/*
* 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 com.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.lang.reflect.Method;
import java.net.URL;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.StringTokenizer;
import java.security.PrivilegedAction;
import java.security.AccessController;
/**
* 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: 1.3 $ $Date: 2005/09/28 13:49:04 $
* @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 = "com/sun/org/apache/xml/internal/serializer/Encodings.properties";
/**
* Standard filename for properties file with encodings data.
*/
private static final String ENCODINGS_PROP = "com.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
{
for (int i = 0; i < _encodings.length; ++i)
{
if (_encodings[i].name.equalsIgnoreCase(encoding))
{
try
{
return new OutputStreamWriter(
output,
_encodings[i].javaName);
}
catch (java.lang.IllegalArgumentException iae) // java 1.1.8
{
// keep trying
}
catch (UnsupportedEncodingException usee)
{
// keep trying
}
}
}
try
{
return new OutputStreamWriter(output, encoding);
}
catch (java.lang.IllegalArgumentException iae) // java 1.1.8
{
throw new UnsupportedEncodingException(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 = (EncodingInfo) _encodingTableKeyJava.get(normalizedEncoding);
if (ei == null)
ei = (EncodingInfo) _encodingTableKeyMime.get(normalizedEncoding);
if (ei == null) {
// We shouldn't have to do this, but just in case.
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 = System.getProperty("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)
{
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();
}
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