1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
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24 */
25
26package javax.xml.bind;
27
28import org.w3c.dom.Node;
29
30import javax.xml.validation.Schema;
31
32/**
33 * Enable synchronization between XML infoset nodes and JAXB objects
34 * representing same XML document.
35 *
36 * <p>
37 * An instance of this class maintains the association between XML nodes of
38 * an infoset preserving view and a JAXB representation of an XML document.
39 * Navigation between the two views is provided by the methods
40 * {@link #getXMLNode(Object)} and {@link #getJAXBNode(Object)}.
41 *
42 * <p>
43 * Modifications can be made to either the infoset preserving view or the
44 * JAXB representation of the document while the other view remains
45 * unmodified. The binder is able to synchronize the changes made in the
46 * modified view back into the other view using the appropriate
47 * Binder update methods, {@link #updateXML(Object, Object)} or
48 * {@link #updateJAXB(Object)}.
49 *
50 * <p>
51 * A typical usage scenario is the following:
52 * <ul>
53 *   <li>load XML document into an XML infoset representation</li>
54 *   <li>{@link #unmarshal(Object)} XML infoset view to JAXB view.
55 *       (Note to conserve resources, it is possible to only unmarshal a
56 *       subtree of the XML infoset view to the JAXB view.)</li>
57 *   <li>application access/updates JAXB view of XML document.</li>
58 *   <li>{@link #updateXML(Object)} synchronizes modifications to JAXB view
59 *       back into the XML infoset view. Update operation preserves as
60 *       much of original XML infoset as possible (i.e. comments, PI, ...)</li>
61 * </ul>
62 *
63 * <p>
64 * A Binder instance is created using the factory method
65 * {@link JAXBContext#createBinder()} or {@link JAXBContext#createBinder(Class)}.
66 *
67 * <p>
68 * The template parameter, <code>XmlNode</code>, is the
69 * root interface/class for the XML infoset preserving representation.
70 * A Binder implementation is required to minimally support
71 * an <code>XmlNode</code> value of <code>org.w3c.dom.Node.class</code>.
72 * A Binder implementation can support alternative XML infoset
73 * preserving representations.
74 *
75 * @author
76 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
77 *     Joseph Fialli
78 *
79 * @since 1.6, JAXB 2.0
80 */
81public abstract class Binder<XmlNode> {
82    /**
83     * Unmarshal XML infoset view to a JAXB object tree.
84     *
85     * <p>
86     * This method is similar to {@link Unmarshaller#unmarshal(Node)}
87     * with the addition of maintaining the association between XML nodes
88     * and the produced JAXB objects, enabling future update operations,
89     * {@link #updateXML(Object, Object)} or {@link #updateJAXB(Object)}.
90     *
91     * <p>
92     * When {@link #getSchema()} is non-null, <code>xmlNode</code>
93     * and its descendants is validated during this operation.
94     *
95     * <p>
96     * This method throws {@link UnmarshalException} when the Binder's
97     * {@link JAXBContext} does not have a mapping for the XML element name
98     * or the type, specifiable via {@code @xsi:type}, of {@code xmlNode}
99     * to a JAXB mapped class. The method {@link #unmarshal(Object, Class)}
100     * enables an application to specify the JAXB mapped class that
101     * the {@code xmlNode} should be mapped to.
102     *
103     * @param xmlNode
104     *      the document/element to unmarshal XML data from.
105     *
106     * @return
107     *      the newly created root object of the JAXB object tree.
108     *
109     * @throws JAXBException
110     *      If any unexpected errors occur while unmarshalling
111     * @throws UnmarshalException
112     *     If the {@link ValidationEventHandler ValidationEventHandler}
113     *     returns false from its {@code handleEvent} method or the
114     *     {@code Binder} is unable to perform the XML to Java
115     *     binding.
116     * @throws IllegalArgumentException
117     *      If the node parameter is null
118     */
119    public abstract Object unmarshal( XmlNode xmlNode ) throws JAXBException;
120
121    /**
122     * Unmarshal XML root element by provided {@code declaredType}
123     * to a JAXB object tree.
124     *
125     * <p>
126     * Implements <a href="Unmarshaller.html#unmarshalByDeclaredType">Unmarshal by Declared Type</a>
127     *
128     * <p>
129     * This method is similar to {@link Unmarshaller#unmarshal(Node, Class)}
130     * with the addition of maintaining the association between XML nodes
131     * and the produced JAXB objects, enabling future update operations,
132     * {@link #updateXML(Object, Object)} or {@link #updateJAXB(Object)}.
133     *
134     * <p>
135     * When {@link #getSchema()} is non-null, <code>xmlNode</code>
136     * and its descendants is validated during this operation.
137     *
138     * @param xmlNode
139     *      the document/element to unmarshal XML data from.
140     * @param declaredType
141     *      appropriate JAXB mapped class to hold {@code node}'s XML data.
142     *
143     * @return
144     * <a href="JAXBElement.html">JAXB Element</a> representation
145     * of {@code node}
146     *
147     * @throws JAXBException
148     *      If any unexpected errors occur while unmarshalling
149     * @throws UnmarshalException
150     *     If the {@link ValidationEventHandler ValidationEventHandler}
151     *     returns false from its {@code handleEvent} method or the
152     *     {@code Binder} is unable to perform the XML to Java
153     *     binding.
154     * @throws IllegalArgumentException
155     *      If any of the input parameters are null
156     * @since 1.6, JAXB 2.0
157     */
158    public abstract <T> JAXBElement<T>
159        unmarshal( XmlNode xmlNode, Class<T> declaredType )
160        throws JAXBException;
161
162    /**
163     * Marshal a JAXB object tree to a new XML document.
164     *
165     * <p>
166     * This method is similar to {@link Marshaller#marshal(Object, Node)}
167     * with the addition of maintaining the association between JAXB objects
168     * and the produced XML nodes,
169     * enabling future update operations such as
170     * {@link #updateXML(Object, Object)} or {@link #updateJAXB(Object)}.
171     *
172     * <p>
173     * When {@link #getSchema()} is non-null, the marshalled
174     * xml content is validated during this operation.
175     *
176     * @param jaxbObject
177     *      The content tree to be marshalled.
178     * @param xmlNode
179     *      The parameter must be a Node that accepts children.
180     *
181     * @throws JAXBException
182     *      If any unexpected problem occurs during the marshalling.
183     * @throws MarshalException
184     *      If the {@link ValidationEventHandler ValidationEventHandler}
185     *      returns false from its {@code handleEvent} method or the
186     *      {@code Binder} is unable to marshal {@code jaxbObject} (or any
187     *      object reachable from {@code jaxbObject}).
188     *
189     * @throws IllegalArgumentException
190     *      If any of the method parameters are null
191     */
192    public abstract void marshal( Object jaxbObject, XmlNode xmlNode ) throws JAXBException;
193
194    /**
195     * Gets the XML element associated with the given JAXB object.
196     *
197     * <p>
198     * Once a JAXB object tree is associated with an XML fragment,
199     * this method enables navigation between the two trees.
200     *
201     * <p>
202     * An association between an XML element and a JAXB object is
203     * established by the bind methods and the update methods.
204     * Note that this association is partial; not all XML elements
205     * have associated JAXB objects, and not all JAXB objects have
206     * associated XML elements.
207     *
208     * @param jaxbObject An instance that is reachable from a prior
209     *                   call to a bind or update method that returned
210     *                   a JAXB object tree.
211     *
212     * @return
213     *      null if the specified JAXB object is not known to this
214     *      {@link Binder}, or if it is not associated with an
215     *      XML element.
216     *
217     * @throws IllegalArgumentException
218     *      If the jaxbObject parameter is null
219     */
220    public abstract XmlNode getXMLNode( Object jaxbObject );
221
222    /**
223     * Gets the JAXB object associated with the given XML element.
224     *
225     * <p>
226     * Once a JAXB object tree is associated with an XML fragment,
227     * this method enables navigation between the two trees.
228     *
229     * <p>
230     * An association between an XML element and a JAXB object is
231     * established by the unmarshal, marshal and update methods.
232     * Note that this association is partial; not all XML elements
233     * have associated JAXB objects, and not all JAXB objects have
234     * associated XML elements.
235     *
236     * @return
237     *      null if the specified XML node is not known to this
238     *      {@link Binder}, or if it is not associated with a
239     *      JAXB object.
240     *
241     * @throws IllegalArgumentException
242     *      If the node parameter is null
243     */
244    public abstract Object getJAXBNode( XmlNode xmlNode );
245
246    /**
247     * Takes an JAXB object and updates
248     * its associated XML node and its descendants.
249     *
250     * <p>
251     * This is a convenience method of:
252     * <pre>
253     * updateXML( jaxbObject, getXMLNode(jaxbObject));
254     * </pre>
255     *
256     * @throws JAXBException
257     *      If any unexpected problem occurs updating corresponding XML content.
258     * @throws IllegalArgumentException
259     *      If the jaxbObject parameter is null
260     */
261    public abstract XmlNode updateXML( Object jaxbObject ) throws JAXBException;
262
263    /**
264     * Changes in JAXB object tree are updated in its associated XML parse tree.
265     *
266     * <p>
267     * This operation can be thought of as an "in-place" marshalling.
268     * The difference is that instead of creating a whole new XML tree,
269     * this operation updates an existing tree while trying to preserve
270     * the XML as much as possible.
271     *
272     * <p>
273     * For example, unknown elements/attributes in XML that were not bound
274     * to JAXB will be left untouched (whereas a marshalling operation
275     * would create a new tree that doesn't contain any of those.)
276     *
277     * <p>
278     * As a side-effect, this operation updates the association between
279     * XML nodes and JAXB objects.
280     *
281     * @param jaxbObject root of potentially modified JAXB object tree
282     * @param xmlNode    root of update target XML parse tree
283     *
284     * @return
285     *      Returns the updated XML node. Typically, this is the same
286     *      node you passed in as <i>xmlNode</i>, but it maybe
287     *      a different object, for example when the tag name of the object
288     *      has changed.
289     *
290     * @throws JAXBException
291     *      If any unexpected problem occurs updating corresponding XML content.
292     * @throws IllegalArgumentException
293     *      If any of the input parameters are null
294     */
295    public abstract XmlNode updateXML( Object jaxbObject, XmlNode xmlNode ) throws JAXBException;
296
297    /**
298     * Takes an XML node and updates its associated JAXB object and its descendants.
299     *
300     * <p>
301     * This operation can be thought of as an "in-place" unmarshalling.
302     * The difference is that instead of creating a whole new JAXB tree,
303     * this operation updates an existing tree, reusing as much JAXB objects
304     * as possible.
305     *
306     * <p>
307     * As a side-effect, this operation updates the association between
308     * XML nodes and JAXB objects.
309     *
310     * @return
311     *      Returns the updated JAXB object. Typically, this is the same
312     *      object that was returned from earlier
313     *      {@link #marshal(Object,Object)} or
314     *      {@link #updateJAXB(Object)} method invocation,
315     *      but it maybe
316     *      a different object, for example when the name of the XML
317     *      element has changed.
318     *
319     * @throws JAXBException
320     *      If any unexpected problem occurs updating corresponding JAXB mapped content.
321     * @throws IllegalArgumentException
322     *      If node parameter is null
323     */
324    public abstract Object updateJAXB( XmlNode xmlNode ) throws JAXBException;
325
326
327    /**
328     * Specifies whether marshal, unmarshal and update methods
329     * performs validation on their XML content.
330     *
331     * @param schema set to null to disable validation.
332     *
333     * @see Unmarshaller#setSchema(Schema)
334     */
335    public abstract void setSchema( Schema schema );
336
337    /**
338     * Gets the last {@link Schema} object (including null) set by the
339     * {@link #setSchema(Schema)} method.
340     *
341     * @return the Schema object for validation or null if not present
342     */
343    public abstract Schema getSchema();
344
345    /**
346     * Allow an application to register a {@code ValidationEventHandler}.
347     * <p>
348     * The {@code ValidationEventHandler} will be called by the JAXB Provider
349     * if any validation errors are encountered during calls to any of the
350     * Binder unmarshal, marshal and update methods.
351     *
352     * <p>
353     * Calling this method with a null parameter will cause the Binder
354     * to revert back to the default default event handler.
355     *
356     * @param handler the validation event handler
357     * @throws JAXBException if an error was encountered while setting the
358     *         event handler
359     */
360    public abstract void setEventHandler( ValidationEventHandler handler ) throws JAXBException;
361
362    /**
363     * Return the current event handler or the default event handler if one
364     * hasn't been set.
365     *
366     * @return the current ValidationEventHandler or the default event handler
367     *         if it hasn't been set
368     * @throws JAXBException if an error was encountered while getting the
369     *         current event handler
370     */
371    public abstract ValidationEventHandler getEventHandler() throws JAXBException;
372
373    /**
374     *
375     * Set the particular property in the underlying implementation of
376     * {@code Binder}.  This method can only be used to set one of
377     * the standard JAXB defined unmarshal/marshal properties
378     * or a provider specific property for binder, unmarshal or marshal.
379     * Attempting to set an undefined property will result in
380     * a PropertyException being thrown.  See
381     * <a href="Unmarshaller.html#supportedProps">Supported Unmarshal Properties</a>
382     * and
383     * <a href="Marshaller.html#supportedProps">Supported Marshal Properties</a>.
384     *
385     * @param name the name of the property to be set. This value can either
386     *              be specified using one of the constant fields or a user
387     *              supplied string.
388     * @param value the value of the property to be set
389     *
390     * @throws PropertyException when there is an error processing the given
391     *                            property or value
392     * @throws IllegalArgumentException
393     *      If the name parameter is null
394     */
395    abstract public void setProperty( String name, Object value ) throws PropertyException;
396
397
398    /**
399     * Get the particular property in the underlying implementation of
400     * {@code Binder}.  This method can only
401     * be used to get one of
402     * the standard JAXB defined unmarshal/marshal properties
403     * or a provider specific property for binder, unmarshal or marshal.
404     * Attempting to get an undefined property will result in
405     * a PropertyException being thrown.  See
406     * <a href="Unmarshaller.html#supportedProps">Supported Unmarshal Properties</a>
407     * and
408     * <a href="Marshaller.html#supportedProps">Supported Marshal Properties</a>.
409     *
410     * @param name the name of the property to retrieve
411     * @return the value of the requested property
412     *
413     * @throws PropertyException
414     *      when there is an error retrieving the given property or value
415     *      property name
416     * @throws IllegalArgumentException
417     *      If the name parameter is null
418     */
419    abstract public Object getProperty( String name ) throws PropertyException;
420
421}
422