/* Provider.java --
Copyright (C) 2002, 2005, 2006 Free Software Foundation, Inc.
This file is part of GNU Classpath.
GNU Classpath 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 2, or (at your option)
any later version.
GNU Classpath is distributed in the hope that it will be useful, but
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
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along with GNU Classpath; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package gnu.java.nio.charset;
import java.nio.charset.Charset;
import java.nio.charset.spi.CharsetProvider;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
/**
* Charset provider for the required charsets. Used by
* {@link Charset#charsetForName} and * {@link Charset#availableCharsets}.
*
* Note: This class is a privileged class, because it can be instantiated without
* requiring the RuntimePermission("charsetProvider"). There is a check in
* java.nio.charset.spi.CharsetProvider to skip the security check if the provider
* is an instance of this class.
*
* @author Jesse Rosenstock
* @author Robert Schuster (thebohemian@gmx.net)
* @see Charset
*/
public final class Provider extends CharsetProvider
{
private static Provider singleton;
/**
* Map from charset name to charset canonical name. The strings
* are all lower-case to allow case-insensitive retrieval of
* Charset instances.
*/
private final HashMap canonicalNames;
/**
* Map from lower-case canonical name to Charset.
* TODO: We may want to use soft references. We would then need to keep
* track of the class name to regenerate the object.
*/
private final HashMap charsets;
/**
* We don't load all available charsets at the start
*/
private boolean extendedLoaded;
// Package private to avoid an accessor method in PrivilegedAction below.
Provider ()
{
extendedLoaded = false;
canonicalNames = new HashMap ();
charsets = new HashMap ();
// US-ASCII aka ISO646-US
addCharset (new US_ASCII ());
// ISO-8859-1 aka ISO-LATIN-1
addCharset (new ISO_8859_1 ());
// UTF-8
addCharset (new UTF_8 ());
// UTF-16BE
addCharset (new UTF_16BE ());
// UTF-16LE
addCharset (new UTF_16LE ());
// UTF-16
addCharset (new UTF_16 ());
// UTF-16LE (marked)
addCharset (new UnicodeLittle ());
// Windows-1250 aka cp-1250 (East European)
addCharset (new Windows1250 ());
// Windows-1251 (Cyrillic)
addCharset (new Windows1251 ());
// Windows-1252 aka cp-1252 (Latin-1)
addCharset (new Windows1252 ());
// Windows-1253 (Greek)
addCharset (new Windows1253 ());
// Windows-1254 (Turkish)
addCharset (new Windows1254 ());
// Windows-1257 (Baltic)
addCharset (new Windows1257 ());
// ISO-8859-2 aka ISO-LATIN-2
addCharset (new ISO_8859_2 ());
// ISO-8859-4 aka ISO-LATIN-4
addCharset (new ISO_8859_4 ());
// ISO-8859-5 (Cyrillic)
addCharset (new ISO_8859_5 ());
// ISO-8859-7 (Greek)
addCharset (new ISO_8859_7 ());
// ISO-8859-9 aka ISO-LATIN-5
addCharset (new ISO_8859_9 ());
// ISO-8859-13 aka ISO-LATIN-7
addCharset (new ISO_8859_13 ());
// ISO-8859-15 aka ISO-LATIN-9
addCharset (new ISO_8859_15 ());
// KOI8 (Cyrillic)
addCharset (new KOI_8 ());
}
/**
* Load non-mandatory charsets.
*/
private synchronized void loadExtended ()
{
if (extendedLoaded)
return;
addCharset (new ISO_8859_3 ()); // ISO-8859-3 aka ISO-LATIN-3
addCharset (new ISO_8859_6 ()); // ISO-8859-6 (Arabic)
addCharset (new ISO_8859_8 ()); // ISO-8859-8 (Hebrew)
// Some more codepages
addCharset (new Cp424());
addCharset (new Cp437());
addCharset (new Cp737());
addCharset (new Cp775());
addCharset (new Cp850());
addCharset (new Cp852());
addCharset (new Cp855()); // IBM Cyrillic
addCharset (new Cp857()); // IBM Turkish
addCharset (new Cp860()); // MSDOS Portugese
addCharset (new Cp861()); // MSDOS Icelandic
addCharset (new Cp862()); // PC Hebrew
addCharset (new Cp863()); // MSDOS Can. French
addCharset (new Cp864()); // PC Arabic
addCharset (new Cp865()); // MSDOS Nordic
addCharset (new Cp866()); // MSDOS Russian
addCharset (new Cp869()); // IBM modern Greek
addCharset (new Cp874()); // IBM Thai
addCharset (new MacCentralEurope());
addCharset (new MacCroatian());
addCharset (new MacCyrillic());
addCharset (new MacDingbat());
addCharset (new MacGreek());
addCharset (new MacIceland());
addCharset (new MacRoman());
addCharset (new MacRomania());
addCharset (new MacSymbol());
addCharset (new MacThai());
addCharset (new MacTurkish());
addCharset (new MS874());
addCharset (new Windows1255());
addCharset (new Windows1256());
addCharset (new Windows1258());
extendedLoaded = true;
}
public Iterator charsets ()
{
loadExtended();
return Collections.unmodifiableCollection (charsets.values ())
.iterator ();
}
/**
* Returns a Charset instance by converting the given
* name to lower-case, looking up the canonical charset
* name and finally looking up the Charset with that name.
*
* <p>The lookup is therefore case-insensitive.</p>
*
* @returns The Charset having <code>charsetName</code>
* as its alias or null if no such Charset exist.
*/
public Charset charsetForName (String charsetName)
{
Charset cs = (Charset) charsets.get(canonicalNames.get(charsetName.toLowerCase()));
if (cs == null)
{
loadExtended();
cs = (Charset) charsets.get(canonicalNames.get(charsetName.toLowerCase()));
}
return cs;
}
/**
* Puts a Charset under its canonical name into the 'charsets' map.
* Then puts a mapping from all its alias names to the canonical name.
*
* <p>All names are converted to lower-case</p>.
*
* @param cs
*/
private void addCharset (Charset cs)
{
String canonicalName = cs.name().toLowerCase();
charsets.put (canonicalName, cs);
/* Adds a mapping between the canonical name
* itself making a lookup using that name
* no special case.
*/
canonicalNames.put(canonicalName, canonicalName);
for (Iterator i = cs.aliases ().iterator (); i.hasNext (); )
canonicalNames.put (((String) i.next()).toLowerCase(), canonicalName);
}
public static synchronized Provider provider ()
{
// The default provider is safe to instantiate.
if (singleton == null)
singleton = (Provider) AccessController.doPrivileged
(new PrivilegedAction()
{
public Object run()
{
return new Provider();
}
});
return singleton;
}
}