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.controller.sal.rest.impl;
10 import static com.google.common.base.Preconditions.checkArgument;
12 import java.io.BufferedInputStream;
13 import java.io.IOException;
14 import java.io.InputStream;
16 import java.util.Stack;
17 import javax.xml.stream.XMLEventReader;
18 import javax.xml.stream.XMLInputFactory;
19 import javax.xml.stream.XMLStreamConstants;
20 import javax.xml.stream.XMLStreamException;
21 import javax.xml.stream.events.Characters;
22 import javax.xml.stream.events.StartElement;
23 import javax.xml.stream.events.XMLEvent;
24 import org.opendaylight.controller.sal.restconf.impl.CompositeNodeWrapper;
25 import org.opendaylight.controller.sal.restconf.impl.EmptyNodeWrapper;
26 import org.opendaylight.controller.sal.restconf.impl.IdentityValuesDTO;
27 import org.opendaylight.controller.sal.restconf.impl.NodeWrapper;
28 import org.opendaylight.controller.sal.restconf.impl.SimpleNodeWrapper;
29 import org.opendaylight.yangtools.yang.data.api.Node;
31 public class XmlToCompositeNodeReader {
33 private final static XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
34 private XMLEventReader eventReader;
36 public CompositeNodeWrapper read(InputStream entityStream) throws XMLStreamException, UnsupportedFormatException,
38 // Get an XML stream which can be marked, and reset, so we can check and
39 // see if there is any content being provided.
40 entityStream = getMarkableStream(entityStream);
42 if (isInputStreamEmpty(entityStream)) {
46 eventReader = xmlInputFactory.createXMLEventReader(entityStream);
48 if (eventReader.hasNext()) {
49 XMLEvent element = eventReader.peek();
50 if (element.isStartDocument()) {
51 eventReader.nextEvent();
55 if (eventReader.hasNext() && !isCompositeNodeEvent(eventReader.peek())) {
56 throw new UnsupportedFormatException("Root element of XML has to be composite element.");
59 final Stack<NodeWrapper<?>> processingQueue = new Stack<>();
60 CompositeNodeWrapper root = null;
61 NodeWrapper<?> element = null;
62 while (eventReader.hasNext()) {
63 final XMLEvent event = eventReader.nextEvent();
65 if (event.isStartElement()) {
66 final StartElement startElement = event.asStartElement();
67 CompositeNodeWrapper compParentNode = null;
68 if (!processingQueue.isEmpty() && processingQueue.peek() instanceof CompositeNodeWrapper) {
69 compParentNode = (CompositeNodeWrapper) processingQueue.peek();
71 NodeWrapper<?> newNode = null;
72 if (isCompositeNodeEvent(event)) {
74 root = resolveCompositeNodeFromStartElement(startElement);
77 newNode = resolveCompositeNodeFromStartElement(startElement);
79 } else if (isSimpleNodeEvent(event)) {
81 throw new UnsupportedFormatException("Root element of XML has to be composite element.");
83 newNode = resolveSimpleNodeFromStartElement(startElement);
86 if (newNode != null) {
87 processingQueue.push(newNode);
88 if (compParentNode != null) {
89 compParentNode.addValue(newNode);
92 } else if (event.isEndElement()) {
93 element = processingQueue.pop();
97 if (!root.getLocalName().equals(element.getLocalName())) {
98 throw new UnsupportedFormatException("XML should contain only one root element");
105 * If the input stream is not markable, then it wraps the input stream with a buffered stream, which is mark able.
106 * That way we can check if the stream is empty safely.
108 * @param entityStream
111 private InputStream getMarkableStream(InputStream entityStream) {
112 if (!entityStream.markSupported()) {
113 entityStream = new BufferedInputStream(entityStream);
118 private boolean isInputStreamEmpty(InputStream entityStream) throws IOException {
119 boolean isEmpty = false;
120 entityStream.mark(1);
121 if (entityStream.read() == -1) {
124 entityStream.reset();
128 private boolean isSimpleNodeEvent(final XMLEvent event) throws XMLStreamException {
129 checkArgument(event != null, "XML Event cannot be NULL!");
130 if (event.isStartElement()) {
131 XMLEvent innerEvent = skipCommentsAndWhitespace();
132 if (innerEvent != null && (innerEvent.isCharacters() || innerEvent.isEndElement())) {
139 private boolean isCompositeNodeEvent(final XMLEvent event) throws XMLStreamException {
140 checkArgument(event != null, "XML Event cannot be NULL!");
141 if (event.isStartElement()) {
142 XMLEvent innerEvent = skipCommentsAndWhitespace();
143 if (innerEvent != null) {
144 if (innerEvent.isStartElement()) {
152 private XMLEvent skipCommentsAndWhitespace() throws XMLStreamException {
153 while (eventReader.hasNext()) {
154 XMLEvent event = eventReader.peek();
155 if (event.getEventType() == XMLStreamConstants.COMMENT) {
156 eventReader.nextEvent();
160 if (event.isCharacters()) {
161 Characters chars = event.asCharacters();
162 if (chars.isWhiteSpace()) {
163 eventReader.nextEvent();
172 private CompositeNodeWrapper resolveCompositeNodeFromStartElement(final StartElement startElement) {
173 checkArgument(startElement != null, "Start Element cannot be NULL!");
174 return new CompositeNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
177 private NodeWrapper<? extends Node<?>> resolveSimpleNodeFromStartElement(final StartElement startElement)
178 throws XMLStreamException {
179 checkArgument(startElement != null, "Start Element cannot be NULL!");
180 String data = getValueOf(startElement);
182 return new EmptyNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
184 return new SimpleNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement),
185 resolveValueOfElement(data, startElement));
188 private String getValueOf(StartElement startElement) throws XMLStreamException {
190 if (eventReader.hasNext()) {
191 final XMLEvent innerEvent = eventReader.peek();
192 if (innerEvent.isCharacters()) {
193 final Characters chars = innerEvent.asCharacters();
194 if (!chars.isWhiteSpace()) {
195 data = innerEvent.asCharacters().getData();
196 data = data + getAdditionalData(eventReader.nextEvent());
198 } else if (innerEvent.isEndElement()) {
199 if (startElement.getLocation().getCharacterOffset() == innerEvent.getLocation().getCharacterOffset()) {
206 return data == null ? null : data.trim();
209 private String getAdditionalData(XMLEvent event) throws XMLStreamException {
211 if (eventReader.hasNext()) {
212 final XMLEvent innerEvent = eventReader.peek();
213 if (innerEvent.isCharacters() && !innerEvent.isEndElement()) {
214 final Characters chars = innerEvent.asCharacters();
215 if (!chars.isWhiteSpace()) {
216 data = innerEvent.asCharacters().getData();
217 data = data + getAdditionalData(eventReader.nextEvent());
224 private String getLocalNameFor(StartElement startElement) {
225 return startElement.getName().getLocalPart();
228 private URI getNamespaceFor(StartElement startElement) {
229 String namespaceURI = startElement.getName().getNamespaceURI();
230 return namespaceURI.isEmpty() ? null : URI.create(namespaceURI);
233 private Object resolveValueOfElement(String value, StartElement startElement) {
234 // it could be instance-identifier Built-In Type
235 if (value.startsWith("/")) {
236 IdentityValuesDTO iiValue = RestUtil.asInstanceIdentifier(value, new RestUtil.PrefixMapingFromXml(
238 if (iiValue != null) {
242 // it could be identityref Built-In Type
243 String[] namespaceAndValue = value.split(":");
244 if (namespaceAndValue.length == 2) {
245 String namespace = startElement.getNamespaceContext().getNamespaceURI(namespaceAndValue[0]);
246 if (namespace != null && !namespace.isEmpty()) {
247 return new IdentityValuesDTO(namespace, namespaceAndValue[1], namespaceAndValue[0], value);
250 // it is not "prefix:value" but just "value"