/*
* 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.
*/
/*
* $Id: Encodings.java 471981 2006-11-07 04:28:00Z minchau $
*/
package org.apache.xml.serializer;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.List;
import java.util.Properties;
import java.util.StringTokenizer;
/**
* Provides information about encodings. Depends on the Java runtime
* to provides writers for the different encodings.
* <p>
* This class is not a public API. It is only public because it
* is used outside of this package.
*
* @xsl.usage internal
*/
public final class Encodings extends Object
{
/**
* Standard filename for properties file with encodings data.
*/
private static final String ENCODINGS_FILE = SerializerBase.PKG_PATH+"/Encodings.properties";
/**
* Returns a writer for the specified encoding based on
* an output stream.
* <p>
* This is not a public API.
* @param output The output stream
* @param encoding The encoding MIME name, not a Java name for the encoding.
* @return A suitable writer
* @throws UnsupportedEncodingException There is no convertor
* to support this encoding
* @xsl.usage internal
*/
static Writer getWriter(OutputStream output, String encoding)
throws UnsupportedEncodingException
{
for (int i = 0; i < _encodings.length; ++i)
{
if (_encodings[i].name.equalsIgnoreCase(encoding))
{
try
{
String javaName = _encodings[i].javaName;
OutputStreamWriter osw = new OutputStreamWriter(output,javaName);
return osw;
}
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 EncodingInfo object for the specified
* encoding, never null, although the encoding name
* inside the returned EncodingInfo object will be if
* we can't find a "real" EncodingInfo for the 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, '\u0000');
}
return ei;
}
/**
* Determines if the encoding specified was recognized by the
* serializer or not.
*
* @param encoding The encoding
* @return boolean - true if the encoding was recognized else false
*/
public static boolean isRecognizedEncoding(String encoding)
{
EncodingInfo ei;
String normalizedEncoding = encoding.toUpperCase();
ei = (EncodingInfo) _encodingTableKeyJava.get(normalizedEncoding);
if (ei == null)
ei = (EncodingInfo) _encodingTableKeyMime.get(normalizedEncoding);
if (ei != null)
return true;
return false;
}
/**
* 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."
* <p>
* This is not a public API.
*
* @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.
* @xsl.usage internal
*/
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.
* <p>
* This is not a public API.
* @param encoding non-null reference to encoding string, java style.
*
* @return ISO-style encoding string.
* @xsl.usage internal
*/
private static String convertJava2MimeEncoding(String encoding)
{
EncodingInfo enc =
(EncodingInfo) _encodingTableKeyJava.get(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.
* <p>
* This is not a public API.
*
* @param encoding non-null reference to encoding string, java style.
*
* @return ISO-style encoding string.
* <p>
* This method is not a public API.
* @xsl.usage internal
*/
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!
* @xsl.usage internal
*/
private static EncodingInfo[] loadEncodingInfo()
{
try
{
final InputStream is;
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();
List encodingInfo_list = new ArrayList();
Enumeration keys = props.keys();
for (int i = 0; i < totalEntries; ++i)
{
String javaName = (String) keys.nextElement();
String val = props.getProperty(javaName);
int len = lengthOfMimeNames(val);
String mimeName;
char highChar;
if (len == 0)
{
// There is no property value, only the javaName, so try and recover
mimeName = javaName;
highChar = '\u0000'; // don't know the high code point, will need to test every character
}
else
{
try {
// Get the substring after the Mime names
final String highVal = val.substring(len).trim();
highChar = (char) Integer.decode(highVal).intValue();
}
catch( NumberFormatException e) {
highChar = 0;
}
String mimeNames = val.substring(0, len);
StringTokenizer st =
new StringTokenizer(mimeNames, ",");
for (boolean first = true;
st.hasMoreTokens();
first = false)
{
mimeName = st.nextToken();
EncodingInfo ei = new EncodingInfo(mimeName, javaName, highChar);
encodingInfo_list.add(ei);
_encodingTableKeyMime.put(mimeName.toUpperCase(), ei);
if (first)
_encodingTableKeyJava.put(javaName.toUpperCase(), ei);
}
}
}
// Convert the Vector of EncodingInfo objects into an array of them,
// as that is the kind of thing this method returns.
EncodingInfo[] ret_ei = new EncodingInfo[encodingInfo_list.size()];
encodingInfo_list.toArray(ret_ei);
return ret_ei;
}
catch (java.net.MalformedURLException mue)
{
throw new org.apache.xml.serializer.utils.WrappedRuntimeException(mue);
}
catch (java.io.IOException ioe)
{
throw new org.apache.xml.serializer.utils.WrappedRuntimeException(ioe);
}
}
/**
* Get the length of the Mime names within the property value
* @param val The value of the property, which should contain a comma
* separated list of Mime names, followed optionally by a space and the
* high char value
* @return
*/
private static int lengthOfMimeNames(String val) {
// look for the space preceding the optional high char
int len = val.indexOf(' ');
// If len is zero it means the optional part is not there, so
// the value must be all Mime names, so set the length appropriately
if (len < 0)
len = val.length();
return len;
}
/**
* 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;
}
/**
* Characters with values at or below the high code point are
* in the encoding. Code point values above this one may or may
* not be in the encoding, but lower ones certainly are.
* <p>
* This is for performance.
*
* @param encoding The encoding
* @return The code point for which characters at or below this code point
* are in the encoding. Characters with higher code point may or may not be
* in the encoding. A value of zero is returned if the high code point is unknown.
* <p>
* This method is not a public API.
* @xsl.usage internal
*/
static public char getHighChar(String encoding)
{
final char highCodePoint;
EncodingInfo ei;
String normalizedEncoding = toUpperCaseFast(encoding);
ei = (EncodingInfo) _encodingTableKeyJava.get(normalizedEncoding);
if (ei == null)
ei = (EncodingInfo) _encodingTableKeyMime.get(normalizedEncoding);
if (ei != null)
highCodePoint = ei.getHighChar();
else
highCodePoint = 0;
return highCodePoint;
}
private static final Hashtable _encodingTableKeyJava = new Hashtable();
private static final Hashtable _encodingTableKeyMime = new Hashtable();
private static final EncodingInfo[] _encodings = loadEncodingInfo();
}