问题
I have a maven project in Eclipse Java EE IDE for Web Developers. But when I go enable JPA facet, I cannot choose JPA (there is no JPA option). Have I forgotten to include some dependency?

I've installed the following Maven dependencies: eclipslink-2.5.-RC1.jar, javax.persistence-2.0.0.jar, and mysql-connector-java-5.1.9.jar.
I get the following warning on my project:
Implementation of project facet jpt.jpa could not be found. Functionality will be limited.
UPDATE: I have the Dali Java Persistence Tools installed.

回答1:
The JPA facet is not dependent on what is in your pom.xml. Check to make sure you have these plugins installed (The ones highlighted in blue).
Help -> Install New Software... -> What is already installed?

If they're missing you can find the plugin here: http://www.eclipse.org/webtools/dali/
Hope this helps!
来源:https://stackoverflow.com/questions/17299667/cannot-create-jpa-facet-project-facet-jpt-jpa-could-not-be-found