Java Architecture for XML Binding (JAXB) is a Java API that allows Java developers to map Java classes to XML representations.

jaxb-api-2.2.12.jar is the JAR file for the JAXB API 2.2 specification. You can download and use it directly without any building process as shown in the last tutorial.

If you want to rebuild the JAR file, you can download the source code at JAXB API Maven Website.

You can also browse the source code below:

⏎ javax/xml/bind/JAXBElement.java

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 * 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
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
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 * When distributing the software, include this License Header Notice in each
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 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
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 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
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 * If you wish your version of this file to be governed by only the CDDL or
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 * elects to include this software in this distribution under the [CDDL or GPL
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 * 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
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 */

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;
}

⏎ javax/xml/bind/JAXBElement.java

Or download all of them as a single archive file:

File name: jaxb-api-2.2.12-sources.jar
File size: 245023 bytes
Release date: 2014-10-10
Download 

⇒ Download jaxb-api-2.2.12.jar File

⇐ Download JAXB 2.2 Specification and API JAR

⇑ JAXB (Java Architecture for XML Binding) API Specification

⇑⇑ FAQ for jaxb-*.jar - Java Architecture for XML Binding