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;
32 public class XmlToCompositeNodeReader {
34 private final static XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
36 xmlInputFactory.setProperty("javax.xml.stream.isSupportingExternalEntities", false);
38 private XMLEventReader eventReader;
40 public Node<?> read(InputStream entityStream) throws XMLStreamException,
41 UnsupportedFormatException,
43 //Get an XML stream which can be marked, and reset, so we can check and see if there is
44 //any content being provided.
45 entityStream = getMarkableStream(entityStream);
47 if (isInputStreamEmpty(entityStream)) {
51 eventReader = xmlInputFactory.createXMLEventReader(entityStream);
52 if (eventReader.hasNext()) {
53 XMLEvent element = eventReader.peek();
54 if (element.isStartDocument()) {
55 eventReader.nextEvent();
59 final Stack<NodeWrapper<?>> processingQueue = new Stack<>();
60 NodeWrapper<?> 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)) {
73 newNode = resolveCompositeNodeFromStartElement(startElement);
77 } else if (isSimpleNodeEvent(event)) {
78 newNode = resolveSimpleNodeFromStartElement(startElement);
84 if (newNode != null) {
85 processingQueue.push(newNode);
86 if (compParentNode != null) {
87 compParentNode.addValue(newNode);
90 } else if (event.isEndElement()) {
91 element = processingQueue.pop();
95 if (!root.getLocalName().equals(element.getLocalName())) {
96 throw new UnsupportedFormatException("XML should contain only one root element");
99 return (Node<?>) root;
103 * If the input stream is not markable, then it wraps the input stream with a buffered stream, which is mark able.
104 * That way we can check if the stream is empty safely.
106 * @param entityStream
109 private InputStream getMarkableStream(InputStream entityStream) {
110 if (!entityStream.markSupported()) {
111 entityStream = new BufferedInputStream(entityStream);
116 private boolean isInputStreamEmpty(final InputStream entityStream) throws IOException {
117 boolean isEmpty = false;
118 entityStream.mark(1);
119 if (entityStream.read() == -1) {
122 entityStream.reset();
126 private boolean isSimpleNodeEvent(final XMLEvent event) throws XMLStreamException {
127 checkArgument(event != null, "XML Event cannot be NULL!");
128 if (event.isStartElement()) {
129 XMLEvent innerEvent = skipCommentsAndWhitespace();
130 if (innerEvent != null && (innerEvent.isCharacters() || innerEvent.isEndElement())) {
137 private boolean isCompositeNodeEvent(final XMLEvent event) throws XMLStreamException {
138 checkArgument(event != null, "XML Event cannot be NULL!");
139 if (event.isStartElement()) {
140 XMLEvent innerEvent = skipCommentsAndWhitespace();
141 if (innerEvent != null) {
142 if (innerEvent.isStartElement()) {
150 private XMLEvent skipCommentsAndWhitespace() throws XMLStreamException {
151 while (eventReader.hasNext()) {
152 XMLEvent event = eventReader.peek();
153 if (event.getEventType() == XMLStreamConstants.COMMENT) {
154 eventReader.nextEvent();
158 if (event.isCharacters()) {
159 Characters chars = event.asCharacters();
160 if (chars.isWhiteSpace()) {
161 eventReader.nextEvent();
170 private CompositeNodeWrapper resolveCompositeNodeFromStartElement(final StartElement startElement) {
171 checkArgument(startElement != null, "Start Element cannot be NULL!");
172 return new CompositeNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
175 private NodeWrapper<? extends Node<?>> resolveSimpleNodeFromStartElement(final StartElement startElement)
176 throws XMLStreamException {
177 checkArgument(startElement != null, "Start Element cannot be NULL!");
178 String data = getValueOf(startElement);
180 return new EmptyNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement));
182 return new SimpleNodeWrapper(getNamespaceFor(startElement), getLocalNameFor(startElement),
183 resolveValueOfElement(data, startElement));
186 private String getValueOf(final StartElement startElement) throws XMLStreamException {
188 if (eventReader.hasNext()) {
189 final XMLEvent innerEvent = eventReader.peek();
190 if (innerEvent.isCharacters()) {
191 final Characters chars = innerEvent.asCharacters();
192 if (!chars.isWhiteSpace()) {
193 data = innerEvent.asCharacters().getData();
194 data = data + getAdditionalData(eventReader.nextEvent());
196 } else if (innerEvent.isEndElement()) {
197 if (startElement.getLocation().getCharacterOffset() == innerEvent.getLocation().getCharacterOffset()) {
204 return data == null ? null : data.trim();
207 private String getAdditionalData(final XMLEvent event) throws XMLStreamException {
209 if (eventReader.hasNext()) {
210 final XMLEvent innerEvent = eventReader.peek();
211 if (innerEvent.isCharacters() && !innerEvent.isEndElement()) {
212 final Characters chars = innerEvent.asCharacters();
213 if (!chars.isWhiteSpace()) {
214 data = innerEvent.asCharacters().getData();
215 data = data + getAdditionalData(eventReader.nextEvent());
222 private String getLocalNameFor(final StartElement startElement) {
223 return startElement.getName().getLocalPart();
226 private URI getNamespaceFor(final StartElement startElement) {
227 String namespaceURI = startElement.getName().getNamespaceURI();
228 return namespaceURI.isEmpty() ? null : URI.create(namespaceURI);
231 private Object resolveValueOfElement(final String value, final StartElement startElement) {
232 // it could be instance-identifier Built-In Type
233 if (value.startsWith("/")) {
234 IdentityValuesDTO iiValue = RestUtil.asInstanceIdentifier(value, new RestUtil.PrefixMapingFromXml(
236 if (iiValue != null) {
240 // it could be identityref Built-In Type
241 String[] namespaceAndValue = value.split(":");
242 if (namespaceAndValue.length == 2) {
243 String namespace = startElement.getNamespaceContext().getNamespaceURI(namespaceAndValue[0]);
244 if (namespace != null && !namespace.isEmpty()) {
245 return new IdentityValuesDTO(namespace, namespaceAndValue[1], namespaceAndValue[0], value);
248 // it is not "prefix:value" but just "value"