bpmn/MSOCoreBPMN/src/main/java/org/openecomp/mso/bpmn/core/xml/XmlTool.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * OPENECOMP - MSO
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20
  21 package org.openecomp.mso.bpmn.core.xml;
  22
  23 import java.io.FileNotFoundException;
  24 import java.io.IOException;
  25 import java.io.InputStream;
  26 import java.io.InputStreamReader;
  27 import java.io.Reader;
  28 import java.io.StringReader;
  29 import java.io.StringWriter;
  30 import java.util.HashMap;
  31 import java.util.Map;
  32
  33 import javax.xml.parsers.DocumentBuilder;
  34 import javax.xml.parsers.DocumentBuilderFactory;
  35 import javax.xml.parsers.ParserConfigurationException;
  36 import javax.xml.transform.OutputKeys;
  37 import javax.xml.transform.Source;
  38 import javax.xml.transform.Transformer;
  39 import javax.xml.transform.TransformerException;
  40 import javax.xml.transform.TransformerFactory;
  41 import javax.xml.transform.dom.DOMSource;
  42 import javax.xml.transform.stream.StreamResult;
  43 import javax.xml.transform.stream.StreamSource;
  44 import javax.xml.xpath.XPath;
  45 import javax.xml.xpath.XPathConstants;
  46 import javax.xml.xpath.XPathExpressionException;
  47 import javax.xml.xpath.XPathFactory;
  48
  49 import org.w3c.dom.Document;
  50 import org.w3c.dom.Node;
  51 import org.w3c.dom.NodeList;
  52 import org.xml.sax.InputSource;
  53 import org.xml.sax.SAXException;
  54
  55 /**
  56  * XML transformation methods and other useful functions.
  57  */
  58 public final class XmlTool {
  59
  60         private static final Map<String, Integer> ENTITIES = new HashMap<String, Integer>();
  61
  62         static {
  63                 ENTITIES.put("amp", new Integer(38));
  64                 ENTITIES.put("quot", new Integer(34));
  65                 ENTITIES.put("lt", new Integer(60));
  66                 ENTITIES.put("gt", new Integer(62));
  67         }
  68
  69         /**
  70          * Normalizes and formats XML.  This method consolidates and moves all namespace
  71          * declarations to the root element.  The result will not have an XML prolog or
  72          * a trailing newline.
  73          * @param xml the XML to normalize
  74          * @throws IOException
  75          * @throws TransformerException
  76          * @throws ParserConfigurationException
  77          * @throws SAXException
  78          * @throws XPathExpressionException
  79          */
  80         public static String normalize(Object xml) throws IOException, TransformerException,
  81                         ParserConfigurationException, SAXException, XPathExpressionException {
  82
  83                 if (xml == null) {
  84                         return null;
  85                 }
  86
  87                 Source xsltSource = new StreamSource(new StringReader(
  88                         readResourceFile("normalize-namespaces.xsl")));
  89
  90                 DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
  91                 dbFactory.setNamespaceAware(true);
  92                 DocumentBuilder db = dbFactory.newDocumentBuilder();
  93                 InputSource source = new InputSource(new StringReader(String.valueOf(xml)));
  94                 Document doc = db.parse(source);
  95
  96                 // Start of code to remove whitespace outside of tags
  97                 XPath xPath = XPathFactory.newInstance().newXPath();
  98                 NodeList nodeList = (NodeList) xPath.evaluate(
  99                         "//text()[normalize-space()='']", doc, XPathConstants.NODESET);
 100
 101                 for (int i = 0; i < nodeList.getLength(); ++i) {
 102                         Node node = nodeList.item(i);
 103                         node.getParentNode().removeChild(node);
 104                 }
 105                 // End of code to remove whitespace outside of tags
 106
 107                 // the factory pattern supports different XSLT processors
 108                 TransformerFactory transformerFactory = TransformerFactory.newInstance();
 109                 Transformer transformer = transformerFactory.newTransformer(xsltSource);
 110
 111                 transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 112                 transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
 113                 transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 114                 transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
 115
 116                 StringWriter writer = new StringWriter();
 117                 transformer.transform(new DOMSource(doc), new StreamResult(writer));
 118                 return writer.toString().trim();
 119         }
 120
 121         /**
 122          * Encodes a value so it can be used inside an XML text element.
 123          * @param s the string to encode
 124          * @return the encoded string
 125          */
 126         public static String encode(Object value) {
 127                 if (value == null) {
 128                         return null;
 129                 }
 130
 131                 String s = String.valueOf(value);
 132                 StringBuilder out = new StringBuilder();
 133                 boolean modified = false;
 134
 135                 for (int i = 0; i < s.length(); i++) {
 136                         char c = s.charAt(i);
 137
 138                         if (c == '<') {
 139                                 out.append("&lt;");
 140                                 modified = true;
 141                         } else if (c == '>') {
 142                                 out.append("&gt;");
 143                                 modified = true;
 144                         } else if (c == '&') {
 145                                 out.append("&amp;");
 146                                 modified = true;
 147                         } else if (c < 32 || c > 126) {
 148                                 out.append("&#" + (int)c + ";");
 149                                 modified = true;
 150                         } else {
 151                                 out.append(c);
 152                         }
 153                 }
 154
 155                 if (modified) {
 156                         return out.toString();
 157                 } else {
 158                         return s;
 159                 }
 160         }
 161
 162         /**
 163          * Encodes a value so it can be used inside an XML attribute.
 164          * @param s the string to encode
 165          * @return the encoded string
 166          */
 167         public static String encodeAttr(Object value) {
 168                 if (value == null) {
 169                         return null;
 170                 }
 171
 172                 String s = String.valueOf(value);
 173                 StringBuilder out = new StringBuilder();
 174                 boolean modified = false;
 175
 176                 for (int i = 0; i < s.length(); i++) {
 177                         char c = s.charAt(i);
 178
 179                         if (c == '<') {
 180                                 out.append("&lt;");
 181                                 modified = true;
 182                         } else if (c == '>') {
 183                                 out.append("&gt;");
 184                                 modified = true;
 185                         } else if (c == '"') {
 186                                 out.append("&quot;");
 187                                 modified = true;
 188                         } else if (c == '&') {
 189                                 out.append("&amp;");
 190                                 modified = true;
 191                         } else if (c < 32 || c > 126) {
 192                                 out.append("&#" + (int)c + ";");
 193                                 modified = true;
 194                         } else {
 195                                 out.append(c);
 196                         }
 197                 }
 198
 199                 if (modified) {
 200                         return out.toString();
 201                 } else {
 202                         return s;
 203                 }
 204         }
 205
 206         /**
 207          * Decodes XML entities in a string value
 208          * @param value a value with embedded XML entities
 209          * @return the decoded string
 210          */
 211         public static String decode(Object value) {
 212                 if (value == null) {
 213                         return null;
 214                 }
 215
 216                 String s = String.valueOf(value);
 217
 218                 StringBuilder out = new StringBuilder(s.length());
 219                 int ampIndex = s.indexOf("&");
 220                 int lastEnd = 0;
 221
 222                 while (ampIndex >= 0) {
 223                         int nextAmpIndex = s.indexOf("&", ampIndex + 1);
 224                         int nextSemiIndex = s.indexOf(";", ampIndex + 1);
 225                         if (nextSemiIndex != -1 && (nextAmpIndex == -1 || nextSemiIndex < nextAmpIndex)) {
 226                                 int code = -1;
 227                                 String entity = s.substring(ampIndex + 1, nextSemiIndex);
 228
 229                                 try {
 230                                         if (entity.startsWith("#")) {
 231                                                 code = Integer.parseInt(entity.substring(1), 10);
 232                                         } else {
 233                                                 if (ENTITIES.containsKey(entity)) {
 234                                                         code = ENTITIES.get(entity);
 235                                                 }
 236                                         }
 237                                 } catch (NumberFormatException x) {
 238                                         // Do nothing
 239                                 }
 240
 241                                 out.append(s.substring(lastEnd, ampIndex));
 242                                 lastEnd = nextSemiIndex + 1;
 243                                 if (code >= 0 && code <= 0xffff) {
 244                                         out.append((char) code);
 245                                 } else {
 246                                         out.append("&");
 247                                         out.append(entity);
 248                                         out.append(";");
 249                                 }
 250                         }
 251
 252                         ampIndex = nextAmpIndex;
 253                 }
 254
 255                 out.append(s.substring(lastEnd));
 256                 return out.toString();
 257         }
 258
 259         /**
 260          * Removes the preamble, if present, from an XML document.
 261          * @param xml the XML document
 262          * @return a possibly modified document
 263          */
 264         public static String removePreamble(Object xml) {
 265                 if (xml == null) {
 266                         return null;
 267                 }
 268
 269                 return String.valueOf(xml).replaceAll("(<\\?[^<]*\\?>\\s*[\\r\\n]*)?", "");
 270         }
 271
 272         /**
 273          * Removes namespaces and namespace declarations from an XML document.
 274          * @param xml the XML document
 275          * @return a possibly modified document
 276          */
 277         public static String removeNamespaces(Object xml) {
 278                 if (xml == null) {
 279                         return null;
 280                 }
 281
 282                 String text = String.valueOf(xml);
 283
 284                 // remove xmlns declaration
 285                 text = text.replaceAll("xmlns.*?(\"|\').*?(\"|\')", "");
 286                 // remove opening tag prefix
 287                 text = text.replaceAll("(<)(\\w+:)(.*?>)", "$1$3");
 288                 // remove closing tags prefix
 289                 text = text.replaceAll("(</)(\\w+:)(.*?>)", "$1$3");
 290                 // remove extra spaces left when xmlns declarations are removed
 291                 text = text.replaceAll("\\s+>", ">");
 292
 293                 return text;
 294         }
 295
 296
 297         /**
 298          * Reads the specified resource file and return the contents as a string.
 299          * @param file Name of the resource file
 300          * @return the contents of the resource file as a String
 301          * @throws IOException if there is a problem reading the file
 302          */
 303         private static String readResourceFile(String file) throws IOException {
 304                 InputStream stream = null;
 305                 try {
 306                         stream = XmlTool.class.getClassLoader().getResourceAsStream(file);
 307
 308                         if (stream == null) {
 309                                 throw new FileNotFoundException("No such resource file: " + file);
 310                         }
 311
 312                         Reader reader = new InputStreamReader(stream, "UTF-8");
 313                         StringBuilder out = new StringBuilder();
 314                         char[] buf = new char[1024];
 315                         int n;
 316
 317                         while ((n = reader.read(buf)) >= 0) {
 318                                 out.append(buf, 0, n);
 319                         }
 320
 321                         stream.close();
 322                         stream = null;
 323                         return out.toString();
 324                 } finally {
 325                         if (stream != null) {
 326                                 try {
 327                                         stream.close();
 328                                 } catch (Exception e) {
 329                                         // Ignore
 330                                 }
 331                         }
 332                 }
 333         }
 334
 335         /**
 336          * Instantiation is not allowed.
 337          */
 338         private XmlTool() {
 339         }
 340 }