Annotation Interface StaticMetamodel

@Target(TYPE)
@Retention(RUNTIME)
public @interface StaticMetamodel

The StaticMetamodel annotation specifies that the class is a metamodel class that represents the Java type designated by the value() element. The Java type might be:

• an entity class, mapped superclass, or embeddable class,
• a class with one or more NamedQuery or NamedNativeQuery annotations, or
• a class with one or more methods annotated JakartaQuery or NativeQuery.

Typically, a static metamodel class is generated by an annotation processor according to the specification of the Jakarta Persistence canonical metamodel. Metamodel classes which do not conform to this specification are not portable between persistence providers.

The canonical metamodel for a class X belongs to the same package as X, and is named X_.

Suppose the persistence unit contains the following entity class:

package org.example;
import jakarta.persistence.*;

@Entity class Book {
    @Id String isbn;
    ...
}

Then the canonical metamodel class is org.example.Book_.

import org.example.*;
import jakarta.persistence.*;
...
    EntityType<Book> bookType = Book_.class_;
    SingularAttribute<Book,String> isbn = Book_.isbn;

Similarly, suppose the persistence unit contains the following interface annotated @NamedQuery:

package com.acme.orders;
import jakarta.persistence.*;

@NamedQuery(name = "allOrdersBySku",
            query = "select o from Order o join i.items i where i.sku = ?1")
...
interface OrderQueries { ... }

Then the canonical metamodel class is com.acme.orders.OrderQueries_.

import com.acme.orders.*;
import jakarta.persistence.*;
...
    var ordersForSku =
            entityManager.createQuery(OrderQueries_._allOrdersBySku_)
                    .setParameter(1, sku)
                    .getResultList();

Note that the canonical metamodel field for the named query allOrdersBySku is named _allOrdersBySku_ to avoid naming collisions.

Since:

2.0

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
Class<?>	value	Class being modelled by the annotated class.

Element Details

value

@Nonnull
Class<?> value

Class being modelled by the annotated class.