOME=$JAVA_HOME/jre
CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
export JAVA_HOME JRE_HOME PATH

4. sudo update-alternatives --install /usr/bin/java java /opt/jdk1.6.0_27/bin/java 2000
sudo update-alternatives --install /usr/bin/javac javac /opt/jdk1.6.0_27/bin/javac 2000

sudo update-alternatives --config java

5. java -version

scala

$ sudo ln -s /usr/share/scala/bin/scala /usr/bin/scala
$ sudo ln -s /usr/share/scala/bin/scalac /usr/bin/scalac
$ sudo ln -s /usr/share/scala/bin/fsc /usr/bin/fsc
$ sudo ln -s /usr/share/scala/bin/sbaz /usr/bin/sbaz
$ sudo ln -s /usr/share/scala/bin/sbaz-setup /usr/bin/sbaz-setup
$ sudo ln -s /usr/share/scala/bin/scaladoc /usr/bin/scaladoc
$ sudo ln -s /usr/share/scala/bin/scalap /usr/bin/scalap

remove

sudo rm -rf /usr/share/scala /usr/bin/scala /usr/bin/scalac /usr/bin/fsc /usr/bin/sbaz /usr/bin/sbaz-setup /usr/bin/scaladoc /usr/bin/scalap