Reference for installing Eclipse in Ubuntu 12.10 with the intention of installing Android afterwards. If you are not intending to install Android you can leave out installing ia32-libs and the ADT plugin.

Download Eclipse
Install requirements:

openjdk is for java

ia32-libs is the 32-bits libs for Android (only needed for 64-bit)

sudo apt-get install openjdk-7-jdk ia32-libs


3. Extract the eclipse tar:
 ``` bash
tar -xzf eclipse.tar.gz

Move folder into opt directory:

sudo mv eclipse /opt/


5. Create the desktop profile for unity:
 ``` bash
sudo gedit /usr/share/applications/eclipse.desktop
# Enter the below text:
#######################
[Desktop Entry]
Name=Eclipse
Type=Application
Exec=/opt/eclipse/eclipse
Terminal=false
Icon=/opt/eclipse/icon.xpm
Comment=Integrated Development Environment
NoDisplay=false
Categories=Development;IDE
Name[en]=eclipse.desktop

Create a symbolic link in your bin folder:

sudo ln -s /opt/eclipse/eclipse /usr/local/bin/eclipse


7. Clean launch eclipse for the first time:
 ``` bash
/opt/eclipse/eclipse -clean &

Install ADT Plugin (Help -> Install New Software):

https://dl-ssl.google.com/android/eclipse/