/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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.
*/
/**
*
* <p>
* <b>THIS INTERFACE IS SUBJECT TO CHANGE WITHOUT NOTICE.</b>
*
* <p>
* This 'interface' can be implemented by applications and specified to
* processing of the JAXB RI like this:
*
* <pre>
* unmarshaller.setProperty(IDResolver.class.getName(),new MyIDResolverImpl());
* </pre>
*
* <h2>Error Handling</h2>
* <p>
* This component runs inside the JAXB RI unmarshaller. Therefore, it needs
* to coordinate with the JAXB RI unmarshaller when it comes to reporting
* errors. This makes sure that applications see consistent error handling behaviors.
*
* <p>
* When the {@link #startDocument(ValidationEventHandler)} method is invoked,
* the unmarshaller passes in a {@link ValidationEventHandler} that can be used
*
* <p>
* When an error is detected, the error should be first reported to this
* {@link ValidationEventHandler}. If the error is fatal or the event handler
* decided to abort, the implementation should throw a {@link SAXException}.
* This signals the unmarshaller to abort the processing.
*
* @author Kohsuke Kawaguchi
* @since JAXB 2.0 beta
*/
public abstract class IDResolver {
/**
* Called when the unmarshalling starts.
*
* <p>
* Since one {@link Unmarshaller} may be used multiple times
* to unmarshal documents, one {@link IDResolver} may be used multiple times, too.
*
* @param eventHandler
* Any errors found during the unmarshalling should be reported to this object.
*/
}
/**
* Called after the unmarshalling completes.
*
* <p>
* This is a good opporunity to reset any internal state of this object,
* so that it doesn't keep references to other objects unnecessarily.
*/
}
/**
* Binds the given object to the specified ID.
*
* <p>
* While a document is being unmarshalled, every time
* an ID value is found, this method is invoked to
* remember the association between ID and objects.
* This association is supposed to be used later to resolve
* IDREFs.
*
* <p>
* This method is invoked right away as soon as a new ID value is found.
*
* @param id
* The ID value found in the document being unmarshalled.
* Always non-null.
* @param obj
* The object being unmarshalled which is going to own the ID.
* Always non-null.
*/
/**
* Obtains the object to be pointed by the IDREF value.
*
* <p>
* While a document is being unmarshalled, every time
* an IDREF value is found, this method is invoked immediately to
* obtain the object that the IDREF is pointing to.
*
* <p>
* This method returns a {@link Callable} to support forward-references.
* When this method returns with a non-null return value,
* the JAXB RI unmarshaller invokes the {@link Callable#call()} method immediately.
* If the implementation can find the target object (in which case
* it was a backward reference), then a non-null object shall be returned,
* and it is used as the target object.
*
* <p>
* When a forward-reference happens, the <tt>call</tt> method
* should return null. In this case the JAXB RI unmarshaller invokes
* the <tt>call</tt> method again after all the documents are fully unmarshalled.
* If the <tt>call</tt> method still returns null, then the JAXB RI unmarshaller
* treats it as an error.
*
* <p>
* A {@link Callable} object returned from this method may not throw
* any exception other than a {@link SAXException} (which means a fatal error.)
*
* @param id
* The IDREF value found in the document being unmarshalled.
* Always non-null.
* @param targetType
* The expected type to which ID resolves to. JAXB infers this
* information from the signature of the fields that has {@link XmlIDREF}.
* When a property is a collection, this parameter will be the type
* of the individual item in the collection.
* @return
* null if the implementation is sure that the parameter combination
* will never yield a valid object. Otherwise non-null.
*/
}