[Eclipse] If you encounter this error message

Cannot complete the install because one or more required items could not be found. Software being installed: Android Development Tools 15.0.0.v201110251216-213216 (com.android.ide.eclipse.adt.feature.group 15.0.0.v201110251216-213216) Missing requirement: Android Development Tools 15.0.0.v201110251216-213216 (com.android.ide.eclipse.adt.feature.group 15.0.0.v201110251216-213216) requires 'org.eclipse.wst.sse.core 0.0.0' but it could not be found

While installing android adt plugin, you probably missing a library with ssl.
So just try this.

$ sudo apt-get install openssl libssl-dev