/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2004-2017 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://oss.oracle.com/licenses/CDDL+GPL-1.1
* or LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package javax.xml.bind;
import javax.xml.namespace.
QName;
import java.io.
Serializable;
/**
* <p>JAXB representation of an Xml Element.</p>
*
* <p>This class represents information about an Xml Element from both the element
* declaration within a schema and the element instance value within an xml document
* with the following properties
* <ul>
* <li>element's xml tag <b>{@code name}</b></li>
* <li><b>{@code value}</b> represents the element instance's atttribute(s) and content model</li>
* <li>element declaration's <b>{@code declaredType}</b> ({@code xs:element @type} attribute)</li>
* <li><b>{@code scope}</b> of element declaration</li>
* <li>boolean <b>{@code nil}</b> property. (element instance's <b>{@code xsi:nil}</b> attribute)</li>
* </ul>
*
* <p>The {@code declaredType} and {@code scope} property are the
* JAXB class binding for the xml type definition.
* </p>
*
* <p><b>{@code Scope}</b> is either {@link GlobalScope} or the Java class representing the
* complex type definition containing the schema element declaration.
* </p>
*
* <p>There is a property constraint that if <b>{@code value}</b> is {@code null},
* then {@code nil} must be {@code true}. The converse is not true to enable
* representing a nil element with attribute(s). If {@code nil} is true, it is possible
* that {@code value} is non-null so it can hold the value of the attributes
* associated with a nil element.
* </p>
*
* @author Kohsuke Kawaguchi, Joe Fialli
* @since 1.6, JAXB 2.0
*/
public class
JAXBElement<T> implements
Serializable {
/** xml element tag name */
final protected
QName name;
/** Java datatype binding for xml element declaration's type. */
final protected
Class<T>
declaredType;
/** Scope of xml element declaration representing this xml element instance.
* Can be one of the following values:
* - {@link GlobalScope} for global xml element declaration.
* - local element declaration has a scope set to the Java class
* representation of complex type defintion containing
* xml element declaration.
*/
final protected
Class scope;
/** xml element value.
Represents content model and attributes of an xml element instance. */
protected T
value;
/** true iff the xml element instance has xsi:nil="true". */
protected boolean
nil = false;
/**
* Designates global scope for an xml element.
*/
public static final class
GlobalScope {}
/**
* <p>Construct an xml element instance.</p>
*
* @param name Java binding of xml element tag name
* @param declaredType Java binding of xml element declaration's type
* @param scope
* Java binding of scope of xml element declaration.
* Passing null is the same as passing {@code GlobalScope.class}
* @param value
* Java instance representing xml element's value.
* @see #getScope()
* @see #isTypeSubstituted()
*/
public
JAXBElement(
QName name,
Class<T>
declaredType,
Class scope,
T
value) {
if(
declaredType==null ||
name==null)
throw new
IllegalArgumentException();
this.
declaredType =
declaredType;
if(
scope==null)
scope =
GlobalScope.class;
this.
scope =
scope;
this.
name =
name;
setValue(
value);
}
/**
* Construct an xml element instance.
*
* This is just a convenience method for {@code new JAXBElement(name,declaredType,GlobalScope.class,value)}
*/
public
JAXBElement(
QName name,
Class<T>
declaredType, T
value ) {
this(
name,
declaredType,
GlobalScope.class,
value);
}
/**
* Returns the Java binding of the xml element declaration's type attribute.
*/
public
Class<T>
getDeclaredType() {
return
declaredType;
}
/**
* Returns the xml element tag name.
*/
public
QName getName() {
return
name;
}
/**
* <p>Set the content model and attributes of this xml element.</p>
*
* <p>When this property is set to {@code null}, {@code isNil()} must by {@code true}.
* Details of constraint are described at {@link #isNil()}.</p>
*
* @see #isTypeSubstituted()
*/
public void
setValue(T
t) {
this.
value =
t;
}
/**
* <p>Return the content model and attribute values for this element.</p>
*
* <p>See {@link #isNil()} for a description of a property constraint when
* this value is {@code null}</p>
*/
public T
getValue() {
return
value;
}
/**
* Returns scope of xml element declaration.
*
* @see #isGlobalScope()
* @return {@code GlobalScope.class} if this element is of global scope.
*/
public
Class getScope() {
return
scope;
}
/**
* <p>Returns {@code true} iff this element instance content model
* is nil.</p>
*
* <p>This property always returns {@code true} when {@link #getValue()} is null.
* Note that the converse is not true, when this property is {@code true},
* {@link #getValue()} can contain a non-null value for attribute(s). It is
* valid for a nil xml element to have attribute(s).</p>
*/
public boolean
isNil() {
return (
value == null) ||
nil;
}
/**
* <p>Set whether this element has nil content.</p>
*
* @see #isNil()
*/
public void
setNil(boolean
value) {
this.
nil =
value;
}
/* Convenience methods
* (Not necessary but they do unambiguously conceptualize
* the rationale behind this class' fields.)
*/
/**
* Returns true iff this xml element declaration is global.
*/
public boolean
isGlobalScope() {
return this.
scope ==
GlobalScope.class;
}
/**
* Returns true iff this xml element instance's value has a different
* type than xml element declaration's declared type.
*/
public boolean
isTypeSubstituted() {
if(
value==null) return false;
return
value.
getClass() !=
declaredType;
}
private static final long
serialVersionUID = 1L;
}