jaxws/src/java.xml.bind/share/classes/javax/xml/bind/JAXBElement.java
changeset 25871 b80b84e87032
parent 25840 c2002453eec3
child 32795 5a5710ee05a0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jaxws/src/java.xml.bind/share/classes/javax/xml/bind/JAXBElement.java	Sun Aug 17 15:52:15 2014 +0100
@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+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><tt>name</tt></b></li>
+ *   <li><b><tt>value</tt></b> represents the element instance's atttribute(s) and content model</li>
+ *   <li>element declaration's <b><tt>declaredType</tt></b> (<tt>xs:element @type</tt> attribute)</li>
+ *   <li><b><tt>scope</tt></b> of element declaration</li>
+ *   <li>boolean <b><tt>nil</tt></b> property. (element instance's <tt><b>xsi:nil</b></tt> attribute)</li>
+ * </ul>
+ *
+ * <p>The <tt>declaredType</tt> and <tt>scope</tt> property are the
+ * JAXB class binding for the xml type definition.
+ * </p>
+ *
+ * <p><b><tt>Scope</tt></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><tt>value</tt></b> is <tt>null</tt>,
+ * then <tt>nil</tt> must be <tt>true</tt>. The converse is not true to enable
+ * representing a nil element with attribute(s). If <tt>nil</tt> is true, it is possible
+ * that <tt>value</tt> 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 <tt>GlobalScope.class</tt>
+     * @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 <tt>new JAXBElement(name,declaredType,GlobalScope.class,value)</tt>
+     */
+    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 <tt>null</tt>, <tt>isNil()</tt> must by <tt>true</tt>.
+     *    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 <tt>null</tt></p>
+     */
+    public T getValue() {
+        return value;
+    }
+
+    /**
+     * Returns scope of xml element declaration.
+     *
+     * @see #isGlobalScope()
+     * @return <tt>GlobalScope.class</tt> if this element is of global scope.
+     */
+    public Class getScope() {
+        return scope;
+    }
+
+    /**
+     * <p>Returns <tt>true</tt> iff this element instance content model
+     * is nil.</p>
+     *
+     * <p>This property always returns <tt>true</tt> when {@link #getValue()} is null.
+     * Note that the converse is not true, when this property is <tt>true</tt>,
+     * {@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;
+}