1 /*
   2  * Copyright (c) 2003, 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;
  27 
  28 /**
  29  * A basic event handler interface for validation errors.
  30  *
  31  * <p>
  32  * If an application needs to implement customized event handling, it must
  33  * implement this interface and then register it with either the
  34  * {@link Unmarshaller#setEventHandler(ValidationEventHandler) Unmarshaller},
  35  * the {@link Validator#setEventHandler(ValidationEventHandler) Validator}, or
  36  * the {@link Marshaller#setEventHandler(ValidationEventHandler) Marshaller}.
  37  * The JAXB Provider will then report validation errors and warnings encountered
  38  * during the unmarshal, marshal, and validate operations to these event
  39  * handlers.
  40  *
  41  * <p>
  42  * If the {@code handleEvent} method throws an unchecked runtime exception,
  43  * the JAXB Provider must treat that as if the method returned false, effectively
  44  * terminating whatever operation was in progress at the time (unmarshal,
  45  * validate, or marshal).
  46  *
  47  * <p>
  48  * Modifying the Java content tree within your event handler is undefined
  49  * by the specification and may result in unexpected behaviour.
  50  *
  51  * <p>
  52  * Failing to return false from the {@code handleEvent} method after
  53  * encountering a fatal error is undefined by the specification and may result
  54  * in unexpected behavior.
  55  *
  56  * <p>
  57  * <b>Default Event Handler</b>
  58  * <blockquote>
  59  *    See: <a href="Validator.html#defaulthandler">Validator javadocs</a>
  60  * </blockquote>
  61  *
  62  * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li>
  63  *             <li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li>
  64  *             <li>Joe Fialli, Sun Microsystems, Inc.</li></ul>
  65  * @see Unmarshaller
  66  * @see Validator
  67  * @see Marshaller
  68  * @see ValidationEvent
  69  * @see javax.xml.bind.util.ValidationEventCollector
  70  * @since 1.6, JAXB 1.0
  71  */
  72 public interface ValidationEventHandler {
  73     /**
  74      * Receive notification of a validation warning or error.
  75      *
  76      * The ValidationEvent will have a
  77      * {@link ValidationEventLocator ValidationEventLocator} embedded in it that
  78      * indicates where the error or warning occurred.
  79      *
  80      * <p>
  81      * If an unchecked runtime exception is thrown from this method, the JAXB
  82      * provider will treat it as if the method returned false and interrupt
  83      * the current unmarshal, validate, or marshal operation.
  84      *
  85      * @param event the encapsulated validation event information.  It is a
  86      * provider error if this parameter is null.
  87      * @return true if the JAXB Provider should attempt to continue the current
  88      *         unmarshal, validate, or marshal operation after handling this
  89      *         warning/error, false if the provider should terminate the current
  90      *         operation with the appropriate {@code UnmarshalException},
  91      *         {@code ValidationException}, or {@code MarshalException}.
  92      * @throws IllegalArgumentException if the event object is null.
  93      */
  94     public boolean handleEvent( ValidationEvent event );
  95 
  96 }