javax.xml.bind.annotation.XmlRootElement Maven / Gradle / Ivy

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/*
 * Copyright (c) 2004, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package javax.xml.bind.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.RetentionPolicy.RUNTIME;
import static java.lang.annotation.ElementType.TYPE;

/**
 * Maps a class or an enum type to an XML element.
 *
 *  Usage 
 * 
 * The @XmlRootElement annotation can be used with the following program
 * elements: 
 * 
 
 *    a top level class 
 *    an enum type 
 * 
 *
 * See "Package Specification" in javax.xml.bind.package javadoc for
 * additional common information.
 * 
 * 
 * When a top level class or an enum type is annotated with the 
 * @XmlRootElement annotation, then its value is represented 
 * as XML element in an XML document.
 *
 * 
 This annotation can be used with the following annotations:
 * {@link XmlType}, {@link XmlEnum}, {@link XmlAccessorType}, 
 * {@link XmlAccessorOrder}.
 * 

 * 
 * Example 1:  Associate an element with XML Schema type
 * 
 *     // Example: Code fragment
 *     @XmlRootElement
 *     class Point {
 *        int x;
 *        int y;
 *        Point(int _x,int _y) {x=_x;y=_y;}
 *     }
 * 
 *
 *  *     //Example: Code fragment corresponding to XML output
 *     marshal( new Point(3,5), System.out);
 * 
 *
 * {@code
 * 
 *     
 *     
 *        3 
 *        5 
 *     
 * }
 *
 * The annotation causes an global element declaration to be produced
 * in the schema. The global element declaration is associated with
 * the XML schema type to which the class is mapped.
 *
 * {@code
 * 
 *     
 *     
 *     
 *       
 *         
 *         
 *       
 *     
 * }
 *
 * 
 *
 * Example 2: Orthogonality to type inheritance 
 * 
 * 

 * An element declaration annotated on a type is not inherited by its
 * derived types. The following example shows this.
 * 
 *     // Example: Code fragment
 *     @XmlRootElement
 *     class Point3D extends Point {
 *         int z;
 *         Point3D(int _x,int _y,int _z) {super(_x,_y);z=_z;}
 *     }
 *
 *     //Example: Code fragment corresponding to XML output * 
 *     marshal( new Point3D(3,5,0), System.out );
 * {@code
 * 
 *     
 *     
 *     
 *       3
 *       5
 *       0
 *     
 *
 *     
 *     
 *     
 *       
 *         
 *           
 *             
 *           
 *         
 *       
 *     
 * }
 *
 * Example 3:  Associate a global element with XML Schema type
 * to which the class is mapped.
 *  *     //Example: Code fragment
 *     @XmlRootElement(name="PriceElement")
 *     public class USPrice {
 *         @XmlElement
 *         public java.math.BigDecimal price;
 *     }
 * {@code
 * 
 *     
 *     
 *     
 *       
 *         
 *       
 *     
 * }
 *
 * @author Sekhar Vajjhala, Sun Microsystems, Inc.
 * @since 1.6, JAXB 2.0
 */
@Retention(RUNTIME)
@Target({TYPE})
public @interface XmlRootElement {
    /**
     * namespace name of the XML element.
     * 
     * If the value is "##default", then the XML namespace name is derived
     * from the package of the class ( {@link XmlSchema} ). If the
     * package is unnamed, then the XML namespace is the default empty
     * namespace.
     */
    String namespace() default "##default";

    /**
     * local name of the XML element.
     * 
     * If the value is "##default", then the name is derived from the
     * class name. 
     *
     */
    String name() default "##default";

}