jakarta.persistence.Basic Maven / Gradle / Ivy

/*
 * Copyright (c) 2008, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Linda DeMichiel - 2.1
//     Linda DeMichiel - 2.0

package jakarta.persistence;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * The simplest type of mapping to a database column. The
 * Basic annotation can be applied to a persistent
 * property or instance variable of any of the following types: Java
 * primitive types, wrappers of the primitive types, String, 
 * java.math.BigInteger,
 * java.math.BigDecimal,
 * java.util.Date,
 * java.util.Calendar, 
 * java.sql.Date, 
 * java.sql.Time,
 * java.sql.Timestamp, byte[], Byte[],
 * char[], Character[], enums, and any other type that
 * implements java.io.Serializable.
 * 
 *  The use of the Basic annotation is optional for
 * persistent fields and properties of these types.  If the
 * Basic annotation is not specified for such a field or
 * property, the default values of the Basic annotation
 * will apply.
 *
 * 
 *    Example 1:
 *
 *    @Basic
 *    protected String name;
 *
 *    Example 2:
 *
 *    @Basic(fetch=LAZY)
 *    protected String getName() { return name; }
 *
 * 
 * @since 1.0
 */
@Target({METHOD, FIELD}) 
@Retention(RUNTIME)
public @interface Basic {

    /**
     * (Optional) Defines whether the value of the field or property should 
     * be lazily loaded or must be eagerly fetched. The EAGER 
     * strategy is a requirement on the persistence provider runtime 
     * that the value must be eagerly fetched.  The LAZY 
     * strategy is a hint to the persistence provider runtime.
     * If not specified, defaults to EAGER.
     */
    FetchType fetch() default FetchType.EAGER;

    /**
     * (Optional) Defines whether the value of the field or property may be null. 
     * This is a hint and is disregarded for primitive types; it may 
     * be used in schema generation.
     * If not specified, defaults to true.
     */
    boolean optional() default true;
}