content: /*
   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * Licensed 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.
   */
  /*
   * $Id: Encodings.java,v 1.3 2005/09/28 13:49:04 pvedula Exp $
   */
  package jaxp.sun.org.apache.xml.internal.serializer;
  
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.io.UnsupportedEncodingException;
  import java.io.Writer;
  import java.io.BufferedWriter;
  import java.net.URL;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Properties;
  import java.util.StringTokenizer;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.nio.charset.Charset;
  import java.nio.charset.IllegalCharsetNameException;
  import java.nio.charset.UnsupportedCharsetException;
  import java.util.Collections;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import jaxp.sun.org.apache.xalan.internal.utils.SecuritySupport;
  
  import jaxp.sun.org.apache.xml.internal.serializer.utils.WrappedRuntimeException;
  
  /**
   * Provides information about encodings. Depends on the Java runtime
   * to provides writers for the different encodings, but can be used
   * to override encoding names and provide the last printable character
   * for each encoding.
   *
   * @version $Revision: 1.11 $ $Date: 2010-11-01 04:34:44 $
   * @author <a href="mailto:arkin@intalio.com">Assaf Arkin</a>
   */
  
  public final class Encodings extends Object
  {
  
      /**
       * The last printable character for unknown encodings.
       */
      private static final int m_defaultLastPrintable = 0x7F;
  
      /**
       * Standard filename for properties file with encodings data.
       */
      private static final String ENCODINGS_FILE = "jaxp.sun/org/apache/xml/internal/serializer/Encodings.properties";
  
      /**
       * Standard filename for properties file with encodings data.
       */
      private static final String ENCODINGS_PROP = "jaxp.sun.org.apache.xalan.internal.serialize.encodings";
  
  
      /**
       * Returns a writer for the specified encoding based on
       * an output stream.
       *
       * @param output The output stream
       * @param encoding The encoding
       * @return A suitable writer
       * @throws UnsupportedEncodingException There is no convertor
       *  to support this encoding
       */
      static Writer getWriter(OutputStream output, String encoding)
          throws UnsupportedEncodingException
      {
  
          final EncodingInfo ei = _encodingInfos.findEncoding(toUpperCaseFast(encoding));
          if (ei != null) {
              try {
                  return new BufferedWriter(new OutputStreamWriter(
                          output, ei.javaName));
              } catch (UnsupportedEncodingException usee) {
                  // keep trying
              }
          }
  
          return new BufferedWriter(new OutputStreamWriter(output, encoding));
      }
  
  
      /**
       * Returns the last printable character for an unspecified
       * encoding.
       *
       * @return the default size
       */
      public static int getLastPrintable()
      {
          return m_defaultLastPrintable;
      }
  
  
  
      /**
       * Returns the EncodingInfo object for the specified
       * encoding.
       * <p>
       * This is not a public API.
       *
       * @param encoding The encoding
       * @return The object that is used to determine if
       * characters are in the given encoding.
       * @xsl.usage internal
       */
      static EncodingInfo getEncodingInfo(String encoding)
      {
          EncodingInfo ei;
  
          String normalizedEncoding = toUpperCaseFast(encoding);
          ei = _encodingInfos.findEncoding(normalizedEncoding);
          if (ei == null) {
              // We shouldn't have to do this, but just in case.
              try {
                  // This may happen if the caller tries to use
                  // an encoding that wasn't registered in the
                  // (java name)->(preferred mime name) mapping file.
                  // In that case we attempt to load the charset for the
                  // given encoding, and if that succeeds - we create a new
                  // EncodingInfo instance - assuming the canonical name
                  // of the charset can be used as the mime name.
                  final Charset c = Charset.forName(encoding);
                  final String name = c.name();
                  ei = new EncodingInfo(name, name);
                  _encodingInfos.putEncoding(normalizedEncoding, ei);
              } catch (IllegalCharsetNameException | UnsupportedCharsetException x) {
                  ei = new EncodingInfo(null,null);
              }
          }
  
          return ei;
      }
  
      /**
       * A fast and cheap way to uppercase a String that is
       * only made of printable ASCII characters.
       * <p>
       * This is not a public API.
       * @param s a String of ASCII characters
       * @return an uppercased version of the input String,
       * possibly the same String.
       * @xsl.usage internal
       */
      static private String toUpperCaseFast(final String s) {
  
          boolean different = false;
          final int mx = s.length();
                  char[] chars = new char[mx];
          for (int i=0; i < mx; i++) {
                  char ch = s.charAt(i);
              // is the character a lower case ASCII one?
                  if ('a' <= ch && ch <= 'z') {
                  // a cheap and fast way to uppercase that is good enough
                          ch = (char) (ch + ('A' - 'a'));
                          different = true; // the uppercased String is different
                  }
                  chars[i] = ch;
          }
  
          // A little optimization, don't call String.valueOf() if
          // the uppercased string is the same as the input string.
          final String upper;
          if (different)
                  upper = String.valueOf(chars);
          else
                  upper = s;
  
          return upper;
      }
  
      /** The default encoding, ISO style, ISO style.   */
      static final String DEFAULT_MIME_ENCODING = "UTF-8";
  
      /**
       * Get the proper mime encoding.  From the XSLT recommendation: "The encoding
       * attribute specifies the preferred encoding to use for outputting the result
       * tree. XSLT processors are required to respect values of UTF-8 and UTF-16.
       * For other values, if the XSLT processor does not support the specified
       * encoding it may signal an error; if it does not signal an error it should
       * use UTF-8 or UTF-16 instead. The XSLT processor must not use an encoding
       * whose name does not match the EncName production of the XML Recommendation
       * [XML]. If no encoding attribute is specified, then the XSLT processor should
       * use either UTF-8 or UTF-16."
       *
       * @param encoding Reference to java-style encoding string, which may be null,
       * in which case a default will be found.
       *
       * @return The ISO-style encoding string, or null if failure.
       */
      static String getMimeEncoding(String encoding)
      {
  
          if (null == encoding)
          {
              try
              {
  
                  // Get the default system character encoding.  This may be
                  // incorrect if they passed in a writer, but right now there
                  // seems to be no way to get the encoding from a writer.
                  encoding = SecuritySupport.getSystemProperty("file.encoding", "UTF8");
  
                  if (null != encoding)
                  {
  
                      /*
                      * See if the mime type is equal to UTF8.  If you don't
                      * do that, then  convertJava2MimeEncoding will convert
                      * 8859_1 to "ISO-8859-1", which is not what we want,
                      * I think, and I don't think I want to alter the tables
                      * to convert everything to UTF-8.
                      */
                      String jencoding =
                          (encoding.equalsIgnoreCase("Cp1252")
                              || encoding.equalsIgnoreCase("ISO8859_1")
                              || encoding.equalsIgnoreCase("8859_1")
                              || encoding.equalsIgnoreCase("UTF8"))
                              ? DEFAULT_MIME_ENCODING
                              : convertJava2MimeEncoding(encoding);
  
                      encoding =
                          (null != jencoding) ? jencoding : DEFAULT_MIME_ENCODING;
                  }
                  else
                  {
                      encoding = DEFAULT_MIME_ENCODING;
                  }
              }
              catch (SecurityException se)
              {
                  encoding = DEFAULT_MIME_ENCODING;
              }
          }
          else
          {
              encoding = convertJava2MimeEncoding(encoding);
          }
  
          return encoding;
      }
  
      /**
       * Try the best we can to convert a Java encoding to a XML-style encoding.
       *
       * @param encoding non-null reference to encoding string, java style.
       *
       * @return ISO-style encoding string.
       */
      private static String convertJava2MimeEncoding(String encoding)
      {
          final EncodingInfo enc =
               _encodingInfos.getEncodingFromJavaKey(toUpperCaseFast(encoding));
          if (null != enc)
              return enc.name;
          return encoding;
      }
  
      /**
       * Try the best we can to convert a Java encoding to a XML-style encoding.
       *
       * @param encoding non-null reference to encoding string, java style.
       *
       * @return ISO-style encoding string.
       */
      public static String convertMime2JavaEncoding(String encoding)
      {
          final EncodingInfo info = _encodingInfos.findEncoding(toUpperCaseFast(encoding));
          return info != null ? info.javaName : encoding;
      }
  
      // Using an inner static class here prevent initialization races
      // where the hash maps could be used before they were populated.
      //
      private final static class EncodingInfos {
          // These maps are final and not modified after initialization.
          private final Map<String, EncodingInfo> _encodingTableKeyJava = new HashMap<>();
          private final Map<String, EncodingInfo> _encodingTableKeyMime = new HashMap<>();
          // This map will be added to after initialization: make sure it's
          // thread-safe. This map should not be used frequently - only in cases
          // where the mapping requested was not declared in the Encodings.properties
          // file.
          private final Map<String, EncodingInfo> _encodingDynamicTable =
                  Collections.synchronizedMap(new HashMap<String, EncodingInfo>());
  
          private EncodingInfos() {
              loadEncodingInfo();
          }
  
          // Opens the file/resource containing java charset name -> preferred mime
          // name mapping and returns it as an InputStream.
          private InputStream openEncodingsFileStream() throws MalformedURLException, IOException {
              String urlString = null;
              InputStream is = null;
  
              try {
                  urlString = SecuritySupport.getSystemProperty(ENCODINGS_PROP, "");
              } catch (SecurityException e) {
              }
  
              if (urlString != null && urlString.length() > 0) {
                  URL url = new URL(urlString);
                  is = url.openStream();
              }
  
              if (is == null) {
                  is = SecuritySupport.getResourceAsStream(ENCODINGS_FILE);
              }
              return is;
          }
  
          // Loads the Properties resource containing the mapping:
          //    java charset name -> preferred mime name
          // and returns it.
          private Properties loadProperties() throws MalformedURLException, IOException {
              Properties props = new Properties();
              try (InputStream is = openEncodingsFileStream()) {
                  if (is != null) {
                      props.load(is);
                  } else {
                      // Seems to be no real need to force failure here, let the
                      // system do its best... The issue is not really very critical,
                      // and the output will be in any case _correct_ though maybe not
                      // always human-friendly... :)
                      // But maybe report/log the resource problem?
                      // Any standard ways to report/log errors (in static context)?
                  }
              }
              return props;
          }
  
          // Parses the mime list associated to a java charset name.
          // The first mime name in the list is supposed to be the preferred
          // mime name.
          private String[] parseMimeTypes(String val) {
              int pos = val.indexOf(' ');
              //int lastPrintable;
              if (pos < 0) {
                  // Maybe report/log this problem?
                  //  "Last printable character not defined for encoding " +
                  //  mimeName + " (" + val + ")" ...
                  return new String[] { val };
                  //lastPrintable = 0x00FF;
              }
              //lastPrintable =
              //    Integer.decode(val.substring(pos).trim()).intValue();
              StringTokenizer st =
                      new StringTokenizer(val.substring(0, pos), ",");
              String[] values = new String[st.countTokens()];
              for (int i=0; st.hasMoreTokens(); i++) {
                  values[i] = st.nextToken();
              }
              return values;
          }
  
          // This method here attempts to find the canonical charset name for the
          // the given name - which is supposed to be either a java name or a mime
          // name.
          // For that, it attempts to load the charset using the given name, and
          // then returns the charset's canonical name.
          // If the charset could not be loaded from the given name,
          // the method returns null.
          private String findCharsetNameFor(String name) {
              try {
                  return Charset.forName(name).name();
              } catch (Exception x) {
                  return null;
              }
          }
  
          // This method here attempts to find the canonical charset name for the
          // the set javaName+mimeNames - which are supposed to all refer to the
          // same charset.
          // For that it attempts to load the charset using the javaName, and if
          // not found, attempts again using each of the mime names in turn.
          // If the charset could be loaded from the javaName, then the javaName
          // itself is returned as charset name. Otherwise, each of the mime names
          // is tried in turn, until a charset can be loaded from one of the names,
          // and the loaded charset's canonical name is returned.
          // If no charset can be loaded from either the javaName or one of the
          // mime names, then null is returned.
          //
          // Note that the returned name is the 'java' name that will be used in
          // instances of EncodingInfo.
          // This is important because EncodingInfo uses that 'java name' later on
          // in calls to String.getBytes(javaName).
          // As it happens, sometimes only one element of the set mime names/javaName
          // is known by Charset: sometimes only one of the mime names is known,
          // sometime only the javaName is known, sometimes all are known.
          //
          // By using this method here, we fix the problem where one of the mime
          // names is known but the javaName is unknown, by associating the charset
          // loaded from one of the mime names with the unrecognized javaName.
          //
          // When none of the mime names or javaName are known - there's not much we can
          // do... It can mean that this encoding is not supported for this
          // OS. If such a charset is ever use it will result in having all characters
          // escaped.
          //
          private String findCharsetNameFor(String javaName, String[] mimes) {
              String cs = findCharsetNameFor(javaName);
              if (cs != null) return javaName;
              for (String m : mimes) {
                  cs = findCharsetNameFor(m);
                  if (cs != null) break;
              }
              return cs;
          }
  
          /**
           * Loads a list of all the supported encodings.
           *
           * System property "encodings" formatted using URL syntax may define an
           * external encodings list. Thanks to Sergey Ushakov for the code
           * contribution!
           */
          private void loadEncodingInfo() {
              try {
                  // load (java name)->(preferred mime name) mapping.
                  final Properties props = loadProperties();
  
                  // create instances of EncodingInfo from the loaded mapping
                  Enumeration keys = props.keys();
                  Map<String, EncodingInfo> canonicals = new HashMap<>();
                  while (keys.hasMoreElements()) {
                      final String javaName = (String) keys.nextElement();
                      final String[] mimes = parseMimeTypes(props.getProperty(javaName));
  
                      final String charsetName = findCharsetNameFor(javaName, mimes);
                      if (charsetName != null) {
                          final String kj = toUpperCaseFast(javaName);
                          final String kc = toUpperCaseFast(charsetName);
                          for (int i = 0; i < mimes.length; ++i) {
                              final String mimeName = mimes[i];
                              final String km = toUpperCaseFast(mimeName);
                              EncodingInfo info = new EncodingInfo(mimeName, charsetName);
                              _encodingTableKeyMime.put(km, info);
                              if (!canonicals.containsKey(kc)) {
                                  // canonicals will map the charset name to
                                  //   the info containing the prefered mime name
                                  //   (the preferred mime name is the first mime
                                  //   name in the list).
                                  canonicals.put(kc, info);
                                  _encodingTableKeyJava.put(kc, info);
                              }
                              _encodingTableKeyJava.put(kj, info);
                          }
                      } else {
                          // None of the java or mime names on the line were
                          // recognized => this charset is not supported?
                      }
                  }
  
                  // Fix up the _encodingTableKeyJava so that the info mapped to
                  // the java name contains the preferred mime name.
                  // (a given java name can correspond to several mime name,
                  //  but we want the _encodingTableKeyJava to point to the
                  //  preferred mime name).
                  for (Entry<String, EncodingInfo> e : _encodingTableKeyJava.entrySet()) {
                      e.setValue(canonicals.get(toUpperCaseFast(e.getValue().javaName)));
                  }
  
              } catch (java.net.MalformedURLException mue) {
                  throw new WrappedRuntimeException(mue);
              } catch (java.io.IOException ioe) {
                  throw new WrappedRuntimeException(ioe);
              }
          }
  
          EncodingInfo findEncoding(String normalizedEncoding) {
              EncodingInfo info = _encodingTableKeyJava.get(normalizedEncoding);
              if (info == null) {
                  info = _encodingTableKeyMime.get(normalizedEncoding);
              }
              if (info == null) {
                  info = _encodingDynamicTable.get(normalizedEncoding);
              }
              return info;
          }
  
          EncodingInfo getEncodingFromMimeKey(String normalizedMimeName) {
              return _encodingTableKeyMime.get(normalizedMimeName);
          }
  
          EncodingInfo getEncodingFromJavaKey(String normalizedJavaName) {
              return _encodingTableKeyJava.get(normalizedJavaName);
          }
  
          void putEncoding(String key, EncodingInfo info) {
              _encodingDynamicTable.put(key, info);
          }
      }
  
      /**
       * Return true if the character is the high member of a surrogate pair.
       * <p>
       * This is not a public API.
       * @param ch the character to test
       * @xsl.usage internal
       */
      static boolean isHighUTF16Surrogate(char ch) {
          return ('\uD800' <= ch && ch <= '\uDBFF');
      }
      /**
       * Return true if the character is the low member of a surrogate pair.
       * <p>
       * This is not a public API.
       * @param ch the character to test
       * @xsl.usage internal
       */
      static boolean isLowUTF16Surrogate(char ch) {
          return ('\uDC00' <= ch && ch <= '\uDFFF');
      }
      /**
       * Return the unicode code point represented by the high/low surrogate pair.
       * <p>
       * This is not a public API.
       * @param highSurrogate the high char of the high/low pair
       * @param lowSurrogate the low char of the high/low pair
       * @xsl.usage internal
       */
      static int toCodePoint(char highSurrogate, char lowSurrogate) {
          int codePoint =
              ((highSurrogate - 0xd800) << 10)
                  + (lowSurrogate - 0xdc00)
                  + 0x10000;
          return codePoint;
      }
      /**
       * Return the unicode code point represented by the char.
       * A bit of a dummy method, since all it does is return the char,
       * but as an int value.
       * <p>
       * This is not a public API.
       * @param ch the char.
       * @xsl.usage internal
       */
      static int toCodePoint(char ch) {
          int codePoint = ch;
          return codePoint;
      }
  
      private final static EncodingInfos _encodingInfos = new EncodingInfos();
  
  }
  