Using && in EL results in error: The entity name must immediately follow the '&' in the entity reference

Question

I\'m trying to use a conditional expression in an el expression used in jsf, but it does not work.

Answer 1

You seem to be using Facelets (which is perfectly fine). It's however a XML based view technology. Everything which you write in Facelets has to be syntactically valid XML. The & is in XML a special character denoting the start of an entity like &, <, >,  , etc.

If you would like to represent the & as-is in XML, then you'd have to replace it by &.

However, that's not pretty readable, you would rather like to use the alternative EL operator and for this (see also operators in EL for an overview of all available operators in EL):

All with all, this is in turn pretty clumsy as there's a simpler empty keyword for the purpose of testing both nullness and emptiness. This can in your particular case be used as:

or

or