/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2000-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xerces" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, International
* Business Machines, Inc., http://www.apache.org. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package com.sun.org.apache.xml.internal.serialize;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import com.sun.org.apache.xerces.internal.util.EncodingMap;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.UnsupportedCharsetException;
import java.nio.charset.IllegalCharsetNameException;
/**
* This class represents an encoding.
*
* @version $Id: EncodingInfo.java,v 1.2 2003/12/05 10:08:55 vk112360 Exp $
*/
public class EncodingInfo {
// Method: sun.io.CharToByteConverter.getConverter(java.lang.String)
private static java.lang.reflect.Method fgGetConverterMethod = null;
// Method: sun.io.CharToByteConverter.canConvert(char)
private static java.lang.reflect.Method fgCanConvertMethod = null;
// Flag indicating whether or not sun.io.CharToByteConverter is available.
private static boolean fgConvertersAvailable = false;
// An array to hold the argument for a method of CharToByteConverter.
private Object [] fArgsForMethod = null;
// name of encoding as registered with IANA;
// preferably a MIME name, but aliases are fine too.
String ianaName;
String javaName;
int lastPrintable;
// The charToByteConverter with which we test unusual characters.
Object fCharToByteConverter = null;
// Is the converter null because it can't be instantiated
// for some reason (perhaps we're running with insufficient authority as
// an applet?
boolean fHaveTriedCToB = false;
Charset nioCharset = null;
CharsetEncoder nioCharEncoder = null;
/**
* Creates new <code>EncodingInfo</code> instance.
*/
public EncodingInfo(String ianaName, String javaName, int lastPrintable) {
this.ianaName = ianaName;
this.javaName = EncodingMap.getIANA2JavaMapping(ianaName);
this.lastPrintable = lastPrintable;
try{
nioCharset = Charset.forName(this.javaName);
if(nioCharset.canEncode())
nioCharEncoder = nioCharset.newEncoder();
}catch(IllegalCharsetNameException ie){
nioCharset = null;
nioCharEncoder = null;
}catch(UnsupportedCharsetException ue){
nioCharset = null;
nioCharEncoder = null;
}
}
/**
* Returns a MIME charset name of this encoding.
*/
public String getIANAName() {
return this.ianaName;
}
/**
* Returns a writer for this encoding based on
* an output stream.
*
* @return A suitable writer
* @exception UnsupportedEncodingException There is no convertor
* to support this encoding
*/
public Writer getWriter(OutputStream output)
throws UnsupportedEncodingException {
// this should always be true!
if (javaName != null)
return new OutputStreamWriter(output, javaName);
javaName = EncodingMap.getIANA2JavaMapping(ianaName);
if(javaName == null)
// use UTF-8 as preferred encoding
return new OutputStreamWriter(output, "UTF8");
return new OutputStreamWriter(output, javaName);
}
/**
* Checks whether the specified character is printable or not
* in this encoding.
*
* @param ch a code point (0-0x10ffff)
*/
public boolean isPrintable(char ch) {
if(ch <= this.lastPrintable)
return true;
if(nioCharEncoder != null)
return nioCharEncoder.canEncode(ch);
//We should not reach here , if we reach due to
//charset not supporting encoding then fgConvertersAvailable
//should take care of returning false.
if(fCharToByteConverter == null) {
if(fHaveTriedCToB || !fgConvertersAvailable) {
// forget it; nothing we can do...
return false;
}
if (fArgsForMethod == null) {
fArgsForMethod = new Object [1];
}
// try and create it:
try {
fArgsForMethod[0] = javaName;
fCharToByteConverter = fgGetConverterMethod.invoke(null, fArgsForMethod);
} catch(Exception e) {
// don't try it again...
fHaveTriedCToB = true;
return false;
}
}
try {
fArgsForMethod[0] = new Character(ch);
return ((Boolean) fgCanConvertMethod.invoke(fCharToByteConverter, fArgsForMethod)).booleanValue();
} catch (Exception e) {
// obviously can't use this converter; probably some kind of
// security restriction
fCharToByteConverter = null;
fHaveTriedCToB = false;
return false;
}
}
// is this an encoding name recognized by this JDK?
// if not, will throw UnsupportedEncodingException
public static void testJavaEncodingName(String name) throws UnsupportedEncodingException {
final byte [] bTest = {(byte)'v', (byte)'a', (byte)'l', (byte)'i', (byte)'d'};
String s = new String(bTest, name);
}
// Attempt to get methods for char to byte
// converter on class initialization.
static {
try {
Class clazz = Class.forName("sun.io.CharToByteConverter");
fgGetConverterMethod = clazz.getMethod("getConverter", new Class [] {String.class});
fgCanConvertMethod = clazz.getMethod("canConvert", new Class [] {Character.TYPE});
fgConvertersAvailable = true;
}
// ClassNotFoundException, NoSuchMethodException or SecurityException
// Whatever the case, we cannot use sun.io.CharToByteConverter.
catch (Exception exc) {
fgGetConverterMethod = null;
fgCanConvertMethod = null;
fgConvertersAvailable = false;
}
}
}
|
