1 /* 2 * Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.xml.bind.annotation; 27 28 import java.lang.annotation.Retention; 29 import java.lang.annotation.Target; 30 31 import static java.lang.annotation.RetentionPolicy.RUNTIME; 32 import static java.lang.annotation.ElementType.TYPE; 33 34 /** 35 * Maps a class or an enum type to an XML element. 36 * 37 * <p> <b>Usage</b> </p> 38 * <p> 39 * The @XmlRootElement annotation can be used with the following program 40 * elements: 41 * <ul> 42 * <li> a top level class </li> 43 * <li> an enum type </li> 44 * </ul> 45 * 46 * <p>See "Package Specification" in javax.xml.bind.package javadoc for 47 * additional common information.</p> 48 * 49 * <p> 50 * When a top level class or an enum type is annotated with the 51 * @XmlRootElement annotation, then its value is represented 52 * as XML element in an XML document. 53 * 54 * <p> This annotation can be used with the following annotations: 55 * {@link XmlType}, {@link XmlEnum}, {@link XmlAccessorType}, 56 * {@link XmlAccessorOrder}. 57 * <p> 58 59 * <p> 60 * <b>Example 1: </b> Associate an element with XML Schema type 61 * <pre> 62 * // Example: Code fragment 63 * @XmlRootElement 64 * class Point { 65 * int x; 66 * int y; 67 * Point(int _x,int _y) {x=_x;y=_y;} 68 * } 69 * </pre> 70 * 71 * <pre> 72 * //Example: Code fragment corresponding to XML output 73 * marshal( new Point(3,5), System.out); 74 * </pre> 75 * 76 * <pre> 77 * <!-- Example: XML output --> 78 * <point> 79 * <x> 3 </x> 80 * <y> 5 </y> 81 * </point> 82 * </pre> 83 * 84 * The annotation causes an global element declaration to be produced 85 * in the schema. The global element declaration is associated with 86 * the XML schema type to which the class is mapped. 87 * 88 * <pre> 89 * <!-- Example: XML schema definition --> 90 * <xs:element name="point" type="point"/> 91 * <xs:complexType name="point"> 92 * <xs:sequence> 93 * <xs:element name="x" type="xs:int"/> 94 * <xs:element name="y" type="xs:int"/> 95 * </xs:sequence> 96 * </xs:complexType> 97 * </pre> 98 * 99 * <p> 100 * 101 * <b>Example 2: Orthogonality to type inheritance </b> 102 * 103 * <p> 104 * An element declaration annotated on a type is not inherited by its 105 * derived types. The following example shows this. 106 * <pre> 107 * // Example: Code fragment 108 * @XmlRootElement 109 * class Point3D extends Point { 110 * int z; 111 * Point3D(int _x,int _y,int _z) {super(_x,_y);z=_z;} 112 * } 113 * 114 * //Example: Code fragment corresponding to XML output * 115 * marshal( new Point3D(3,5,0), System.out ); 116 * 117 * <!-- Example: XML output --> 118 * <!-- The element name is point3D not point --> 119 * <point3D> 120 * <x>3</x> 121 * <y>5</y> 122 * <z>0</z> 123 * </point3D> 124 * 125 * <!-- Example: XML schema definition --> 126 * <xs:element name="point3D" type="point3D"/> 127 * <xs:complexType name="point3D"> 128 * <xs:complexContent> 129 * <xs:extension base="point"> 130 * <xs:sequence> 131 * <xs:element name="z" type="xs:int"/> 132 * </xs:sequence> 133 * </xs:extension> 134 * </xs:complexContent> 135 * </xs:complexType> 136 * </pre> 137 * 138 * <b>Example 3: </b> Associate a global element with XML Schema type 139 * to which the class is mapped. 140 * <pre> 141 * //Example: Code fragment 142 * @XmlRootElement(name="PriceElement") 143 * public class USPrice { 144 * @XmlElement 145 * public java.math.BigDecimal price; 146 * } 147 * 148 * <!-- Example: XML schema definition --> 149 * <xs:element name="PriceElement" type="USPrice"/> 150 * <xs:complexType name="USPrice"> 151 * <xs:sequence> 152 * <xs:element name="price" type="xs:decimal"/> 153 * </sequence> 154 * </xs:complexType> 155 * </pre> 156 * 157 * @author Sekhar Vajjhala, Sun Microsystems, Inc. 158 * @since JAXB2.0 159 */ 160 @Retention(RUNTIME) 161 @Target({TYPE}) 162 public @interface XmlRootElement { 163 /** 164 * namespace name of the XML element. 165 * <p> 166 * If the value is "##default", then the XML namespace name is derived 167 * from the package of the class ( {@link XmlSchema} ). If the 168 * package is unnamed, then the XML namespace is the default empty 169 * namespace. 170 */ namespace()171 String namespace() default "##default"; 172 173 /** 174 * local name of the XML element. 175 * <p> 176 * If the value is "##default", then the name is derived from the 177 * class name. 178 * 179 */ name()180 String name() default "##default"; 181 182 } 183