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

jaxb-api-2.3.1.jar is the JAR file for the JAXB API 2.3 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/ValidationEventHandler.java

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 *
 * 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:
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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
 * Version 2] license."  If you don't indicate a single choice of license, a
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 */

package javax.xml.bind;

/**
 * A basic event handler interface for validation errors.
 *
 * <p>
 * If an application needs to implement customized event handling, it must
 * implement this interface and then register it with either the 
 * {@link Unmarshaller#setEventHandler(ValidationEventHandler) Unmarshaller}, 
 * the {@link Validator#setEventHandler(ValidationEventHandler) Validator}, or 
 * the {@link Marshaller#setEventHandler(ValidationEventHandler) Marshaller}.  
 * The JAXB Provider will then report validation errors and warnings encountered
 * during the unmarshal, marshal, and validate operations to these event 
 * handlers.
 *
 * <p>
 * If the {@code handleEvent} method throws an unchecked runtime exception,
 * the JAXB Provider must treat that as if the method returned false, effectively
 * terminating whatever operation was in progress at the time (unmarshal, 
 * validate, or marshal).
 * 
 * <p>
 * Modifying the Java content tree within your event handler is undefined
 * by the specification and may result in unexpected behaviour.
 *
 * <p>
 * Failing to return false from the {@code handleEvent} method after
 * encountering a fatal error is undefined by the specification and may result 
 * in unexpected behavior.
 *
 * <p>
 * <b>Default Event Handler</b>
 * <blockquote>
 *    See: <a href="Validator.html#defaulthandler">Validator javadocs</a>
 * </blockquote>
 *
 * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li>
 *             <li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li>
 *             <li>Joe Fialli, Sun Microsystems, Inc.</li></ul>
 * @see Unmarshaller
 * @see Validator
 * @see Marshaller
 * @see ValidationEvent
 * @see javax.xml.bind.util.ValidationEventCollector
 * @since 1.6, JAXB 1.0
 */
public interface ValidationEventHandler {
    /**
     * Receive notification of a validation warning or error.  
     * 
     * The ValidationEvent will have a 
     * {@link ValidationEventLocator ValidationEventLocator} embedded in it that 
     * indicates where the error or warning occurred.
     *
     * <p>
     * If an unchecked runtime exception is thrown from this method, the JAXB
     * provider will treat it as if the method returned false and interrupt
     * the current unmarshal, validate, or marshal operation.
     * 
     * @param event the encapsulated validation event information.  It is a 
     * provider error if this parameter is null.
     * @return true if the JAXB Provider should attempt to continue the current
     *         unmarshal, validate, or marshal operation after handling this 
     *         warning/error, false if the provider should terminate the current 
     *         operation with the appropriate {@code UnmarshalException},
     *         {@code ValidationException}, or {@code MarshalException}.
     * @throws IllegalArgumentException if the event object is null.
     */
    public boolean handleEvent( ValidationEvent event );
    
}

⏎ javax/xml/bind/ValidationEventHandler.java

Or download all of them as a single archive file:

File name: jaxb-api-2.3.1-sources.jar
File size: 271123 bytes
Release date: 2018-10-10
Download 

⇒ Download JAXB 2.2 Specification and API JAR

⇐ Download JAXB 2.3 Specification and API JAR

⇑ JAXB (Java Architecture for XML Binding) API Specification

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