/*
* Copyright 2002-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.oxm.support;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.stax.StAXSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.w3c.dom.Node;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.XMLReaderFactory;
import org.springframework.oxm.Marshaller;
import org.springframework.oxm.Unmarshaller;
import org.springframework.oxm.UnmarshallingFailureException;
import org.springframework.oxm.XmlMappingException;
import org.springframework.util.Assert;
import org.springframework.util.xml.StaxUtils;
/**
* Abstract implementation of the <code>Marshaller</code> and <code>Unmarshaller</code> interface.
* This implementation inspects the given <code>Source</code> or <code>Result</code>, and defers
* further handling to overridable template methods.
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
*/
public abstract class AbstractMarshaller implements Marshaller, Unmarshaller {
/** Logger available to subclasses. */
protected final Log logger = LogFactory.getLog(getClass());
private DocumentBuilderFactory documentBuilderFactory;
private final Object documentBuilderFactoryMonitor = new Object();
/**
* Marshals the object graph with the given root into the provided <code>javax.xml.transform.Result</code>.
* <p>This implementation inspects the given result, and calls <code>marshalDomResult</code>,
* <code>marshalSaxResult</code>, or <code>marshalStreamResult</code>.
* @param graph the root of the object graph to marshal
* @param result the result to marshal to
* @throws IOException if an I/O exception occurs
* @throws XmlMappingException if the given object cannot be marshalled to the result
* @throws IllegalArgumentException if <code>result</code> if neither a <code>DOMResult</code>,
* a <code>SAXResult</code>, nor a <code>StreamResult</code>
* @see #marshalDomResult(Object, javax.xml.transform.dom.DOMResult)
* @see #marshalSaxResult(Object, javax.xml.transform.sax.SAXResult)
* @see #marshalStreamResult(Object, javax.xml.transform.stream.StreamResult)
*/
public final void marshal(Object graph, Result result) throws IOException, XmlMappingException {
if (result instanceof DOMResult) {
marshalDomResult(graph, (DOMResult) result);
}
else if (StaxUtils.isStaxResult(result)) {
marshalStaxResult(graph, result);
}
else if (result instanceof SAXResult) {
marshalSaxResult(graph, (SAXResult) result);
}
else if (result instanceof StreamResult) {
marshalStreamResult(graph, (StreamResult) result);
}
else {
throw new IllegalArgumentException("Unknown Result type: " + result.getClass());
}
}
/**
* Unmarshals the given provided <code>javax.xml.transform.Source</code> into an object graph.
* <p>This implementation inspects the given result, and calls <code>unmarshalDomSource</code>,
* <code>unmarshalSaxSource</code>, or <code>unmarshalStreamSource</code>.
* @param source the source to marshal from
* @return the object graph
* @throws IOException if an I/O Exception occurs
* @throws XmlMappingException if the given source cannot be mapped to an object
* @throws IllegalArgumentException if <code>source</code> is neither a <code>DOMSource</code>,
* a <code>SAXSource</code>, nor a <code>StreamSource</code>
* @see #unmarshalDomSource(javax.xml.transform.dom.DOMSource)
* @see #unmarshalSaxSource(javax.xml.transform.sax.SAXSource)
* @see #unmarshalStreamSource(javax.xml.transform.stream.StreamSource)
*/
public final Object unmarshal(Source source) throws IOException, XmlMappingException {
if (source instanceof DOMSource) {
return unmarshalDomSource((DOMSource) source);
}
else if (StaxUtils.isStaxSource(source)) {
return unmarshalStaxSource(source);
}
else if (source instanceof SAXSource) {
return unmarshalSaxSource((SAXSource) source);
}
else if (source instanceof StreamSource) {
return unmarshalStreamSource((StreamSource) source);
}
else {
throw new IllegalArgumentException("Unknown Source type: " + source.getClass());
}
}
/**
* Create a <code>DocumentBuilder</code> that this marshaller will use for creating
* DOM documents when passed an empty <code>DOMSource</code>.
* <p>Can be overridden in subclasses, adding further initialization of the builder.
* @param factory the <code>DocumentBuilderFactory</code> that the DocumentBuilder should be created with
* @return the <code>DocumentBuilder</code>
* @throws ParserConfigurationException if thrown by JAXP methods
*/
protected DocumentBuilder createDocumentBuilder(DocumentBuilderFactory factory)
throws ParserConfigurationException {
return factory.newDocumentBuilder();
}
/**
* Create a <code>DocumentBuilder</code> that this marshaller will use for creating
* DOM documents when passed an empty <code>DOMSource</code>.
* <p>The resulting <code>DocumentBuilderFactory</code> is cached, so this method
* will only be called once.
* @return the DocumentBuilderFactory
* @throws ParserConfigurationException if thrown by JAXP methods
*/
protected DocumentBuilderFactory createDocumentBuilderFactory() throws ParserConfigurationException {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(false);
factory.setNamespaceAware(true);
return factory;
}
/**
* Create a <code>XMLReader</code> that this marshaller will when passed an empty <code>SAXSource</code>.
* @return the XMLReader
* @throws SAXException if thrown by JAXP methods
*/
protected XMLReader createXmlReader() throws SAXException {
return XMLReaderFactory.createXMLReader();
}
// Marshalling
/**
* Template method for handling <code>DOMResult</code>s.
* <p>This implementation delegates to <code>marshalDomNode</code>.
* @param graph the root of the object graph to marshal
* @param domResult the <code>DOMResult</code>
* @throws XmlMappingException if the given object cannot be marshalled to the result
* @throws IllegalArgumentException if the <code>domResult</code> is empty
* @see #marshalDomNode(Object, org.w3c.dom.Node)
*/
protected void marshalDomResult(Object graph, DOMResult domResult) throws XmlMappingException {
if (domResult.getNode() == null) {
try {
synchronized (this.documentBuilderFactoryMonitor) {
if (this.documentBuilderFactory == null) {
this.documentBuilderFactory = createDocumentBuilderFactory();
}
}
DocumentBuilder documentBuilder = createDocumentBuilder(this.documentBuilderFactory);
domResult.setNode(documentBuilder.newDocument());
}
catch (ParserConfigurationException ex) {
throw new UnmarshallingFailureException(
"Could not create document placeholder for DOMResult: " + ex.getMessage(), ex);
}
}
marshalDomNode(graph, domResult.getNode());
}
/**
* Template method for handling <code>StaxResult</code>s.
* <p>This implementation delegates to <code>marshalXMLSteamWriter</code> or
* <code>marshalXMLEventConsumer</code>, depending on what is contained in the
* <code>StaxResult</code>.
* @param graph the root of the object graph to marshal
* @param staxResult a Spring {@link org.springframework.util.xml.StaxSource} or JAXP 1.4 {@link StAXSource}
* @throws XmlMappingException if the given object cannot be marshalled to the result
* @throws IllegalArgumentException if the <code>domResult</code> is empty
* @see #marshalDomNode(Object,org.w3c.dom.Node)
*/
protected void marshalStaxResult(Object graph, Result staxResult) throws XmlMappingException {
XMLStreamWriter streamWriter = StaxUtils.getXMLStreamWriter(staxResult);
if (streamWriter != null) {
marshalXmlStreamWriter(graph, streamWriter);
}
else {
XMLEventWriter eventWriter = StaxUtils.getXMLEventWriter(staxResult);
if (eventWriter != null) {
marshalXmlEventWriter(graph, eventWriter);
}
else {
throw new IllegalArgumentException("StaxResult contains neither XMLStreamWriter nor XMLEventConsumer");
}
}
}
/**
* Template method for handling <code>SAXResult</code>s.
* <p>This implementation delegates to <code>marshalSaxHandlers</code>.
* @param graph the root of the object graph to marshal
* @param saxResult the <code>SAXResult</code>
* @throws XmlMappingException if the given object cannot be marshalled to the result
* @see #marshalSaxHandlers(Object, org.xml.sax.ContentHandler, org.xml.sax.ext.LexicalHandler)
*/
protected void marshalSaxResult(Object graph, SAXResult saxResult) throws XmlMappingException {
ContentHandler contentHandler = saxResult.getHandler();
Assert.notNull(contentHandler, "ContentHandler not set on SAXResult");
LexicalHandler lexicalHandler = saxResult.getLexicalHandler();
marshalSaxHandlers(graph, contentHandler, lexicalHandler);
}
/**
* Template method for handling <code>StreamResult</code>s.
* <p>This implementation delegates to <code>marshalOutputStream</code> or <code>marshalWriter</code>,
* depending on what is contained in the <code>StreamResult</code>
* @param graph the root of the object graph to marshal
* @param streamResult the <code>StreamResult</code>
* @throws IOException if an I/O Exception occurs
* @throws XmlMappingException if the given object cannot be marshalled to the result
* @throws IllegalArgumentException if <code>streamResult</code> does neither
* contain an <code>OutputStream</code> nor a <code>Writer</code>
*/
protected void marshalStreamResult(Object graph, StreamResult streamResult)
throws XmlMappingException, IOException {
if (streamResult.getOutputStream() != null) {
marshalOutputStream(graph, streamResult.getOutputStream());
}
else if (streamResult.getWriter() != null) {
marshalWriter(graph, streamResult.getWriter());
}
else {
throw new IllegalArgumentException("StreamResult contains neither OutputStream nor Writer");
}
}
// Unmarshalling
/**
* Template method for handling <code>DOMSource</code>s.
* <p>This implementation delegates to <code>unmarshalDomNode</code>.
* If the given source is empty, an empty source <code>Document</code>
* will be created as a placeholder.
* @param domSource the <code>DOMSource</code>
* @return the object graph
* @throws XmlMappingException if the given source cannot be mapped to an object
* @throws IllegalArgumentException if the <code>domSource</code> is empty
* @see #unmarshalDomNode(org.w3c.dom.Node)
*/
protected Object unmarshalDomSource(DOMSource domSource) throws XmlMappingException {
if (domSource.getNode() == null) {
try {
synchronized (this.documentBuilderFactoryMonitor) {
if (this.documentBuilderFactory == null) {
this.documentBuilderFactory = createDocumentBuilderFactory();
}
}
DocumentBuilder documentBuilder = createDocumentBuilder(this.documentBuilderFactory);
domSource.setNode(documentBuilder.newDocument());
}
catch (ParserConfigurationException ex) {
throw new UnmarshallingFailureException(
"Could not create document placeholder for DOMSource: " + ex.getMessage(), ex);
}
}
return unmarshalDomNode(domSource.getNode());
}
/**
* Template method for handling <code>StaxSource</code>s.
* <p>This implementation delegates to <code>unmarshalXmlStreamReader</code> or
* <code>unmarshalXmlEventReader</code>.
* @param staxSource the <code>StaxSource</code>
* @return the object graph
* @throws XmlMappingException if the given source cannot be mapped to an object
*/
protected Object unmarshalStaxSource(Source staxSource) throws XmlMappingException {
XMLStreamReader streamReader = StaxUtils.getXMLStreamReader(staxSource);
if (streamReader != null) {
return unmarshalXmlStreamReader(streamReader);
}
else {
XMLEventReader eventReader = StaxUtils.getXMLEventReader(staxSource);
if (eventReader != null) {
return unmarshalXmlEventReader(eventReader);
}
else {
throw new IllegalArgumentException("StaxSource contains neither XMLStreamReader nor XMLEventReader");
}
}
}
/**
* Template method for handling <code>SAXSource</code>s.
* <p>This implementation delegates to <code>unmarshalSaxReader</code>.
* @param saxSource the <code>SAXSource</code>
* @return the object graph
* @throws XmlMappingException if the given source cannot be mapped to an object
* @throws IOException if an I/O Exception occurs
* @see #unmarshalSaxReader(org.xml.sax.XMLReader, org.xml.sax.InputSource)
*/
protected Object unmarshalSaxSource(SAXSource saxSource) throws XmlMappingException, IOException {
if (saxSource.getXMLReader() == null) {
try {
saxSource.setXMLReader(createXmlReader());
}
catch (SAXException ex) {
throw new UnmarshallingFailureException("Could not create XMLReader for SAXSource", ex);
}
}
if (saxSource.getInputSource() == null) {
saxSource.setInputSource(new InputSource());
}
return unmarshalSaxReader(saxSource.getXMLReader(), saxSource.getInputSource());
}
/**
* Template method for handling <code>StreamSource</code>s.
* <p>This implementation defers to <code>unmarshalInputStream</code> or <code>unmarshalReader</code>.
* @param streamSource the <code>StreamSource</code>
* @return the object graph
* @throws IOException if an I/O exception occurs
* @throws XmlMappingException if the given source cannot be mapped to an object
*/
protected Object unmarshalStreamSource(StreamSource streamSource) throws XmlMappingException, IOException {
if (streamSource.getInputStream() != null) {
return unmarshalInputStream(streamSource.getInputStream());
}
else if (streamSource.getReader() != null) {
return unmarshalReader(streamSource.getReader());
}
else {
throw new IllegalArgumentException("StreamSource contains neither InputStream nor Reader");
}
}
// Abstract template methods
/**
* Abstract template method for marshalling the given object graph to a DOM <code>Node</code>.
* <p>In practice, node is be a <code>Document</code> node, a <code>DocumentFragment</code> node,
* or a <code>Element</code> node. In other words, a node that accepts children.
* @param graph the root of the object graph to marshal
* @param node the DOM node that will contain the result tree
* @throws XmlMappingException if the given object cannot be marshalled to the DOM node
* @see org.w3c.dom.Document
* @see org.w3c.dom.DocumentFragment
* @see org.w3c.dom.Element
*/
protected abstract void marshalDomNode(Object graph, Node node)
throws XmlMappingException;
/**
* Abstract template method for marshalling the given object to a StAX <code>XMLEventWriter</code>.
* @param graph the root of the object graph to marshal
* @param eventWriter the <code>XMLEventWriter</code> to write to
* @throws XmlMappingException if the given object cannot be marshalled to the DOM node
*/
protected abstract void marshalXmlEventWriter(Object graph, XMLEventWriter eventWriter)
throws XmlMappingException;
/**
* Abstract template method for marshalling the given object to a StAX <code>XMLStreamWriter</code>.
* @param graph the root of the object graph to marshal
* @param streamWriter the <code>XMLStreamWriter</code> to write to
* @throws XmlMappingException if the given object cannot be marshalled to the DOM node
*/
protected abstract void marshalXmlStreamWriter(Object graph, XMLStreamWriter streamWriter)
throws XmlMappingException;
/**
* Abstract template method for marshalling the given object graph to a <code>OutputStream</code>.
* @param graph the root of the object graph to marshal
* @param outputStream the <code>OutputStream</code> to write to
* @throws XmlMappingException if the given object cannot be marshalled to the writer
* @throws IOException if an I/O exception occurs
*/
protected abstract void marshalOutputStream(Object graph, OutputStream outputStream)
throws XmlMappingException, IOException;
/**
* Abstract template method for marshalling the given object graph to a SAX <code>ContentHandler</code>.
* @param graph the root of the object graph to marshal
* @param contentHandler the SAX <code>ContentHandler</code>
* @param lexicalHandler the SAX2 <code>LexicalHandler</code>. Can be <code>null</code>.
* @throws XmlMappingException if the given object cannot be marshalled to the handlers
*/
protected abstract void marshalSaxHandlers(
Object graph, ContentHandler contentHandler, LexicalHandler lexicalHandler)
throws XmlMappingException;
/**
* Abstract template method for marshalling the given object graph to a <code>Writer</code>.
* @param graph the root of the object graph to marshal
* @param writer the <code>Writer</code> to write to
* @throws XmlMappingException if the given object cannot be marshalled to the writer
* @throws IOException if an I/O exception occurs
*/
protected abstract void marshalWriter(Object graph, Writer writer)
throws XmlMappingException, IOException;
/**
* Abstract template method for unmarshalling from a given DOM <code>Node</code>.
* @param node the DOM node that contains the objects to be unmarshalled
* @return the object graph
* @throws XmlMappingException if the given DOM node cannot be mapped to an object
*/
protected abstract Object unmarshalDomNode(Node node) throws XmlMappingException;
/**
* Abstract template method for unmarshalling from a given Stax <code>XMLEventReader</code>.
* @param eventReader the <code>XMLEventReader</code> to read from
* @return the object graph
* @throws XmlMappingException if the given event reader cannot be converted to an object
*/
protected abstract Object unmarshalXmlEventReader(XMLEventReader eventReader)
throws XmlMappingException;
/**
* Abstract template method for unmarshalling from a given Stax <code>XMLStreamReader</code>.
* @param streamReader the <code>XMLStreamReader</code> to read from
* @return the object graph
* @throws XmlMappingException if the given stream reader cannot be converted to an object
*/
protected abstract Object unmarshalXmlStreamReader(XMLStreamReader streamReader)
throws XmlMappingException;
/**
* Abstract template method for unmarshalling from a given <code>InputStream</code>.
* @param inputStream the <code>InputStreamStream</code> to read from
* @return the object graph
* @throws XmlMappingException if the given stream cannot be converted to an object
* @throws IOException if an I/O exception occurs
*/
protected abstract Object unmarshalInputStream(InputStream inputStream)
throws XmlMappingException, IOException;
/**
* Abstract template method for unmarshalling from a given <code>Reader</code>.
* @param reader the <code>Reader</code> to read from
* @return the object graph
* @throws XmlMappingException if the given reader cannot be converted to an object
* @throws IOException if an I/O exception occurs
*/
protected abstract Object unmarshalReader(Reader reader)
throws XmlMappingException, IOException;
/**
* Abstract template method for unmarshalling using a given SAX <code>XMLReader</code>
* and <code>InputSource</code>.
* @param xmlReader the SAX <code>XMLReader</code> to parse with
* @param inputSource the input source to parse from
* @return the object graph
* @throws XmlMappingException if the given reader and input source cannot be converted to an object
* @throws IOException if an I/O exception occurs
*/
protected abstract Object unmarshalSaxReader(XMLReader xmlReader, InputSource inputSource)
throws XmlMappingException, IOException;
}
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