/*

 * Copyright (c) 2003, 2015, 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

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 */

package javax.xml.bind;

import javax.xml.bind.annotation.adapters.XmlAdapter;

import javax.xml.bind.attachment.AttachmentUnmarshaller;

import javax.xml.validation.Schema;

import java.io.Reader;

/**

 * The <tt>Unmarshaller</tt> class governs the process of deserializing XML

 * data into newly created Java content trees, optionally validating the XML

 * data as it is unmarshalled.  It provides an overloading of unmarshal methods

 * for many different input kinds.

 *

 * <p>

 * Unmarshalling from a File:

 * <blockquote>

 *    <pre>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *       Object o = u.unmarshal( new File( "nosferatu.xml" ) );

 *    </pre>

 * </blockquote>

 *

 *

 * <p>

 * Unmarshalling from an InputStream:

 * <blockquote>

 *    <pre>

 *       InputStream is = new FileInputStream( "nosferatu.xml" );

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *       Object o = u.unmarshal( is );

 *    </pre>

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a URL:

 * <blockquote>

 *    <pre>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *       URL url = new URL( "http://beaker.east/nosferatu.xml" );

 *       Object o = u.unmarshal( url );

 *    </pre>

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a StringBuffer using a

 * <tt>javax.xml.transform.stream.StreamSource</tt>:

 * <blockquote>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *       Object o = u.unmarshal( new StreamSource( new StringReader( xmlStr.toString() ) ) );

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a <tt>org.w3c.dom.Node</tt>:

 * <blockquote>

 *    <pre>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *

 *       DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

 *       dbf.setNamespaceAware(true);

 *       DocumentBuilder db = dbf.newDocumentBuilder();

 *       Document doc = db.parse(new File( "nosferatu.xml"));

 *       Object o = u.unmarshal( doc );

 *    </pre>

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a <tt>javax.xml.transform.sax.SAXSource</tt> using a

 * client specified validating SAX2.0 parser:

 * <blockquote>

 *    <pre>

 *       // configure a validating SAX2.0 parser (Xerces2)

 *       static final String JAXP_SCHEMA_LANGUAGE =

 *           "http://java.sun.com/xml/jaxp/properties/schemaLanguage";

 *       static final String JAXP_SCHEMA_LOCATION =

 *           "http://java.sun.com/xml/jaxp/properties/schemaSource";

 *       static final String W3C_XML_SCHEMA =

 *           "http://www.w3.org/2001/XMLSchema";

 *

 *       System.setProperty( "javax.xml.parsers.SAXParserFactory",

 *                           "org.apache.xerces.jaxp.SAXParserFactoryImpl" );

 *

 *       SAXParserFactory spf = SAXParserFactory.newInstance();

 *       spf.setNamespaceAware(true);

 *       spf.setValidating(true);

 *       SAXParser saxParser = spf.newSAXParser();

 *

 *       try {

 *           saxParser.setProperty(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);

 *           saxParser.setProperty(JAXP_SCHEMA_LOCATION, "http://....");

 *       } catch (SAXNotRecognizedException x) {

 *           // exception handling omitted

 *       }

 *

 *       XMLReader xmlReader = saxParser.getXMLReader();

 *       SAXSource source =

 *           new SAXSource( xmlReader, new InputSource( "http://..." ) );

 *

 *       // Setup JAXB to unmarshal

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *       ValidationEventCollector vec = new ValidationEventCollector();

 *       u.setEventHandler( vec );

 *

 *       // turn off the JAXB provider's default validation mechanism to

 *       // avoid duplicate validation

 *       u.setValidating( false )

 *

 *       // unmarshal

 *       Object o = u.unmarshal( source );

 *

 *       // check for events

 *       if( vec.hasEvents() ) {

 *          // iterate over events

 *       }

 *    </pre>

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a StAX XMLStreamReader:

 * <blockquote>

 *    <pre>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *

 *       javax.xml.stream.XMLStreamReader xmlStreamReader =

 *           javax.xml.stream.XMLInputFactory().newInstance().createXMLStreamReader( ... );

 *

 *       Object o = u.unmarshal( xmlStreamReader );

 *    </pre>

 * </blockquote>

 *

 * <p>

 * Unmarshalling from a StAX XMLEventReader:

 * <blockquote>

 *    <pre>

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *

 *       javax.xml.stream.XMLEventReader xmlEventReader =

 *           javax.xml.stream.XMLInputFactory().newInstance().createXMLEventReader( ... );

 *

 *       Object o = u.unmarshal( xmlEventReader );

 *    </pre>

 * </blockquote>

 *

 * <p>

 * <a name="unmarshalEx"></a>

 * <b>Unmarshalling XML Data</b><br>

 * <blockquote>

 * Unmarshalling can deserialize XML data that represents either an entire XML document

 * or a subtree of an XML document. Typically, it is sufficient to use the

 * unmarshalling methods described by

 * <a href="#unmarshalGlobal">Unmarshal root element that is declared globally</a>.

 * These unmarshal methods utilize {@link JAXBContext}'s mapping of global XML element

 * declarations and type definitions to JAXB mapped classes to initiate the

 * unmarshalling of the root element of  XML data.  When the {@link JAXBContext}'s

 * mappings are not sufficient to unmarshal the root element of XML data,

 * the application can assist the unmarshalling process by using the

 * <a href="#unmarshalByDeclaredType">unmarshal by declaredType methods</a>.

 * These methods are useful for unmarshalling XML data where

 * the root element corresponds to a local element declaration in the schema.

 * </blockquote>

 *

 * <blockquote>

 * An unmarshal method never returns null. If the unmarshal process is unable to unmarshal

 * the root of XML content to a JAXB mapped object, a fatal error is reported that

 * terminates processing by throwing JAXBException.

 * </blockquote>

 *

 * <p>

 * <a name="unmarshalGlobal"></a>

 * <b>Unmarshal a root element that is globally declared</b><br>

 * <blockquote>

 * The unmarshal methods that do not have an <tt>declaredType</tt> parameter use

 * {@link JAXBContext} to unmarshal the root element of an XML data. The {@link JAXBContext}

 * instance is the one that was used to create this <tt>Unmarshaller</tt>. The {@link JAXBContext}

 * instance maintains a mapping of globally declared XML element and type definition names to

 * JAXB mapped classes. The unmarshal method checks if {@link JAXBContext} has a mapping

 * from the root element's XML name and/or <tt>@xsi:type</tt> to a JAXB mapped class.  If it does, it umarshalls the

 * XML data using the appropriate JAXB mapped class. Note that when the root element name is unknown and the root

 * element has an <tt>@xsi:type</tt>, the XML data is unmarshalled

 * using that JAXB mapped class as the value of a {@link JAXBElement}.

 * When the {@link JAXBContext} object does not have a mapping for the root element's name

 * nor its <tt>@xsi:type</tt>, if it exists,

 * then the unmarshal operation will abort immediately by throwing a {@link UnmarshalException

 * UnmarshalException}. This exception scenario can be worked around by using the unmarshal by

 * declaredType methods described in the next subsection.

 * </blockquote>

 *

 * <p>

 * <a name="unmarshalByDeclaredType"></a>

 * <b>Unmarshal by Declared Type</b><br>

 * <blockquote>

 * The unmarshal methods with a <code>declaredType</code> parameter enable an

 * application to deserialize a root element of XML data, even when

 * there is no mapping in {@link JAXBContext} of the root element's XML name.

 * The unmarshaller unmarshals the root element using the application provided

 * mapping specified as the <tt>declaredType</tt> parameter.

 * Note that even when the root element's element name is mapped by {@link JAXBContext},

 * the <code>declaredType</code> parameter overrides that mapping for

 * deserializing the root element when using these unmarshal methods.

 * Additionally, when the root element of XML data has an <tt>xsi:type</tt> attribute and

 * that attribute's value references a type definition that is mapped

 * to a JAXB mapped class by {@link JAXBContext}, that the root

 * element's <tt>xsi:type</tt> attribute takes

 * precedence over the unmarshal methods <tt>declaredType</tt> parameter.

 * instance. The table below shows how the properties of the returned JAXBElement

 * instance are set.

 *

 * <a name="unmarshalDeclaredTypeReturn"></a>

 *   <table summary="" border="2" rules="all" cellpadding="4">

 *   <thead>

 *     <tr>

 *       <th align="center" colspan="2">

 *       Unmarshal By Declared Type returned JAXBElement

 *       </tr>

 *     <tr>

 *       <th>JAXBElement Property</th>

 *       <th>Value</th>

 *     </tr>

 *     <tr>

 *       <td>name</td>

 *       <td><code>xml element name</code></td>

 *     </tr>

 *   </thead>

 *   <tbody>

 *     <tr>

 *       <td>value</td>

 *       <td><code>instanceof declaredType</code></td>

 *     </tr>

 *     <tr>

 *       <td>declaredType</td>

 *       <td>unmarshal method <code>declaredType</code> parameter</td>

 *     </tr>

 *     <tr>

 *       <td>scope</td>

 *       <td><code>null</code> <i>(actual scope is unknown)</i></td>

 *     </tr>

 *   </tbody>

 *  </table>

 * </blockquote>

 *

 * <p>

 * The following is an example of

 * <a href="#unmarshalByDeclaredType">unmarshal by declaredType method</a>.

 * <p>

 * Unmarshal by declaredType from a <tt>org.w3c.dom.Node</tt>:

 * <blockquote>

 *       Schema fragment for example

 *                    ...

 *

 *       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

 *       Unmarshaller u = jc.createUnmarshaller();

 *

 *       DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

 *       dbf.setNamespaceAware(true);

 *       DocumentBuilder db = dbf.newDocumentBuilder();

 *       Document doc = db.parse(new File( "nosferatu.xml"));

 *       Element  fooSubtree = ...; // traverse DOM till reach xml element foo, constrained by a

 *                                  // local element declaration in schema.

 *

 *       // FooType is the JAXB mapping of the type of local element declaration foo.

 * </blockquote>

 *

 * <p>

 * <b>Support for SAX2.0 Compliant Parsers</b><br>

 * <blockquote>

 * A client application has the ability to select the SAX2.0 compliant parser

 * of their choice.  If a SAX parser is not selected, then the JAXB Provider's

 * default parser will be used.  Even though the JAXB Provider's default parser

 * is not required to be SAX2.0 compliant, all providers are required to allow

 * a client application to specify their own SAX2.0 parser.  Some providers may

 * require the client application to specify the SAX2.0 parser at schema compile

 * time. See {@link #unmarshal(javax.xml.transform.Source) unmarshal(Source)}

 * for more detail.

 * </blockquote>

 *

 * <p>

 * <b>Validation and Well-Formedness</b><br>

 * <blockquote>

 * <p>

 * A client application can enable or disable JAXP 1.3 validation

 * mechanism via the <tt>setSchema(javax.xml.validation.Schema)</tt> API.

 * Sophisticated clients can specify their own validating SAX 2.0 compliant

 * parser and bypass the JAXP 1.3 validation mechanism using the

 * {@link #unmarshal(javax.xml.transform.Source) unmarshal(Source)}  API.

 *

 * <p>

 * Since unmarshalling invalid XML content is defined in JAXB 2.0,

 * the Unmarshaller default validation event handler was made more lenient

 * than in JAXB 1.0.  When schema-derived code generated

 * by JAXB 1.0 binding compiler is registered with {@link JAXBContext},

 * the default unmarshal validation handler is

 * {@link javax.xml.bind.helpers.DefaultValidationEventHandler} and it

 * terminates the marshal  operation after encountering either a fatal error or an error.

 * For a JAXB 2.0 client application, there is no explicitly defined default

 * validation handler and the default event handling only

 * terminates the unmarshal operation after encountering a fatal error.

 *

 * </blockquote>

 *

 * <p>

 * <a name="supportedProps"></a>

 * <b>Supported Properties</b><br>

 * <blockquote>

 * <p>

 * There currently are not any properties required to be supported by all

 * JAXB Providers on Unmarshaller.  However, some providers may support

 * their own set of provider specific properties.

 * </blockquote>

 *

 * <p>

 * <a name="unmarshalEventCallback"></a>

 * <b>Unmarshal Event Callbacks</b><br>

 * <blockquote>

 * The {@link Unmarshaller} provides two styles of callback mechanisms

 * that allow application specific processing during key points in the

 * unmarshalling process.  In 'class defined' event callbacks, application

 * specific code placed in JAXB mapped classes is triggered during

 * unmarshalling.  'External listeners' allow for centralized processing

 * of unmarshal events in one callback method rather than by type event callbacks.

 * <p>

 * 'Class defined' event callback methods allow any JAXB mapped class to specify

 * its own specific callback methods by defining methods with the following method signature:

 * <blockquote>

 * <pre>

 *   // This method is called immediately after the object is created and before the unmarshalling of this

 *   // object begins. The callback provides an opportunity to initialize JavaBean properties prior to unmarshalling.

 *   void beforeUnmarshal(Unmarshaller, Object parent);

 *

 *   //This method is called after all the properties (except IDREF) are unmarshalled for this object,

 *   //but before this object is set to the parent object.

 *   void afterUnmarshal(Unmarshaller, Object parent);

 * </pre>

 * </blockquote>

 * The class defined callback methods should be used when the callback method requires

 * access to non-public methods and/or fields of the class.

 * <p>

 * The external listener callback mechanism enables the registration of a {@link Listener}

 * instance with an {@link Unmarshaller#setListener(Listener)}. The external listener receives all callback events,

 * allowing for more centralized processing than per class defined callback methods.  The external listener

 * receives events when unmarshalling process is marshalling to a JAXB element or to JAXB mapped class.

 * <p>

 * The 'class defined' and external listener event callback methods are independent of each other,

 * both can be called for one event.  The invocation ordering when both listener callback methods exist is

 * defined in {@link Listener#beforeUnmarshal(Object, Object)} and {@link Listener#afterUnmarshal(Object, Object)}.

* <p>

 * An event callback method throwing an exception terminates the current unmarshal process.

 *

 * </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 JAXBContext

 * @see Marshaller

 * @see Validator

 * @since 1.6, JAXB 1.0

 */

public interface Unmarshaller {

    /**

     * Unmarshal XML data from the specified file and return the resulting

     * content tree.

     *

     * <p>

     * Implements <a href="#unmarshalGlobal">Unmarshal Global Root Element</a>.

     *

     * @param f the file to unmarshal XML data from

     * @return the newly created root object of the java content tree

     *

     * @throws JAXBException

     *     If any unexpected errors occur while unmarshalling

     * @throws UnmarshalException

     *     If the {@link ValidationEventHandler ValidationEventHandler}

     *     returns false from its <tt>handleEvent</tt> method or the

     *     <tt>Unmarshaller</tt> is unable to perform the XML to Java

     *     binding.  See <a href="#unmarshalEx">Unmarshalling XML Data</a>

     * @throws IllegalArgumentException

     *      If the file parameter is null

     */

    public Object unmarshal( java.io.File f ) throws JAXBException;

    /**

     * Unmarshal XML data from the specified InputStream and return the

     * resulting content tree.  Validation event location information may

     * be incomplete when using this form of the unmarshal API.

     *

     * <p>

     * Implements <a href="#unmarshalGlobal">Unmarshal Global Root Element</a>.

     *

     * @param is the InputStream to unmarshal XML data from

     * @return the newly created root object of the java content tree

     *

     * @throws JAXBException

     *     If any unexpected errors occur while unmarshalling

     * @throws UnmarshalException

     *     If the {@link ValidationEventHandler ValidationEventHandler}

     *     returns false from its <tt>handleEvent</tt> method or the

     *     <tt>Unmarshaller</tt> is unable to perform the XML to Java

     *     binding.  See <a href="#unmarshalEx">Unmarshalling XML Data</a>

     * @throws IllegalArgumentException

     *      If the InputStream parameter is null

     */

    public Object unmarshal( java.io.InputStream is ) throws JAXBException;

    /**

     * Unmarshal XML data from the specified Reader and return the

     * resulting content tree.  Validation event location information may

     * be incomplete when using this form of the unmarshal API,

     * because a Reader does not provide the system ID.

     *

     * <p>

     * Implements <a href="#unmarshalGlobal">Unmarshal Global Root Element</a>.

     *

     * @param reader the Reader to unmarshal XML data from

     * @return the newly created root object of the java content tree

     *

     * @throws JAXBException

     *     If any unexpected errors occur while unmarshalling

     * @throws UnmarshalException

     *     If the {@link ValidationEventHandler ValidationEventHandler}

     *     returns false from its <tt>handleEvent</tt> method or the

     *     <tt>Unmarshaller</tt> is unable to perform the XML to Java

     *     binding.  See <a href="#unmarshalEx">Unmarshalling XML Data</a>

     * @throws IllegalArgumentException

     *      If the InputStream parameter is null

     * @since 1.6, JAXB 2.0

     */

    public Object unmarshal( Reader reader ) throws JAXBException;

    /**

     * Unmarshal XML data from the specified URL and return the resulting

     * content tree.

     *

     * <p>

     * Implements <a href="#unmarshalGlobal">Unmarshal Global Root Element</a>.

     *

     * @param url the url to unmarshal XML data from

     * @return the newly created root object of the java content tree

     *

     * @throws JAXBException

     *     If any unexpected errors occur while unmarshalling

     * @throws UnmarshalException

     *     If the {@link ValidationEventHandler ValidationEventHandler}

     *     returns false from its <tt>handleEvent</tt> method or the

     *     <tt>Unmarshaller</tt> is unable to perform the XML to Java

     *     binding.  See <a href="#unmarshalEx">Unmarshalling XML Data</a>

     * @throws IllegalArgumentException

     *      If the URL parameter is null

     */

    public Object unmarshal( java.net.URL url ) throws JAXBException;

    /**

     * Unmarshal XML data from the specified SAX InputSource and return the

     * resulting content tree.

     *

     * <p>

     * Implements <a href="#unmarshalGlobal">Unmarshal Global Root Element</a>.

     *

     * @param source the input source to unmarshal XML data from

     * @return the newly created root object of the java content tree

     *

     * @throws JAXBException

     *     If any unexpected errors occur while unmarshalling

     * @throws UnmarshalException

     *     If the {@link ValidationEventHandler ValidationEventHandler}

     *     returns false from its <tt>handleEvent</tt> method or the

     *     <tt>Unmarshaller</tt> is unable to perform the XML to Java

     *     binding.  See <a href="#unmarshalEx">Unmarshalling XML Data</a>

     * @throws IllegalArgumentException

     *      If the InputSource parameter is null

     */

    public Object unmarshal( org.xml.sax.InputSource source ) throws JAXBException;

    /**

     * Unmarshal global XML data from the specified DOM tree and return the resulting