I downloaded Eclipse Juno package, and extracted it to /opt directory. For installing it, I followed the steps given in this site - Ubuntu Help under the User Installation section. I created the opt_eclipse.desktop file in /usr/share/applications/ directory. Here is the content of my desktop file:

[Desktop Entry]

Type=Application

Name=Eclipse

Comment=Eclipse Integrated Development Environment

Icon=eclipse

Exec=eclipse42

Terminal=false

Categories=Development;IDE;Java;

StartupWMClass=Eclipse

X-Desktop-File-Install-Version=0.20

Then I installed the desktop file on Unity using the following command, as given in this post:

sudo desktop-file-install /usr/share/applications/opt_eclipse.desktop

Then I created the symbolic link using the below command:

sudo ln -s /opt/eclipse/eclipse /usr/local/bin/eclipse42

I also moved the icon to the pixmaps folder using the below command:

cp opt/eclipse/icon.xpm /usr/share/pixmaps/eclipse.xpm

Now, when I go to Unity, I can find the Eclipse Icon. But, when I click it, nothing happens. It doesn't get started. I'm completely new to Ubuntu. Did I miss something out there?