Coverage Report

Coverage Report - org.apache.commons.io.input.XmlStreamReader

Classes in this File
Line Coverage
Branch Coverage
Complexity
XmlStreamReader
88%
170/193
92%
148/160
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.commons.io.input;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.io.StringReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.net.URLConnection;
 import java.text.MessageFormat;
 import java.util.Locale;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.apache.commons.io.ByteOrderMark;
 
 /**
  * Character stream that handles all the necessary Voodo to figure out the
  * charset encoding of the XML document within the stream.
  * <p>
  * IMPORTANT: This class is not related in any way to the org.xml.sax.XMLReader.
  * This one IS a character stream.
  * <p>
  * All this has to be done without consuming characters from the stream, if not
  * the XML parser will not recognized the document as a valid XML. This is not
  * 100% true, but it's close enough (UTF-8 BOM is not handled by all parsers
  * right now, XmlStreamReader handles it and things work in all parsers).
  * <p>
  * The XmlStreamReader class handles the charset encoding of XML documents in
  * Files, raw streams and HTTP streams by offering a wide set of constructors.
  * <p>
  * By default the charset encoding detection is lenient, the constructor with
  * the lenient flag can be used for an script (following HTTP MIME and XML
  * specifications). All this is nicely explained by Mark Pilgrim in his blog, <a
  * href="http://diveintomark.org/archives/2004/02/13/xml-media-types">
  * Determining the character encoding of a feed</a>.
  * <p>
  * Originally developed for <a href="http://rome.dev.java.net">ROME</a> under
  * Apache License 2.0.
  *
  * @version $Id: XmlStreamReader.java 1471788 2013-04-24 23:58:56Z sebb $
  * @see org.apache.commons.io.output.XmlStreamWriter
  * @since 2.0
  */
 public class XmlStreamReader extends Reader {
     private static final int BUFFER_SIZE = 4096;
 
     private static final String UTF_8 = "UTF-8";
 
     private static final String US_ASCII = "US-ASCII";
 
     private static final String UTF_16BE = "UTF-16BE";
 
     private static final String UTF_16LE = "UTF-16LE";
 
     private static final String UTF_32BE = "UTF-32BE";
 
     private static final String UTF_32LE = "UTF-32LE";
 
     private static final String UTF_16 = "UTF-16";
 
     private static final String UTF_32 = "UTF-32";
 
     private static final String EBCDIC = "CP1047";
 
     private static final ByteOrderMark[] BOMS = new ByteOrderMark[] {
         ByteOrderMark.UTF_8,
         ByteOrderMark.UTF_16BE,
         ByteOrderMark.UTF_16LE,
         ByteOrderMark.UTF_32BE,
         ByteOrderMark.UTF_32LE
     };
 
     // UTF_16LE and UTF_32LE have the same two starting BOM bytes.
     private static final ByteOrderMark[] XML_GUESS_BYTES = new ByteOrderMark[] {
         new ByteOrderMark(UTF_8,    0x3C, 0x3F, 0x78, 0x6D),
         new ByteOrderMark(UTF_16BE, 0x00, 0x3C, 0x00, 0x3F),
         new ByteOrderMark(UTF_16LE, 0x3C, 0x00, 0x3F, 0x00),
         new ByteOrderMark(UTF_32BE, 0x00, 0x00, 0x00, 0x3C,
                 0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x78, 0x00, 0x00, 0x00, 0x6D),
         new ByteOrderMark(UTF_32LE, 0x3C, 0x00, 0x00, 0x00,
                 0x3F, 0x00, 0x00, 0x00, 0x78, 0x00, 0x00, 0x00, 0x6D, 0x00, 0x00, 0x00),
         new ByteOrderMark(EBCDIC,   0x4C, 0x6F, 0xA7, 0x94)
     };
 
     private final Reader reader;
 
     private final String encoding;
 
     private final String defaultEncoding;
 
     /**
      * Returns the default encoding to use if none is set in HTTP content-type,
      * XML prolog and the rules based on content-type are not adequate.
      * <p>
      * If it is NULL the content-type based rules are used.
      *
      * @return the default encoding to use.
      */
     public String getDefaultEncoding() {
         return defaultEncoding;
     }
 
     /**
      * Creates a Reader for a File.
      * <p>
      * It looks for the UTF-8 BOM first, if none sniffs the XML prolog charset,
      * if this is also missing defaults to UTF-8.
      * <p>
      * It does a lenient charset encoding detection, check the constructor with
      * the lenient parameter for details.
      *
      * @param file File to create a Reader from.
      * @throws IOException thrown if there is a problem reading the file.
      */
     public XmlStreamReader(final File file) throws IOException {
         this(new FileInputStream(file));
     }
 
     /**
      * Creates a Reader for a raw InputStream.
      * <p>
      * It follows the same logic used for files.
      * <p>
      * It does a lenient charset encoding detection, check the constructor with
      * the lenient parameter for details.
      *
      * @param is InputStream to create a Reader from.
      * @throws IOException thrown if there is a problem reading the stream.
      */
     public XmlStreamReader(final InputStream is) throws IOException {
         this(is, true);
     }
 
     /**
      * Creates a Reader for a raw InputStream.
      * <p>
      * It follows the same logic used for files.
      * <p>
      * If lenient detection is indicated and the detection above fails as per
      * specifications it then attempts the following:
      * <p>
      * If the content type was 'text/html' it replaces it with 'text/xml' and
      * tries the detection again.
      * <p>
      * Else if the XML prolog had a charset encoding that encoding is used.
      * <p>
      * Else if the content type had a charset encoding that encoding is used.
      * <p>
      * Else 'UTF-8' is used.
      * <p>
      * If lenient detection is indicated an XmlStreamReaderException is never
      * thrown.
      *
      * @param is InputStream to create a Reader from.
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @throws IOException thrown if there is a problem reading the stream.
      * @throws XmlStreamReaderException thrown if the charset encoding could not
      *         be determined according to the specs.
      */
     public XmlStreamReader(final InputStream is, final boolean lenient) throws IOException {
         this(is, lenient, null);
     }
 
     /**
      * Creates a Reader for a raw InputStream.
      * <p>
      * It follows the same logic used for files.
      * <p>
      * If lenient detection is indicated and the detection above fails as per
      * specifications it then attempts the following:
      * <p>
      * If the content type was 'text/html' it replaces it with 'text/xml' and
      * tries the detection again.
      * <p>
      * Else if the XML prolog had a charset encoding that encoding is used.
      * <p>
      * Else if the content type had a charset encoding that encoding is used.
      * <p>
      * Else 'UTF-8' is used.
      * <p>
      * If lenient detection is indicated an XmlStreamReaderException is never
      * thrown.
      *
      * @param is InputStream to create a Reader from.
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @param defaultEncoding The default encoding
      * @throws IOException thrown if there is a problem reading the stream.
      * @throws XmlStreamReaderException thrown if the charset encoding could not
      *         be determined according to the specs.
      */
     public XmlStreamReader(final InputStream is, final boolean lenient, final String defaultEncoding) throws IOException {
         this.defaultEncoding = defaultEncoding;
         final BOMInputStream bom = new BOMInputStream(new BufferedInputStream(is, BUFFER_SIZE), false, BOMS);
         final BOMInputStream pis = new BOMInputStream(bom, true, XML_GUESS_BYTES);
         this.encoding = doRawStream(bom, pis, lenient);
         this.reader = new InputStreamReader(pis, encoding);
     }
 
     /**
      * Creates a Reader using the InputStream of a URL.
      * <p>
      * If the URL is not of type HTTP and there is not 'content-type' header in
      * the fetched data it uses the same logic used for Files.
      * <p>
      * If the URL is a HTTP Url or there is a 'content-type' header in the
      * fetched data it uses the same logic used for an InputStream with
      * content-type.
      * <p>
      * It does a lenient charset encoding detection, check the constructor with
      * the lenient parameter for details.
      *
      * @param url URL to create a Reader from.
      * @throws IOException thrown if there is a problem reading the stream of
      *         the URL.
      */
     public XmlStreamReader(final URL url) throws IOException {
         this(url.openConnection(), null);
     }
 
     /**
      * Creates a Reader using the InputStream of a URLConnection.
      * <p>
      * If the URLConnection is not of type HttpURLConnection and there is not
      * 'content-type' header in the fetched data it uses the same logic used for
      * files.
      * <p>
      * If the URLConnection is a HTTP Url or there is a 'content-type' header in
      * the fetched data it uses the same logic used for an InputStream with
      * content-type.
      * <p>
      * It does a lenient charset encoding detection, check the constructor with
      * the lenient parameter for details.
      *
      * @param conn URLConnection to create a Reader from.
      * @param defaultEncoding The default encoding
      * @throws IOException thrown if there is a problem reading the stream of
      *         the URLConnection.
      */
     public XmlStreamReader(final URLConnection conn, final String defaultEncoding) throws IOException {
         this.defaultEncoding = defaultEncoding;
         final boolean lenient = true;
         final String contentType = conn.getContentType();
         final InputStream is = conn.getInputStream();
         final BOMInputStream bom = new BOMInputStream(new BufferedInputStream(is, BUFFER_SIZE), false, BOMS);
         final BOMInputStream pis = new BOMInputStream(bom, true, XML_GUESS_BYTES);
         if (conn instanceof HttpURLConnection || contentType != null) {
             this.encoding = doHttpStream(bom, pis, contentType, lenient);
         } else {
             this.encoding = doRawStream(bom, pis, lenient);
         }
         this.reader = new InputStreamReader(pis, encoding);
     }
 
     /**
      * Creates a Reader using an InputStream an the associated content-type
      * header.
      * <p>
      * First it checks if the stream has BOM. If there is not BOM checks the
      * content-type encoding. If there is not content-type encoding checks the
      * XML prolog encoding. If there is not XML prolog encoding uses the default
      * encoding mandated by the content-type MIME type.
      * <p>
      * It does a lenient charset encoding detection, check the constructor with
      * the lenient parameter for details.
      *
      * @param is InputStream to create the reader from.
      * @param httpContentType content-type header to use for the resolution of
      *        the charset encoding.
      * @throws IOException thrown if there is a problem reading the file.
      */
     public XmlStreamReader(final InputStream is, final String httpContentType)
             throws IOException {
         this(is, httpContentType, true);
     }
 
     /**
      * Creates a Reader using an InputStream an the associated content-type
      * header. This constructor is lenient regarding the encoding detection.
      * <p>
      * First it checks if the stream has BOM. If there is not BOM checks the
      * content-type encoding. If there is not content-type encoding checks the
      * XML prolog encoding. If there is not XML prolog encoding uses the default
      * encoding mandated by the content-type MIME type.
      * <p>
      * If lenient detection is indicated and the detection above fails as per
      * specifications it then attempts the following:
      * <p>
      * If the content type was 'text/html' it replaces it with 'text/xml' and
      * tries the detection again.
      * <p>
      * Else if the XML prolog had a charset encoding that encoding is used.
      * <p>
      * Else if the content type had a charset encoding that encoding is used.
      * <p>
      * Else 'UTF-8' is used.
      * <p>
      * If lenient detection is indicated an XmlStreamReaderException is never
      * thrown.
      *
      * @param is InputStream to create the reader from.
      * @param httpContentType content-type header to use for the resolution of
      *        the charset encoding.
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @param defaultEncoding The default encoding
      * @throws IOException thrown if there is a problem reading the file.
      * @throws XmlStreamReaderException thrown if the charset encoding could not
      *         be determined according to the specs.
      */
     public XmlStreamReader(final InputStream is, final String httpContentType,
             final boolean lenient, final String defaultEncoding) throws IOException {
         this.defaultEncoding = defaultEncoding;
         final BOMInputStream bom = new BOMInputStream(new BufferedInputStream(is, BUFFER_SIZE), false, BOMS);
         final BOMInputStream pis = new BOMInputStream(bom, true, XML_GUESS_BYTES);
         this.encoding = doHttpStream(bom, pis, httpContentType, lenient);
         this.reader = new InputStreamReader(pis, encoding);
     }
 
     /**
      * Creates a Reader using an InputStream an the associated content-type
      * header. This constructor is lenient regarding the encoding detection.
      * <p>
      * First it checks if the stream has BOM. If there is not BOM checks the
      * content-type encoding. If there is not content-type encoding checks the
      * XML prolog encoding. If there is not XML prolog encoding uses the default
      * encoding mandated by the content-type MIME type.
      * <p>
      * If lenient detection is indicated and the detection above fails as per
      * specifications it then attempts the following:
      * <p>
      * If the content type was 'text/html' it replaces it with 'text/xml' and
      * tries the detection again.
      * <p>
      * Else if the XML prolog had a charset encoding that encoding is used.
      * <p>
      * Else if the content type had a charset encoding that encoding is used.
      * <p>
      * Else 'UTF-8' is used.
      * <p>
      * If lenient detection is indicated an XmlStreamReaderException is never
      * thrown.
      *
      * @param is InputStream to create the reader from.
      * @param httpContentType content-type header to use for the resolution of
      *        the charset encoding.
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @throws IOException thrown if there is a problem reading the file.
      * @throws XmlStreamReaderException thrown if the charset encoding could not
      *         be determined according to the specs.
      */
     public XmlStreamReader(final InputStream is, final String httpContentType,
             final boolean lenient) throws IOException {
         this(is, httpContentType, lenient, null);
     }
 
     /**
      * Returns the charset encoding of the XmlStreamReader.
      *
      * @return charset encoding.
      */
     public String getEncoding() {
         return encoding;
     }
 
     /**
      * Invokes the underlying reader's <code>read(char[], int, int)</code> method.
      * @param buf the buffer to read the characters into
      * @param offset The start offset
      * @param len The number of bytes to read
      * @return the number of characters read or -1 if the end of stream
      * @throws IOException if an I/O error occurs
      */
     @Override
     public int read(final char[] buf, final int offset, final int len) throws IOException {
         return reader.read(buf, offset, len);
     }
 
     /**
      * Closes the XmlStreamReader stream.
      *
      * @throws IOException thrown if there was a problem closing the stream.
      */
     @Override
     public void close() throws IOException {
         reader.close();
     }
 
     /**
      * Process the raw stream.
      *
      * @param bom BOMInputStream to detect byte order marks
      * @param pis BOMInputStream to guess XML encoding
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @return the encoding to be used
      * @throws IOException thrown if there is a problem reading the stream.
      */
     private String doRawStream(final BOMInputStream bom, final BOMInputStream pis, final boolean lenient)
             throws IOException {
         final String bomEnc      = bom.getBOMCharsetName();
         final String xmlGuessEnc = pis.getBOMCharsetName();
         final String xmlEnc = getXmlProlog(pis, xmlGuessEnc);
         try {
             return calculateRawEncoding(bomEnc, xmlGuessEnc, xmlEnc);
         } catch (final XmlStreamReaderException ex) {
             if (lenient) {
                 return doLenientDetection(null, ex);
             } else {
                 throw ex;
             }
         }
     }
 
     /**
      * Process a HTTP stream.
      *
      * @param bom BOMInputStream to detect byte order marks
      * @param pis BOMInputStream to guess XML encoding
      * @param httpContentType The HTTP content type
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @return the encoding to be used
      * @throws IOException thrown if there is a problem reading the stream.
      */
     private String doHttpStream(final BOMInputStream bom, final BOMInputStream pis, final String httpContentType,
             final boolean lenient) throws IOException {
         final String bomEnc      = bom.getBOMCharsetName();
         final String xmlGuessEnc = pis.getBOMCharsetName();
         final String xmlEnc = getXmlProlog(pis, xmlGuessEnc);
         try {
             return calculateHttpEncoding(httpContentType, bomEnc,
                     xmlGuessEnc, xmlEnc, lenient);
         } catch (final XmlStreamReaderException ex) {
             if (lenient) {
                 return doLenientDetection(httpContentType, ex);
             } else {
                 throw ex;
             }
         }
     }
 
     /**
      * Do lenient detection.
      *
      * @param httpContentType content-type header to use for the resolution of
      *        the charset encoding.
      * @param ex The thrown exception
      * @return the encoding
      * @throws IOException thrown if there is a problem reading the stream.
      */
     private String doLenientDetection(String httpContentType,
             XmlStreamReaderException ex) throws IOException {
         if (httpContentType != null && httpContentType.startsWith("text/html")) {
             httpContentType = httpContentType.substring("text/html".length());
             httpContentType = "text/xml" + httpContentType;
             try {
                 return calculateHttpEncoding(httpContentType, ex.getBomEncoding(),
                         ex.getXmlGuessEncoding(), ex.getXmlEncoding(), true);
             } catch (final XmlStreamReaderException ex2) {
                 ex = ex2;
             }
         }
         String encoding = ex.getXmlEncoding();
         if (encoding == null) {
             encoding = ex.getContentTypeEncoding();
         }
         if (encoding == null) {
             encoding = defaultEncoding == null ? UTF_8 : defaultEncoding;
         }
         return encoding;
     }
 
     /**
      * Calculate the raw encoding.
      *
      * @param bomEnc BOM encoding
      * @param xmlGuessEnc XML Guess encoding
      * @param xmlEnc XML encoding
      * @return the raw encoding
      * @throws IOException thrown if there is a problem reading the stream.
      */
     String calculateRawEncoding(final String bomEnc, final String xmlGuessEnc,
             final String xmlEnc) throws IOException {
 
         // BOM is Null
         if (bomEnc == null) {
             if (xmlGuessEnc == null || xmlEnc == null) {
                 return defaultEncoding == null ? UTF_8 : defaultEncoding;
             }
             if (xmlEnc.equals(UTF_16) &&
                (xmlGuessEnc.equals(UTF_16BE) || xmlGuessEnc.equals(UTF_16LE))) {
                 return xmlGuessEnc;
             }
             return xmlEnc;
         }
 
         // BOM is UTF-8
         if (bomEnc.equals(UTF_8)) {
             if (xmlGuessEnc != null && !xmlGuessEnc.equals(UTF_8)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             if (xmlEnc != null && !xmlEnc.equals(UTF_8)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             return bomEnc;
         }
 
         // BOM is UTF-16BE or UTF-16LE
         if (bomEnc.equals(UTF_16BE) || bomEnc.equals(UTF_16LE)) {
             if (xmlGuessEnc != null && !xmlGuessEnc.equals(bomEnc)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             if (xmlEnc != null && !xmlEnc.equals(UTF_16) && !xmlEnc.equals(bomEnc)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             return bomEnc;
         }
 
         // BOM is UTF-32BE or UTF-32LE
         if (bomEnc.equals(UTF_32BE) || bomEnc.equals(UTF_32LE)) {
             if (xmlGuessEnc != null && !xmlGuessEnc.equals(bomEnc)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             if (xmlEnc != null && !xmlEnc.equals(UTF_32) && !xmlEnc.equals(bomEnc)) {
                 final String msg = MessageFormat.format(RAW_EX_1, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
                 throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
             }
             return bomEnc;
         }
 
         // BOM is something else
         final String msg = MessageFormat.format(RAW_EX_2, new Object[] { bomEnc, xmlGuessEnc, xmlEnc });
         throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
     }
 
 
     /**
      * Calculate the HTTP encoding.
      *
      * @param httpContentType The HTTP content type
      * @param bomEnc BOM encoding
      * @param xmlGuessEnc XML Guess encoding
      * @param xmlEnc XML encoding
      * @param lenient indicates if the charset encoding detection should be
      *        relaxed.
      * @return the HTTP encoding
      * @throws IOException thrown if there is a problem reading the stream.
      */
     String calculateHttpEncoding(final String httpContentType,
             final String bomEnc, final String xmlGuessEnc, final String xmlEnc,
             final boolean lenient) throws IOException {
 
         // Lenient and has XML encoding
         if (lenient && xmlEnc != null) {
             return xmlEnc;
         }
 
         // Determine mime/encoding content types from HTTP Content Type
         final String cTMime = getContentTypeMime(httpContentType);
         final String cTEnc  = getContentTypeEncoding(httpContentType);
         final boolean appXml  = isAppXml(cTMime);
         final boolean textXml = isTextXml(cTMime);
 
         // Mime type NOT "application/xml" or "text/xml"
         if (!appXml && !textXml) {
             final String msg = MessageFormat.format(HTTP_EX_3, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
             throw new XmlStreamReaderException(msg, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
         }
 
         // No content type encoding
         if (cTEnc == null) {
             if (appXml) {
                 return calculateRawEncoding(bomEnc, xmlGuessEnc, xmlEnc);
             } else {
                 return defaultEncoding == null ? US_ASCII : defaultEncoding;
             }
         }
 
         // UTF-16BE or UTF-16LE content type encoding
         if (cTEnc.equals(UTF_16BE) || cTEnc.equals(UTF_16LE)) {
             if (bomEnc != null) {
                 final String msg = MessageFormat.format(HTTP_EX_1, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
                 throw new XmlStreamReaderException(msg, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
             }
             return cTEnc;
         }
 
         // UTF-16 content type encoding
         if (cTEnc.equals(UTF_16)) {
             if (bomEnc != null && bomEnc.startsWith(UTF_16)) {
                 return bomEnc;
             }
             final String msg = MessageFormat.format(HTTP_EX_2, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
             throw new XmlStreamReaderException(msg, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
         }
 
         // UTF-32BE or UTF-132E content type encoding
         if (cTEnc.equals(UTF_32BE) || cTEnc.equals(UTF_32LE)) {
             if (bomEnc != null) {
                 final String msg = MessageFormat.format(HTTP_EX_1, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
                 throw new XmlStreamReaderException(msg, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
             }
             return cTEnc;
         }
 
         // UTF-32 content type encoding
         if (cTEnc.equals(UTF_32)) {
             if (bomEnc != null && bomEnc.startsWith(UTF_32)) {
                 return bomEnc;
             }
             final String msg = MessageFormat.format(HTTP_EX_2, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
             throw new XmlStreamReaderException(msg, cTMime, cTEnc, bomEnc, xmlGuessEnc, xmlEnc);
         }
 
         return cTEnc;
     }
 
     /**
      * Returns MIME type or NULL if httpContentType is NULL.
      *
      * @param httpContentType the HTTP content type
      * @return The mime content type
      */
     static String getContentTypeMime(final String httpContentType) {
         String mime = null;
         if (httpContentType != null) {
             final int i = httpContentType.indexOf(";");
             if (i >= 0) {
                 mime = httpContentType.substring(0, i);
             } else {
                 mime = httpContentType;
             }
             mime = mime.trim();
         }
         return mime;
     }
 
     private static final Pattern CHARSET_PATTERN = Pattern
             .compile("charset=[\"']?([.[^; \"']]*)[\"']?");
 
     /**
      * Returns charset parameter value, NULL if not present, NULL if
      * httpContentType is NULL.
      *
      * @param httpContentType the HTTP content type
      * @return The content type encoding (upcased)
      */
     static String getContentTypeEncoding(final String httpContentType) {
         String encoding = null;
         if (httpContentType != null) {
             final int i = httpContentType.indexOf(";");
             if (i > -1) {
                 final String postMime = httpContentType.substring(i + 1);
                 final Matcher m = CHARSET_PATTERN.matcher(postMime);
                 encoding = m.find() ? m.group(1) : null;
                 encoding = encoding != null ? encoding.toUpperCase(Locale.US) : null;
             }
         }
         return encoding;
     }
 
     public static final Pattern ENCODING_PATTERN = Pattern.compile(
             "<\\?xml.*encoding[\\s]*=[\\s]*((?:\".[^\"]*\")|(?:'.[^']*'))",
             Pattern.MULTILINE);
 
     /**
      * Returns the encoding declared in the <?xml encoding=...?>, NULL if none.
      *
      * @param is InputStream to create the reader from.
      * @param guessedEnc guessed encoding
      * @return the encoding declared in the <?xml encoding=...?>
      * @throws IOException thrown if there is a problem reading the stream.
      */
     private static String getXmlProlog(final InputStream is, final String guessedEnc)
             throws IOException {
         String encoding = null;
         if (guessedEnc != null) {
             final byte[] bytes = new byte[BUFFER_SIZE];
             is.mark(BUFFER_SIZE);
             int offset = 0;
             int max = BUFFER_SIZE;
             int c = is.read(bytes, offset, max);
             int firstGT = -1;
             String xmlProlog = ""; // avoid possible NPE warning (cannot happen; this just silences the warning)
             while (c != -1 && firstGT == -1 && offset < BUFFER_SIZE) {
                 offset += c;
                 max -= c;
                 c = is.read(bytes, offset, max);
                 xmlProlog = new String(bytes, 0, offset, guessedEnc);
                 firstGT = xmlProlog.indexOf('>');
             }
             if (firstGT == -1) {
                 if (c == -1) {
                     throw new IOException("Unexpected end of XML stream");
                 } else {
                     throw new IOException(
                             "XML prolog or ROOT element not found on first "
                                     + offset + " bytes");
                 }
             }
             final int bytesRead = offset;
             if (bytesRead > 0) {
                 is.reset();
                 final BufferedReader bReader = new BufferedReader(new StringReader(
                         xmlProlog.substring(0, firstGT + 1)));
                 final StringBuffer prolog = new StringBuffer();
                 String line = bReader.readLine();
                 while (line != null) {
                     prolog.append(line);
                     line = bReader.readLine();
                 }
                 final Matcher m = ENCODING_PATTERN.matcher(prolog);
                 if (m.find()) {
                     encoding = m.group(1).toUpperCase();
                     encoding = encoding.substring(1, encoding.length() - 1);
                 }
             }
         }
         return encoding;
     }
 
     /**
      * Indicates if the MIME type belongs to the APPLICATION XML family.
      *
      * @param mime The mime type
      * @return true if the mime type belongs to the APPLICATION XML family,
      * otherwise false
      */
     static boolean isAppXml(final String mime) {
         return mime != null &&
                (mime.equals("application/xml") ||
                 mime.equals("application/xml-dtd") ||
                 mime.equals("application/xml-external-parsed-entity") ||
                mime.startsWith("application/") && mime.endsWith("+xml"));
     }
 
     /**
      * Indicates if the MIME type belongs to the TEXT XML family.
      *
      * @param mime The mime type
      * @return true if the mime type belongs to the TEXT XML family,
      * otherwise false
      */
     static boolean isTextXml(final String mime) {
         return mime != null &&
               (mime.equals("text/xml") ||
                mime.equals("text/xml-external-parsed-entity") ||
               mime.startsWith("text/") && mime.endsWith("+xml"));
     }
 
     private static final String RAW_EX_1 =
         "Invalid encoding, BOM [{0}] XML guess [{1}] XML prolog [{2}] encoding mismatch";
 
     private static final String RAW_EX_2 =
         "Invalid encoding, BOM [{0}] XML guess [{1}] XML prolog [{2}] unknown BOM";
 
     private static final String HTTP_EX_1 =
         "Invalid encoding, CT-MIME [{0}] CT-Enc [{1}] BOM [{2}] XML guess [{3}] XML prolog [{4}], BOM must be NULL";
 
     private static final String HTTP_EX_2 =
         "Invalid encoding, CT-MIME [{0}] CT-Enc [{1}] BOM [{2}] XML guess [{3}] XML prolog [{4}], encoding mismatch";
 
     private static final String HTTP_EX_3 =
         "Invalid encoding, CT-MIME [{0}] CT-Enc [{1}] BOM [{2}] XML guess [{3}] XML prolog [{4}], Invalid MIME";
 
 }