Two projects are open in NetBeans at the same time.
One of the projects is from javaeetutorial5 example zip, it's called bookstore2. It needs javax.persistence.entity to compile as it uses @Entity annotation. This one does not build due to javax.persistence not found. If I typed 'javax.' then persistance would not be in the list.
Another project is a brand new ejb application with a bean and a web. If I typed 'javax.' then persistence would autocomplete and entity would autocomplete too. The project builds just fine.
Could the reason be that the brand new project was created by NetBeans under its projects folder ~/NetBeansProjects, while the example projects were all unzipped into a subfolder under ~/NetBeansProjects/javaeetutorial5/examples?