Using public static final fields for annotation parameters in java

I have two questions regarding java annotations:

1. Why does it have to defined as public static final?

2. Why do I have do I have to import them since they're def in the current class?

Is it because in @interface you can only use public static final fields?

And does the import has to do something with optimization?

i.e.

import static db.Rezervare.FINDALL;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

@Entity
@Table(name = "rezervari")
@NamedQueries(
        @NamedQuery(name = FINDALL, query = "SELECT r FROM Rezervare r ORDER BY r.nume")
)
public class Rezervare {

    public static final String FINDALL = "Rezervare.findAll";