Java tutorial
/******************************************************************************* * Copyright (c) 2008 - 2013 Oracle Corporation. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * Contributors: * Linda DeMichiel - Java Persistence 2.1 * Linda DeMichiel - Java Persistence 2.0 * ******************************************************************************/ package javax.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; import static javax.persistence.FetchType.EAGER; /** * The simplest type of mapping to a database column. The * <code>Basic</code> 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, <code>String</code>, * <code>java.math.BigInteger</code>, * <code>java.math.BigDecimal</code>, * <code>java.util.Date</code>, * <code>java.util.Calendar</code>, * <code>java.sql.Date</code>, * <code>java.sql.Time</code>, * <code>java.sql.Timestamp</code>, <code>byte[]</code>, <code>Byte[]</code>, * <code>char[]</code>, <code>Character[]</code>, enums, and any other type that * implements <code>java.io.Serializable</code>. * * <p> The use of the <code>Basic</code> annotation is optional for * persistent fields and properties of these types. If the * <code>Basic</code> annotation is not specified for such a field or * property, the default values of the <code>Basic</code> annotation * will apply. * * <pre> * Example 1: * * @Basic * protected String name; * * Example 2: * * @Basic(fetch=LAZY) * protected String getName() { return name; } * * </pre> * @since Java Persistence 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 <code>EAGER</code> * strategy is a requirement on the persistence provider runtime * that the value must be eagerly fetched. The <code>LAZY</code> * strategy is a hint to the persistence provider runtime. * If not specified, defaults to <code>EAGER</code>. */ FetchType fetch() default 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 <code>true</code>. */ boolean optional() default true; }