encodings.java

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                            || 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)
    {
        EncodingInfo enc =
            (EncodingInfo) _encodingTableKeyJava.get(encoding.toUpperCase());
        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)
    {

        for (int i = 0; i < _encodings.length; ++i)
        {
            if (_encodings[i].name.equalsIgnoreCase(encoding))
            {
                return _encodings[i].javaName;
            }
        }

        return encoding;
    }

    /**
     * Load 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 static EncodingInfo[] loadEncodingInfo()
    {
        URL url = null;
        try
        {
            String urlString = null;
            InputStream is = null;

            try
            {
                urlString = System.getProperty(ENCODINGS_PROP, "");
            }
            catch (SecurityException e)
            {
            }

            if (urlString != null && urlString.length() > 0) {
                url = new URL(urlString);
                is = url.openStream();
            }

            if (is == null) {
                SecuritySupport ss = SecuritySupport.getInstance();
                is = ss.getResourceAsStream(ObjectFactory.findClassLoader(),
                                            ENCODINGS_FILE);
            }

            Properties props = new Properties();
            if (is != null) {
                props.load(is);
                is.close();
            } 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)?
            }

            int totalEntries = props.size();
            int totalMimeNames = 0;
            Enumeration keys = props.keys();
            for (int i = 0; i < totalEntries; ++i)
            {
                String javaName = (String) keys.nextElement();
                String val = props.getProperty(javaName);
                totalMimeNames++;
                int pos = val.indexOf(' ');
                for (int j = 0; j < pos; ++j)
                    if (val.charAt(j) == ',')
                        totalMimeNames++;
            }
            EncodingInfo[] ret = new EncodingInfo[totalMimeNames];
            int j = 0;
            keys = props.keys();
            for (int i = 0; i < totalEntries; ++i)
            {
                String javaName = (String) keys.nextElement();
                String val = props.getProperty(javaName);
                int pos = val.indexOf(' ');
                String mimeName;
                //int lastPrintable;
                if (pos < 0)
                {
                    // Maybe report/log this problem?
                    //  "Last printable character not defined for encoding " +
                    //  mimeName + " (" + val + ")" ...
                    mimeName = val;
                    //lastPrintable = 0x00FF;
                }
                else
                {
                    //lastPrintable =
                    //    Integer.decode(val.substring(pos).trim()).intValue();
                    StringTokenizer st =
                        new StringTokenizer(val.substring(0, pos), ",");
                    for (boolean first = true;
                        st.hasMoreTokens();
                        first = false)
                    {
                        mimeName = st.nextToken();
                        ret[j] =
                            new EncodingInfo(mimeName, javaName);
                        _encodingTableKeyMime.put(
                            mimeName.toUpperCase(),
                            ret[j]);
                        if (first)
                            _encodingTableKeyJava.put(
                                javaName.toUpperCase(),
                                ret[j]);
                        j++;
                    }
                }
            }
            return ret;
        }
        catch (java.net.MalformedURLException mue)
        {
            throw new com.sun.org.apache.xml.internal.serializer.utils.WrappedRuntimeException(mue);
        }
        catch (java.io.IOException ioe)
        {
            throw new com.sun.org.apache.xml.internal.serializer.utils.WrappedRuntimeException(ioe);
        }
    }

    /**
     * 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 static final Hashtable _encodingTableKeyJava = new Hashtable();
    private static final Hashtable _encodingTableKeyMime = new Hashtable();
    private static final EncodingInfo[] _encodings = loadEncodingInfo();
}