2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.data.codec.xml;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static java.util.Objects.requireNonNull;
13 import com.google.common.base.Strings;
14 import java.io.IOException;
15 import java.io.StringWriter;
18 import java.util.Map.Entry;
20 import java.util.concurrent.ConcurrentHashMap;
21 import javax.xml.XMLConstants;
22 import javax.xml.namespace.NamespaceContext;
23 import javax.xml.stream.XMLStreamConstants;
24 import javax.xml.stream.XMLStreamException;
25 import javax.xml.stream.XMLStreamWriter;
26 import javax.xml.transform.OutputKeys;
27 import javax.xml.transform.Transformer;
28 import javax.xml.transform.TransformerException;
29 import javax.xml.transform.TransformerFactory;
30 import javax.xml.transform.dom.DOMSource;
31 import javax.xml.transform.stream.StreamResult;
32 import org.eclipse.jdt.annotation.NonNull;
33 import org.eclipse.jdt.annotation.Nullable;
34 import org.opendaylight.yangtools.yang.common.QName;
35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
36 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
37 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
38 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamAttributeWriter;
39 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
40 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
41 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
42 import org.slf4j.Logger;
43 import org.slf4j.LoggerFactory;
44 import org.w3c.dom.Element;
45 import org.w3c.dom.Node;
48 * A {@link NormalizedNodeStreamWriter} which translates the events into an {@link XMLStreamWriter},
49 * resulting in a RFC 6020 XML encoding. There are 2 versions of this class, one that takes a
50 * SchemaContext and encodes values appropriately according to the yang schema. The other is
51 * schema-less and merely outputs values using toString. The latter is intended for debugging
52 * where doesn't have a SchemaContext available and isn't meant for production use.
54 public abstract class XMLStreamNormalizedNodeStreamWriter<T> implements NormalizedNodeStreamAttributeWriter {
55 private static final Logger LOG = LoggerFactory.getLogger(XMLStreamNormalizedNodeStreamWriter.class);
56 private static final TransformerFactory TRANSFORMER_FACTORY = TransformerFactory.newInstance();
57 private static final Set<String> BROKEN_NAMESPACES = ConcurrentHashMap.newKeySet();
59 private final @NonNull XMLStreamWriter writer;
60 private final RandomPrefix prefixes;
62 XMLStreamNormalizedNodeStreamWriter(final XMLStreamWriter writer) {
63 this.writer = requireNonNull(writer);
64 this.prefixes = new RandomPrefix(writer.getNamespaceContext());
68 * Create a new writer with the specified context as its root.
70 * @param writer Output {@link XMLStreamWriter}
71 * @param context Associated {@link SchemaContext}.
72 * @return A new {@link NormalizedNodeStreamWriter}
74 public static NormalizedNodeStreamWriter create(final XMLStreamWriter writer, final SchemaContext context) {
75 return create(writer, context, SchemaPath.ROOT);
79 * Create a new writer with the specified context and rooted in the specified schema path.
81 * @param writer Output {@link XMLStreamWriter}
82 * @param context Associated {@link SchemaContext}.
85 * @return A new {@link NormalizedNodeStreamWriter}
87 public static @NonNull NormalizedNodeStreamWriter create(final XMLStreamWriter writer, final SchemaContext context,
88 final SchemaPath path) {
89 return new SchemaAwareXMLStreamNormalizedNodeStreamWriter(writer, context, path);
93 * Create a new schema-less writer. Note that this version is intended for debugging
94 * where doesn't have a SchemaContext available and isn't meant for production use.
96 * @param writer Output {@link XMLStreamWriter}
98 * @return A new {@link NormalizedNodeStreamWriter}
100 public static @NonNull NormalizedNodeStreamWriter createSchemaless(final XMLStreamWriter writer) {
101 return new SchemalessXMLStreamNormalizedNodeStreamWriter(writer);
104 abstract void writeValue(@NonNull XMLStreamWriter xmlWriter, QName qname, @NonNull Object value, T context)
105 throws IOException, XMLStreamException;
107 abstract void startList(NodeIdentifier name);
109 abstract void startListItem(PathArgument name) throws IOException;
111 private void writeAttributes(final @NonNull Map<QName, String> attributes) throws IOException {
112 for (final Entry<QName, String> entry : attributes.entrySet()) {
114 final QName qname = entry.getKey();
115 final String namespace = qname.getNamespace().toString();
117 if (!Strings.isNullOrEmpty(namespace)) {
118 final String prefix = getPrefix(qname.getNamespace(), namespace);
119 writer.writeAttribute(prefix, namespace, qname.getLocalName(), entry.getValue());
121 writer.writeAttribute(qname.getLocalName(), entry.getValue());
123 } catch (final XMLStreamException e) {
124 throw new IOException("Unable to emit attribute " + entry, e);
129 private String getPrefix(final URI uri, final String str) throws XMLStreamException {
130 final String prefix = writer.getPrefix(str);
131 if (prefix != null) {
135 // This is needed to recover from attributes emitted while the namespace was not declared. Ordinarily
136 // attribute namespaces would be bound in the writer, so the resulting XML is efficient, but we cannot rely
137 // on that having been done.
138 if (BROKEN_NAMESPACES.add(str)) {
139 LOG.info("Namespace {} was not bound, please fix the caller", str, new Throwable());
142 return prefixes.encodePrefix(uri);
145 private void writeStartElement(final QName qname) throws XMLStreamException {
146 final String ns = qname.getNamespace().toString();
147 final NamespaceContext context = writer.getNamespaceContext();
148 final boolean needDefaultNs;
149 if (context != null) {
150 final String parentNs = context.getNamespaceURI(XMLConstants.DEFAULT_NS_PREFIX);
151 needDefaultNs = !ns.equals(parentNs);
153 needDefaultNs = false;
156 writer.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX, qname.getLocalName(), ns);
158 writer.writeDefaultNamespace(ns);
162 final void writeElement(final QName qname, final Object value, final @Nullable Map<QName, String> attributes,
163 final T context) throws IOException {
165 writeStartElement(qname);
166 if (attributes != null) {
167 writeAttributes(attributes);
170 writeValue(writer, qname, value, context);
172 writer.writeEndElement();
173 } catch (XMLStreamException e) {
174 throw new IOException("Failed to emit element", e);
178 final void startElement(final QName qname) throws IOException {
180 writeStartElement(qname);
181 } catch (XMLStreamException e) {
182 throw new IOException("Failed to start element", e);
186 final void endElement() throws IOException {
188 writer.writeEndElement();
189 } catch (XMLStreamException e) {
190 throw new IOException("Failed to end element", e);
194 final void anyxmlNode(final QName qname, final Object value) throws IOException {
196 checkArgument(value instanceof DOMSource, "AnyXML value must be DOMSource, not %s", value);
197 final DOMSource domSource = (DOMSource) value;
198 final Node domNode = requireNonNull(domSource.getNode());
199 checkArgument(domNode.getNodeName().equals(qname.getLocalName()));
200 checkArgument(domNode.getNamespaceURI().equals(qname.getNamespace().toString()));
203 writeStreamReader(new DOMSourceXMLStreamReader(domSource));
204 } catch (XMLStreamException e) {
205 throw new IOException("Unable to transform anyXml(" + qname + ") value: " + domNode, e);
210 private void writeStreamReader(final DOMSourceXMLStreamReader reader) throws XMLStreamException {
211 while (reader.hasNext()) {
212 final int event = reader.next();
214 case XMLStreamConstants.START_ELEMENT:
215 forwardStartElement(reader);
217 case XMLStreamConstants.END_ELEMENT:
218 writer.writeEndElement();
220 case XMLStreamConstants.PROCESSING_INSTRUCTION:
221 forwardProcessingInstruction(reader);
223 case XMLStreamConstants.CHARACTERS:
224 writer.writeCharacters(reader.getText());
226 case XMLStreamConstants.COMMENT:
227 writer.writeComment(reader.getText());
229 case XMLStreamConstants.SPACE:
230 // Ignore insignificant whitespace
232 case XMLStreamConstants.START_DOCUMENT:
233 case XMLStreamConstants.END_DOCUMENT:
234 // We are embedded: ignore start/end document events
236 case XMLStreamConstants.ENTITY_REFERENCE:
237 writer.writeEntityRef(reader.getLocalName());
239 case XMLStreamConstants.ATTRIBUTE:
240 forwardAttributes(reader);
242 case XMLStreamConstants.DTD:
243 writer.writeDTD(reader.getText());
245 case XMLStreamConstants.CDATA:
246 writer.writeCData(reader.getText());
248 case XMLStreamConstants.NAMESPACE:
249 forwardNamespaces(reader);
251 case XMLStreamConstants.NOTATION_DECLARATION:
252 case XMLStreamConstants.ENTITY_DECLARATION:
254 throw new IllegalStateException("Unhandled event " + event);
259 private void forwardAttributes(final DOMSourceXMLStreamReader reader) throws XMLStreamException {
260 for (int i = 0; i < reader.getAttributeCount(); ++i) {
261 final String localName = reader.getAttributeLocalName(i);
262 final String value = reader.getAttributeValue(i);
263 final String prefix = reader.getAttributePrefix(i);
264 if (prefix != null) {
265 writer.writeAttribute(prefix, reader.getAttributeNamespace(i), localName, value);
267 writer.writeAttribute(localName, value);
272 private void forwardNamespaces(final DOMSourceXMLStreamReader reader) throws XMLStreamException {
273 for (int i = 0; i < reader.getNamespaceCount(); ++i) {
274 writer.writeNamespace(reader.getNamespacePrefix(i), reader.getNamespaceURI(i));
278 private void forwardProcessingInstruction(final DOMSourceXMLStreamReader reader) throws XMLStreamException {
279 final String target = reader.getPITarget();
280 final String data = reader.getPIData();
282 writer.writeProcessingInstruction(target, data);
284 writer.writeProcessingInstruction(target);
288 private void forwardStartElement(final DOMSourceXMLStreamReader reader) throws XMLStreamException {
289 final String localName = reader.getLocalName();
290 final String prefix = reader.getPrefix();
291 if (prefix != null) {
292 writer.writeStartElement(prefix, localName, reader.getNamespaceURI());
294 writer.writeStartElement(localName);
297 forwardNamespaces(reader);
298 forwardAttributes(reader);
302 public final void startContainerNode(final NodeIdentifier name, final int childSizeHint,
303 final Map<QName, String> attributes) throws IOException {
304 startContainerNode(name, childSizeHint);
305 writeAttributes(attributes);
309 public final void startYangModeledAnyXmlNode(final NodeIdentifier name, final int childSizeHint,
310 final Map<QName, String> attributes) throws IOException {
311 startYangModeledAnyXmlNode(name, childSizeHint);
312 writeAttributes(attributes);
316 public final void startUnkeyedListItem(final NodeIdentifier name, final int childSizeHint,
317 final Map<QName, String> attributes) throws IOException {
318 startUnkeyedListItem(name, childSizeHint);
319 writeAttributes(attributes);
323 public final void startUnkeyedListItem(final NodeIdentifier name, final int childSizeHint) throws IOException {
328 public final void startMapEntryNode(final NodeIdentifierWithPredicates identifier, final int childSizeHint,
329 final Map<QName, String> attributes) throws IOException {
330 startMapEntryNode(identifier, childSizeHint);
331 writeAttributes(attributes);
335 public final void startMapEntryNode(final NodeIdentifierWithPredicates identifier, final int childSizeHint)
337 startListItem(identifier);
341 public final void startUnkeyedList(final NodeIdentifier name, final int childSizeHint) {
346 public final void startMapNode(final NodeIdentifier name, final int childSizeHint) {
351 public final void startOrderedMapNode(final NodeIdentifier name, final int childSizeHint) {
355 public static String toString(final Element xml) {
357 final Transformer transformer = TRANSFORMER_FACTORY.newTransformer();
358 transformer.setOutputProperty(OutputKeys.INDENT, "yes");
360 final StreamResult result = new StreamResult(new StringWriter());
361 transformer.transform(new DOMSource(xml), result);
363 return result.getWriter().toString();
364 } catch (IllegalArgumentException | TransformerException e) {
365 throw new IllegalStateException("Unable to serialize xml element " + xml, e);
370 public final void close() throws IOException {
373 } catch (XMLStreamException e) {
374 throw new IOException("Failed to close writer", e);
379 public final void flush() throws IOException {
382 } catch (XMLStreamException e) {
383 throw new IOException("Failed to flush writer", e);