ohair@286: /*
ohair@286:  * Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package javax.xml.bind;
ohair@286: 
ohair@286: import javax.xml.bind.annotation.XmlRootElement;
ohair@286: import javax.xml.namespace.QName;
ohair@286: import javax.xml.transform.Result;
ohair@286: import javax.xml.transform.Source;
ohair@286: import javax.xml.transform.stream.StreamResult;
ohair@286: import javax.xml.transform.stream.StreamSource;
ohair@286: import java.beans.Introspector;
ohair@286: import java.io.File;
ohair@286: import java.io.IOException;
ohair@286: import java.io.InputStream;
ohair@286: import java.io.OutputStream;
ohair@286: import java.io.Reader;
ohair@286: import java.io.Writer;
ohair@286: import java.lang.ref.WeakReference;
ohair@286: import java.net.HttpURLConnection;
ohair@286: import java.net.URI;
ohair@286: import java.net.URISyntaxException;
ohair@286: import java.net.URL;
ohair@286: import java.net.URLConnection;
ohair@286: 
ohair@286: /**
ohair@286:  * Class that defines convenience methods for common, simple use of JAXB.
ohair@286:  *
ohair@286:  * <p>
ohair@286:  * Methods defined in this class are convenience methods that combine several basic operations
ohair@286:  * in the {@link JAXBContext}, {@link Unmarshaller}, and {@link Marshaller}.
ohair@286:  *
ohair@286:  * They are designed
ohair@286:  * to be the prefered methods for developers new to JAXB. They have
ohair@286:  * the following characterstics:
ohair@286:  *
ohair@286:  * <ol>
ohair@286:  *  <li>Generally speaking, the performance is not necessarily optimal.
ohair@286:  *      It is expected that people who need to write performance
ohair@286:  *      critical code will use the rest of the JAXB API directly.
ohair@286:  *  <li>Errors that happen during the processing is wrapped into
ohair@286:  *      {@link DataBindingException} (which will have {@link JAXBException}
ohair@286:  *      as its {@link Throwable#getCause() cause}. It is expected that
ohair@286:  *      people who prefer the checked exception would use
ohair@286:  *      the rest of the JAXB API directly.
ohair@286:  * </ol>
ohair@286:  *
ohair@286:  * <p>
ohair@286:  * In addition, the <tt>unmarshal</tt> methods have the following characteristic:
ohair@286:  *
ohair@286:  * <ol>
ohair@286:  *  <li>Schema validation is not performed on the input XML.
ohair@286:  *      The processing will try to continue even if there
ohair@286:  *      are errors in the XML, as much as possible. Only as
ohair@286:  *      the last resort, this method fails with {@link DataBindingException}.
ohair@286:  * </ol>
ohair@286:  *
ohair@286:  * <p>
ohair@286:  * Similarly, the <tt>marshal</tt> methods have the following characteristic:
ohair@286:  * <ol>
ohair@286:  *  <li>The processing will try to continue even if the Java object tree
ohair@286:  *      does not meet the validity requirement. Only as
ohair@286:  *      the last resort, this method fails with {@link DataBindingException}.
ohair@286:  * </ol>
ohair@286:  *
ohair@286:  *
ohair@286:  * <p>
ohair@286:  * All the methods on this class require non-null arguments to all parameters.
ohair@286:  * The <tt>unmarshal</tt> methods either fail with an exception or return
ohair@286:  * a non-null value.
ohair@286:  *
ohair@286:  * @author Kohsuke Kawaguchi
ohair@286:  * @since 2.1
ohair@286:  */
ohair@286: public final class JAXB {
ohair@286:     /**
ohair@286:      * No instanciation is allowed.
ohair@286:      */
ohair@286:     private JAXB() {}
ohair@286: 
ohair@286:     /**
ohair@286:      * To improve the performance, we'll cache the last {@link JAXBContext} used.
ohair@286:      */
ohair@286:     private static final class Cache {
ohair@286:         final Class type;
ohair@286:         final JAXBContext context;
ohair@286: 
ohair@286:         public Cache(Class type) throws JAXBException {
ohair@286:             this.type = type;
ohair@286:             this.context = JAXBContext.newInstance(type);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Cache. We don't want to prevent the {@link Cache#type} from GC-ed,
ohair@286:      * hence {@link WeakReference}.
ohair@286:      */
ohair@286:     private static volatile WeakReference<Cache> cache;
ohair@286: 
ohair@286:     /**
ohair@286:      * Obtains the {@link JAXBContext} from the given type,
ohair@286:      * by using the cache if possible.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * We don't use locks to control access to {@link #cache}, but this code
ohair@286:      * should be thread-safe thanks to the immutable {@link Cache} and {@code volatile}.
ohair@286:      */
ohair@286:     private static <T> JAXBContext getContext(Class<T> type) throws JAXBException {
ohair@286:         WeakReference<Cache> c = cache;
ohair@286:         if(c!=null) {
ohair@286:             Cache d = c.get();
ohair@286:             if(d!=null && d.type==type)
ohair@286:                 return d.context;
ohair@286:         }
ohair@286: 
ohair@286:         // overwrite the cache
ohair@286:         Cache d = new Cache(type);
ohair@286:         cache = new WeakReference<Cache>(d);
ohair@286: 
ohair@286:         return d.context;
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      Reads the entire file as XML.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( File xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(new StreamSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The resource pointed by the URL is read in its entirety.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( URL xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The URI is {@link URI#toURL() turned into URL} and then
ohair@286:      *      follows the handling of <tt>URL</tt>.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( URI xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The string is first interpreted as an absolute <tt>URI</tt>.
ohair@286:      *      If it's not {@link URI#isAbsolute() a valid absolute URI},
ohair@286:      *      then it's interpreted as a <tt>File</tt>
ohair@286:      */
ohair@286:     public static <T> T unmarshal( String xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The entire stream is read as an XML infoset.
ohair@286:      *      Upon a successful completion, the stream will be closed by this method.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( InputStream xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The character stream is read as an XML infoset.
ohair@286:      *      The encoding declaration in the XML will be ignored.
ohair@286:      *      Upon a successful completion, the stream will be closed by this method.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( Reader xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Reads in a Java object tree from the given XML input.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The XML infoset that the {@link Source} represents is read.
ohair@286:      */
ohair@286:     public static <T> T unmarshal( Source xml, Class<T> type ) {
ohair@286:         try {
ohair@286:             JAXBElement<T> item = getContext(type).createUnmarshaller().unmarshal(toSource(xml), type);
ohair@286:             return item.getValue();
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286: 
ohair@286: 
ohair@286:     /**
ohair@286:      * Creates {@link Source} from various XML representation.
ohair@286:      * See {@link #unmarshal} for the conversion rules.
ohair@286:      */
ohair@286:     private static Source toSource(Object xml) throws IOException {
ohair@286:         if(xml==null)
ohair@286:             throw new IllegalArgumentException("no XML is given");
ohair@286: 
ohair@286:         if (xml instanceof String) {
ohair@286:             try {
ohair@286:                 xml=new URI((String)xml);
ohair@286:             } catch (URISyntaxException e) {
ohair@286:                 xml=new File((String)xml);
ohair@286:             }
ohair@286:         }
ohair@286:         if (xml instanceof File) {
ohair@286:             File file = (File) xml;
ohair@286:             return new StreamSource(file);
ohair@286:         }
ohair@286:         if (xml instanceof URI) {
ohair@286:             URI uri = (URI) xml;
ohair@286:             xml=uri.toURL();
ohair@286:         }
ohair@286:         if (xml instanceof URL) {
ohair@286:             URL url = (URL) xml;
ohair@286:             return new StreamSource(url.toExternalForm());
ohair@286:         }
ohair@286:         if (xml instanceof InputStream) {
ohair@286:             InputStream in = (InputStream) xml;
ohair@286:             return new StreamSource(in);
ohair@286:         }
ohair@286:         if (xml instanceof Reader) {
ohair@286:             Reader r = (Reader) xml;
ohair@286:             return new StreamSource(r);
ohair@286:         }
ohair@286:         if (xml instanceof Source) {
ohair@286:             return (Source) xml;
ohair@286:         }
ohair@286:         throw new IllegalArgumentException("I don't understand how to handle "+xml.getClass());
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      XML will be written to this file. If it already exists,
ohair@286:      *      it will be overwritten.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, File xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The XML will be {@link URLConnection#getOutputStream() sent} to the
ohair@286:      *      resource pointed by this URL. Note that not all <tt>URL</tt>s support
ohair@286:      *      such operation, and exact semantics depends on the <tt>URL</tt>
ohair@286:      *      implementations. In case of {@link HttpURLConnection HTTP URLs},
ohair@286:      *      this will perform HTTP POST.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, URL xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The URI is {@link URI#toURL() turned into URL} and then
ohair@286:      *      follows the handling of <tt>URL</tt>. See above.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, URI xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The string is first interpreted as an absolute <tt>URI</tt>.
ohair@286:      *      If it's not {@link URI#isAbsolute() a valid absolute URI},
ohair@286:      *      then it's interpreted as a <tt>File</tt>
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, String xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The XML will be sent to the given {@link OutputStream}.
ohair@286:      *      Upon a successful completion, the stream will be closed by this method.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, OutputStream xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The XML will be sent as a character stream to the given {@link Writer}.
ohair@286:      *      Upon a successful completion, the stream will be closed by this method.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, Writer xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      The XML will be sent to the {@link Result} object.
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     public static void marshal( Object jaxbObject, Result xml ) {
ohair@286:         _marshal(jaxbObject,xml);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Writes a Java object tree to XML and store it to the specified location.
ohair@286:      *
ohair@286:      * <p>
ohair@286:      * This method is a convenience method that combines several basic operations
ohair@286:      * in the {@link JAXBContext} and {@link Marshaller}. This method is designed
ohair@286:      * to be the prefered method for developers new to JAXB. This method
ohair@286:      * has the following characterstics:
ohair@286:      *
ohair@286:      * <ol>
ohair@286:      *  <li>Generally speaking, the performance is not necessarily optimal.
ohair@286:      *      It is expected that those people who need to write performance
ohair@286:      *      critical code will use the rest of the JAXB API directly.
ohair@286:      *  <li>Errors that happen during the processing is wrapped into
ohair@286:      *      {@link DataBindingException} (which will have {@link JAXBException}
ohair@286:      *      as its {@link Throwable#getCause() cause}. It is expected that
ohair@286:      *      those people who prefer the checked exception would use
ohair@286:      *      the rest of the JAXB API directly.
ohair@286:      * </ol>
ohair@286:      *
ohair@286:      * @param jaxbObject
ohair@286:      *      The Java object to be marshalled into XML. If this object is
ohair@286:      *      a {@link JAXBElement}, it will provide the root tag name and
ohair@286:      *      the body. If this object has {@link XmlRootElement}
ohair@286:      *      on its class definition, that will be used as the root tag name
ohair@286:      *      and the given object will provide the body. Otherwise,
ohair@286:      *      the root tag name is {@link Introspector#decapitalize(String) infered} from
ohair@286:      *      {@link Class#getSimpleName() the short class name}.
ohair@286:      *      This parameter must not be null.
ohair@286:      *
ohair@286:      * @param xml
ohair@286:      *      Represents the receiver of XML. Objects of the following types are allowed.
ohair@286:      *
ohair@286:      *      <table><tr>
ohair@286:      *          <th>Type</th>
ohair@286:      *          <th>Operation</th>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link File}</td>
ohair@286:      *          <td>XML will be written to this file. If it already exists,
ohair@286:      *              it will be overwritten.</td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link URL}</td>
ohair@286:      *          <td>The XML will be {@link URLConnection#getOutputStream() sent} to the
ohair@286:      *              resource pointed by this URL. Note that not all <tt>URL</tt>s support
ohair@286:      *              such operation, and exact semantics depends on the <tt>URL</tt>
ohair@286:      *              implementations. In case of {@link HttpURLConnection HTTP URLs},
ohair@286:      *              this will perform HTTP POST.</td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link URI}</td>
ohair@286:      *          <td>The URI is {@link URI#toURL() turned into URL} and then
ohair@286:      *              follows the handling of <tt>URL</tt>. See above.</td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link String}</td>
ohair@286:      *          <td>The string is first interpreted as an absolute <tt>URI</tt>.
ohair@286:      *              If it's not {@link URI#isAbsolute() a valid absolute URI},
ohair@286:      *              then it's interpreted as a <tt>File</tt></td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link OutputStream}</td>
ohair@286:      *          <td>The XML will be sent to the given {@link OutputStream}.
ohair@286:      *              Upon a successful completion, the stream will be closed by this method.</td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link Writer}</td>
ohair@286:      *          <td>The XML will be sent as a character stream to the given {@link Writer}.
ohair@286:      *              Upon a successful completion, the stream will be closed by this method.</td>
ohair@286:      *      </tr><tr>
ohair@286:      *          <td>{@link Result}</td>
ohair@286:      *          <td>The XML will be sent to the {@link Result} object.</td>
ohair@286:      *      </tr></table>
ohair@286:      *
ohair@286:      * @throws DataBindingException
ohair@286:      *      If the operation fails, such as due to I/O error, unbindable classes.
ohair@286:      */
ohair@286:     private static void _marshal( Object jaxbObject, Object xml ) {
ohair@286:         try {
ohair@286:             JAXBContext context;
ohair@286: 
ohair@286:             if(jaxbObject instanceof JAXBElement) {
ohair@286:                 context = getContext(((JAXBElement<?>)jaxbObject).getDeclaredType());
ohair@286:             } else {
ohair@286:                 Class<?> clazz = jaxbObject.getClass();
ohair@286:                 XmlRootElement r = clazz.getAnnotation(XmlRootElement.class);
ohair@286:                 context = getContext(clazz);
ohair@286:                 if(r==null) {
ohair@286:                     // we need to infer the name
ohair@286:                     jaxbObject = new JAXBElement(new QName(inferName(clazz)),clazz,jaxbObject);
ohair@286:                 }
ohair@286:             }
ohair@286: 
ohair@286:             Marshaller m = context.createMarshaller();
ohair@286:             m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,true);
ohair@286:             m.marshal(jaxbObject, toResult(xml));
ohair@286:         } catch (JAXBException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         } catch (IOException e) {
ohair@286:             throw new DataBindingException(e);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     private static String inferName(Class clazz) {
ohair@286:         return Introspector.decapitalize(clazz.getSimpleName());
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Creates {@link Result} from various XML representation.
ohair@286:      * See {@link #_marshal(Object,Object)} for the conversion rules.
ohair@286:      */
ohair@286:     private static Result toResult(Object xml) throws IOException {
ohair@286:         if(xml==null)
ohair@286:             throw new IllegalArgumentException("no XML is given");
ohair@286: 
ohair@286:         if (xml instanceof String) {
ohair@286:             try {
ohair@286:                 xml=new URI((String)xml);
ohair@286:             } catch (URISyntaxException e) {
ohair@286:                 xml=new File((String)xml);
ohair@286:             }
ohair@286:         }
ohair@286:         if (xml instanceof File) {
ohair@286:             File file = (File) xml;
ohair@286:             return new StreamResult(file);
ohair@286:         }
ohair@286:         if (xml instanceof URI) {
ohair@286:             URI uri = (URI) xml;
ohair@286:             xml=uri.toURL();
ohair@286:         }
ohair@286:         if (xml instanceof URL) {
ohair@286:             URL url = (URL) xml;
ohair@286:             URLConnection con = url.openConnection();
ohair@286:             con.setDoOutput(true);
ohair@286:             con.setDoInput(false);
ohair@286:             con.connect();
ohair@286:             return new StreamResult(con.getOutputStream());
ohair@286:         }
ohair@286:         if (xml instanceof OutputStream) {
ohair@286:             OutputStream os = (OutputStream) xml;
ohair@286:             return new StreamResult(os);
ohair@286:         }
ohair@286:         if (xml instanceof Writer) {
ohair@286:             Writer w = (Writer)xml;
ohair@286:             return new StreamResult(w);
ohair@286:         }
ohair@286:         if (xml instanceof Result) {
ohair@286:             return (Result) xml;
ohair@286:         }
ohair@286:         throw new IllegalArgumentException("I don't understand how to handle "+xml.getClass());
ohair@286:     }
ohair@286: 
ohair@286: }