The class javax.persistence.ForeignKey contains the following code:

@Target({})
@Retention(RUNTIME)
public @interface ForeignKey {

In other words: It specifies no targets. Consequently, it isn't possible to use the annotation at all. The correct code would be:

@Target(

)
@Retention(RUNTIME)
public @interface ForeignKey {

(Copied from org.hibernate.annotations.ForeignKey.)

Workaround: Use the deprecated org.hibernate.annotations.ForeignKey.)