How to resolve "referencing entity" nbsp "but not declaring it"

"References the Entity" nbsp ", but does not declare it" or "the entity   Was referenced and not declare "

Facelets is a kind of XML-based view technology. XML has only five predefined entities.

 

Not in. Used in plain HTML or traditional JSPs (: It can't work in jspx, because it's also XML-based!). ATTENTION), when it works only.

To solve this problem, you may want to declare the type of document in your own entity,

<! DOCTYPE HTML [
<! ENTITY nbsp "& #160; >
]>

or use (vi) decimal notation instead of:

& #xA0; or & #160;

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How to resolve "referencing entity" nbsp "but not declaring it"