Added StaxStreamContentHandler

org.springframework.core/src/main/java/org/springframework/util/xml/AbstractStaxContentHandler.java

@@ -0,0 +1,167 @@
+/*
+ * Copyright 2002-2009 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.util.xml;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+
+import org.xml.sax.Attributes;
+import org.xml.sax.ContentHandler;
+import org.xml.sax.SAXException;
+
+/**
+ * Abstract base class for SAX <code>ContentHandler</code> implementations that use StAX as a basis. All methods
+ * delegate to internal template methods, capable of throwing a <code>XMLStreamException</code>. Additionally, an
+ * namespace context is used to keep track of declared namespaces.
+ *
+ * @author Arjen Poutsma
+ * @since 3.0
+ */
+abstract class AbstractStaxContentHandler implements ContentHandler {
+
+	private SimpleNamespaceContext namespaceContext = new SimpleNamespaceContext();
+
+	public final void startDocument() throws SAXException {
+		namespaceContext.clear();
+		try {
+			startDocumentInternal();
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle startDocument: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void startDocumentInternal() throws XMLStreamException;
+
+	public final void endDocument() throws SAXException {
+		namespaceContext.clear();
+		try {
+			endDocumentInternal();
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle startDocument: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void endDocumentInternal() throws XMLStreamException;
+
+	/**
+	 * Binds the given prefix to the given namespaces.
+	 *
+	 * @see SimpleNamespaceContext#bindNamespaceUri(String,String)
+	 */
+	public final void startPrefixMapping(String prefix, String uri) {
+		namespaceContext.bindNamespaceUri(prefix, uri);
+	}
+
+	/**
+	 * Removes the binding for the given prefix.
+	 *
+	 * @see SimpleNamespaceContext#removeBinding(String)
+	 */
+	public final void endPrefixMapping(String prefix) {
+		namespaceContext.removeBinding(prefix);
+	}
+
+	public final void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
+		try {
+			startElementInternal(toQName(uri, qName), atts, namespaceContext);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle startElement: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void startElementInternal(QName name, Attributes atts, SimpleNamespaceContext namespaceContext)
+			throws XMLStreamException;
+
+	public final void endElement(String uri, String localName, String qName) throws SAXException {
+		try {
+			endElementInternal(toQName(uri, qName), namespaceContext);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle endElement: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void endElementInternal(QName name, SimpleNamespaceContext namespaceContext)
+			throws XMLStreamException;
+
+	public final void characters(char ch[], int start, int length) throws SAXException {
+		try {
+			charactersInternal(ch, start, length);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle characters: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void charactersInternal(char[] ch, int start, int length) throws XMLStreamException;
+
+	public final void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
+		try {
+			ignorableWhitespaceInternal(ch, start, length);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle ignorableWhitespace:" + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void ignorableWhitespaceInternal(char[] ch, int start, int length) throws XMLStreamException;
+
+	public final void processingInstruction(String target, String data) throws SAXException {
+		try {
+			processingInstructionInternal(target, data);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle processingInstruction: " + ex.getMessage(), ex);
+		}
+	}
+
+	protected abstract void processingInstructionInternal(String target, String data) throws XMLStreamException;
+
+	public final void skippedEntity(String name) throws SAXException {
+		try {
+			skippedEntityInternal(name);
+		}
+		catch (XMLStreamException ex) {
+			throw new SAXException("Could not handle skippedEntity: " + ex.getMessage(), ex);
+		}
+	}
+
+	/**
+	 * Convert a namespace URI and DOM or SAX qualified name to a <code>QName</code>. The qualified name can have the form
+	 * <code>prefix:localname</code> or <code>localName</code>.
+	 *
+	 * @param namespaceUri  the namespace URI
+	 * @param qualifiedName the qualified name
+	 * @return a QName
+	 */
+	protected QName toQName(String namespaceUri, String qualifiedName) {
+		int idx = qualifiedName.indexOf(':');
+		if (idx == -1) {
+			return new QName(namespaceUri, qualifiedName);
+		}
+		else {
+			String prefix = qualifiedName.substring(0, idx);
+			String localPart = qualifiedName.substring(idx + 1);
+			return new QName(namespaceUri, localPart, prefix);
+		}
+	}
+
+	protected abstract void skippedEntityInternal(String name) throws XMLStreamException;
+}

org.springframework.core/src/main/java/org/springframework/util/xml/StaxStreamContentHandler.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2002-2009 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.util.xml;
+
+import java.util.Iterator;
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.xml.sax.Attributes;
+import org.xml.sax.Locator;
+
+import org.springframework.util.StringUtils;
+
+/**
+ * SAX <code>ContentHandler</code> that writes to a <code>XMLStreamWriter</code>.
+ *
+ * @author Arjen Poutsma
+ * @see XMLStreamWriter
+ * @since 3.0
+ */
+class StaxStreamContentHandler extends AbstractStaxContentHandler {
+
+	private final XMLStreamWriter streamWriter;
+
+	/**
+	 * Constructs a new instance of the <code>StaxStreamContentHandler</code> that writes to the given
+	 * <code>XMLStreamWriter</code>.
+	 *
+	 * @param streamWriter the stream writer to write to
+	 */
+	StaxStreamContentHandler(XMLStreamWriter streamWriter) {
+		this.streamWriter = streamWriter;
+	}
+
+	public void setDocumentLocator(Locator locator) {
+	}
+
+	@Override
+	protected void charactersInternal(char[] ch, int start, int length) throws XMLStreamException {
+		streamWriter.writeCharacters(ch, start, length);
+	}
+
+	@Override
+	protected void endDocumentInternal() throws XMLStreamException {
+		streamWriter.writeEndDocument();
+	}
+
+	@Override
+	protected void endElementInternal(QName name, SimpleNamespaceContext namespaceContext) throws XMLStreamException {
+		streamWriter.writeEndElement();
+	}
+
+	@Override
+	protected void ignorableWhitespaceInternal(char[] ch, int start, int length) throws XMLStreamException {
+		streamWriter.writeCharacters(ch, start, length);
+	}
+
+	@Override
+	protected void processingInstructionInternal(String target, String data) throws XMLStreamException {
+		streamWriter.writeProcessingInstruction(target, data);
+	}
+
+	@Override
+	protected void skippedEntityInternal(String name) {
+	}
+
+	@Override
+	protected void startDocumentInternal() throws XMLStreamException {
+		streamWriter.writeStartDocument();
+	}
+
+	@Override
+	protected void startElementInternal(QName name, Attributes attributes, SimpleNamespaceContext namespaceContext)
+			throws XMLStreamException {
+		streamWriter.writeStartElement(name.getPrefix(), name.getLocalPart(), name.getNamespaceURI());
+		String defaultNamespaceUri = namespaceContext.getNamespaceURI("");
+		if (StringUtils.hasLength(defaultNamespaceUri)) {
+			streamWriter.writeNamespace("", defaultNamespaceUri);
+			streamWriter.setDefaultNamespace(defaultNamespaceUri);
+		}
+		for (Iterator iterator = namespaceContext.getBoundPrefixes(); iterator.hasNext();) {
+			String prefix = (String) iterator.next();
+			streamWriter.writeNamespace(prefix, namespaceContext.getNamespaceURI(prefix));
+			streamWriter.setPrefix(prefix, namespaceContext.getNamespaceURI(prefix));
+		}
+		for (int i = 0; i < attributes.getLength(); i++) {
+			QName attrName = toQName(attributes.getURI(i), attributes.getQName(i));
+			if (!("xmlns".equals(attrName.getLocalPart()) || "xmlns".equals(attrName.getPrefix()))) {
+				streamWriter.writeAttribute(attrName.getPrefix(), attrName.getNamespaceURI(), attrName.getLocalPart(),
+						attributes.getValue(i));
+			}
+		}
+	}
+}

org.springframework.core/src/test/java/org/springframework/util/xml/AbstractStaxContentHandlerTestCase.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2009 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.util.xml;
+
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.io.Writer;
+import javax.xml.stream.XMLStreamException;
+
+import static org.custommonkey.xmlunit.XMLAssert.assertXMLEqual;
+import org.junit.Before;
+import org.junit.Test;
+import org.xml.sax.InputSource;
+import org.xml.sax.XMLReader;
+import org.xml.sax.helpers.XMLReaderFactory;
+
+public abstract class AbstractStaxContentHandlerTestCase {
+
+	private static final String XML_CONTENT_HANDLER =
+			"<?xml version='1.0' encoding='UTF-8'?><?pi content?><root xmlns='namespace'><prefix:child xmlns:prefix='namespace2' prefix:attr='value'>content</prefix:child></root>"
+			;
+
+	private XMLReader xmlReader;
+
+	@Before
+	public void createXMLReader() throws Exception {
+		xmlReader = XMLReaderFactory.createXMLReader();
+	}
+
+	@Test
+	public void contentHandler() throws Exception {
+		StringWriter stringWriter = new StringWriter();
+		AbstractStaxContentHandler handler = createStaxContentHandler(stringWriter);
+		xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", false);
+		xmlReader.setContentHandler(handler);
+		xmlReader.parse(new InputSource(new StringReader(XML_CONTENT_HANDLER)));
+		assertXMLEqual("Invalid result", XML_CONTENT_HANDLER, stringWriter.toString());
+	}
+
+	@Test
+	public void contentHandlerNamespacePrefixes() throws Exception {
+		StringWriter stringWriter = new StringWriter();
+		AbstractStaxContentHandler handler = createStaxContentHandler(stringWriter);
+		xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
+		xmlReader.setContentHandler(handler);
+		xmlReader.parse(new InputSource(new StringReader(XML_CONTENT_HANDLER)));
+		assertXMLEqual("Invalid result", XML_CONTENT_HANDLER, stringWriter.toString());
+	}
+
+	protected abstract AbstractStaxContentHandler createStaxContentHandler(Writer writer) throws XMLStreamException;
+
+}

org.springframework.core/src/test/java/org/springframework/util/xml/StaxStreamContentHandlerTest.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-2009 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.util.xml;
+
+import java.io.Writer;
+import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamException;
+
+public class StaxStreamContentHandlerTest extends AbstractStaxContentHandlerTestCase {
+
+	@Override
+	protected AbstractStaxContentHandler createStaxContentHandler(Writer writer) throws XMLStreamException {
+		XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
+		return new StaxStreamContentHandler(outputFactory.createXMLStreamWriter(writer));
+	}
+}