Access JSF and Primefaces version numbers programmatically

Question

I use PrimeFaces 3.5.x and Mojarra JSF 2.1.x I would like to access and show the versions of both libraries programmatically.

I use the versions as maven2 properties

Answer 1

For JSF:

//returns the major version (2.1)
FacesContext.class.getPackage().getImplementationVersion();

//returns the specification version (2.1)
Package.getPackage("com.sun.faces").getSpecificationVersion();

//returns the minor implementation version (2.1.x)
Package.getPackage("com.sun.faces").getImplementationVersion();

For Primefaces 3.x you can use the Constants class in utils package:

import org.primefaces.util.Constants;

Constants.VERSION