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 Node<?> read(InputStream entityStream) throws XMLStreamException,
37 UnsupportedFormatException,
39 //Get an XML stream which can be marked, and reset, so we can check and see if there is
40 //any content being provided.
41 entityStream = getMarkableStream(entityStream);
43 if (isInputStreamEmpty(entityStream)) {
47 eventReader = xmlInputFactory.createXMLEventReader(entityStream);
49 if (eventReader.hasNext()) {
50 XMLEvent element = eventReader.peek();
51 if (element.isStartDocument()) {
52 eventReader.nextEvent();
56 final Stack<NodeWrapper<?>> processingQueue = new Stack<>();
57 NodeWrapper<?> root = null;
58 NodeWrapper<?> element = null;
59 while (eventReader.hasNext()) {
60 final XMLEvent event = eventReader.nextEvent();
62 if (event.isStartElement()) {
63 final StartElement startElement = event.asStartElement();
64 CompositeNodeWrapper compParentNode = null;
65 if (!processingQueue.isEmpty() && processingQueue.peek() instanceof CompositeNodeWrapper) {
66 compParentNode = (CompositeNodeWrapper) processingQueue.peek();
68 NodeWrapper<?> newNode = null;
69 if (isCompositeNodeEvent(event)) {
70 newNode = resolveCompositeNodeFromStartElement(startElement);
74 } else if (isSimpleNodeEvent(event)) {
75 newNode = resolveSimpleNodeFromStartElement(startElement);
81 if (newNode != null) {
82 processingQueue.push(newNode);
83 if (compParentNode != null) {
84 compParentNode.addValue(newNode);
87 } else if (event.isEndElement()) {
88 element = processingQueue.pop();
92 if (!root.getLocalName().equals(element.getLocalName())) {
93 throw new UnsupportedFormatException("XML should contain only one root element");
96 return (Node<?>) root;
100 * If the input stream is not markable, then it wraps the input stream with a buffered stream, which is mark able.
101 * That way we can check if the stream is empty safely.
103 * @param entityStream
106 private InputStream getMarkableStream(InputStream entityStream) {
107 if (!entityStream.markSupported()) {
108 entityStream = new BufferedInputStream(entityStream);
113 private boolean isInputStreamEmpty(InputStream entityStream) throws IOException {
114 boolean isEmpty = false;
115 entityStream.mark(1);
116 if (entityStream.read() == -1) {
119 entityStream.reset();
123 private boolean isSimpleNodeEvent(final XMLEvent event) throws XMLStreamException {
124 checkArgument(event != null, "XML Event cannot be NULL!");
125 if (event.isStartElement()) {
126 XMLEvent innerEvent = skipCommentsAndWhitespace();
127 if (innerEvent != null && (innerEvent.isCharacters() || innerEvent.isEndElement())) {
134 private boolean isCompositeNodeEvent(final XMLEvent event) throws XMLStreamException {
135 checkArgument(event != null, "XML Event cannot be NULL!");
136 if (event.isStartElement()) {
137 XMLEvent innerEvent = skipCommentsAndWhitespace();
138 if (innerEvent != null) {
139 if (innerEvent.isStartElement()) {
147 private XMLEvent skipCommentsAndWhitespace() throws XMLStreamException {
148 while (eventReader.hasNext()) {
149 XMLEvent event = eventReader.peek();
150 if (event.getEventType() == XMLStreamConstants.COMMENT) {
151 eventReader.nextEvent();
155 if (event.isCharacters()) {
156 Characters chars = event.asCharacters();
157 if (chars.isWhiteSpace()) {
158 eventReader.nextEvent();
167 private CompositeNodeWrapper resolveCompositeNodeFromStartElement(final StartElement startElement) {
168 checkArgument(startElement != null, "Start Element cannot be NULL!");
169 return new CompositeNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
172 private NodeWrapper<? extends Node<?>> resolveSimpleNodeFromStartElement(final StartElement startElement)
173 throws XMLStreamException {
174 checkArgument(startElement != null, "Start Element cannot be NULL!");
175 String data = getValueOf(startElement);
177 return new EmptyNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
179 return new SimpleNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement),
180 resolveValueOfElement(data, startElement));
183 private String getValueOf(StartElement startElement) throws XMLStreamException {
185 if (eventReader.hasNext()) {
186 final XMLEvent innerEvent = eventReader.peek();
187 if (innerEvent.isCharacters()) {
188 final Characters chars = innerEvent.asCharacters();
189 if (!chars.isWhiteSpace()) {
190 data = innerEvent.asCharacters().getData();
191 data = data + getAdditionalData(eventReader.nextEvent());
193 } else if (innerEvent.isEndElement()) {
194 if (startElement.getLocation().getCharacterOffset() == innerEvent.getLocation().getCharacterOffset()) {
201 return data == null ? null : data.trim();
204 private String getAdditionalData(XMLEvent event) throws XMLStreamException {
206 if (eventReader.hasNext()) {
207 final XMLEvent innerEvent = eventReader.peek();
208 if (innerEvent.isCharacters() && !innerEvent.isEndElement()) {
209 final Characters chars = innerEvent.asCharacters();
210 if (!chars.isWhiteSpace()) {
211 data = innerEvent.asCharacters().getData();
212 data = data + getAdditionalData(eventReader.nextEvent());
219 private String getLocalNameFor(StartElement startElement) {
220 return startElement.getName().getLocalPart();
223 private URI getNamespaceFor(StartElement startElement) {
224 String namespaceURI = startElement.getName().getNamespaceURI();
225 return namespaceURI.isEmpty() ? null : URI.create(namespaceURI);
228 private Object resolveValueOfElement(String value, StartElement startElement) {
229 // it could be instance-identifier Built-In Type
230 if (value.startsWith("/")) {
231 IdentityValuesDTO iiValue = RestUtil.asInstanceIdentifier(value, new RestUtil.PrefixMapingFromXml(
233 if (iiValue != null) {
237 // it could be identityref Built-In Type
238 String[] namespaceAndValue = value.split(":");
239 if (namespaceAndValue.length == 2) {
240 String namespace = startElement.getNamespaceContext().getNamespaceURI(namespaceAndValue[0]);
241 if (namespace != null && !namespace.isEmpty()) {
242 return new IdentityValuesDTO(namespace, namespaceAndValue[1], namespaceAndValue[0], value);
245 // it is not "prefix:value" but just "value"