public interface EnumBase {
        String name();
    }

    public enum TestEnum implements EnumBase {
        FOO, BAR
    }
@MappedSuperclass
    public static abstract class GenericBaseEntity<T extends EnumBase> {

        @Enumerated(EnumType.STRING)
        protected T state;

        public T getState() {
            return state;
        }

        public void setState(T state) {
            this.state = state;
        }
    }

    @Entity
    public static class TestEntity extends GenericBaseEntity<TestEnum> {

        @Id
        private long id;

        protected TestEntity() {
        }

        public TestEntity(long id) {
            this.id = id;
        }

    }