ISO2022_CN_CNS.java

/*
 * Copyright (c) 2002, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.nio.cs.ext;

import java.nio.charset.Charset;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import sun.nio.cs.HistoricallyNamedCharset;

public class ISO2022_CN_CNS extends ISO2022 implements HistoricallyNamedCharset
{
    public ISO2022_CN_CNS() {
	super("x-ISO-2022-CN-CNS", ExtendedCharsets.aliasesFor("x-ISO-2022-CN-CNS"));
    }

    public boolean contains(Charset cs) {
	// overlapping repertoire of EUC_TW, CNS11643
	return ((cs instanceof EUC_TW) ||
		(cs.name().equals("US-ASCII")) ||
		(cs instanceof ISO2022_CN_CNS));
    }

    public String historicalName() {
	return "ISO2022CN_CNS";
    }

    public CharsetDecoder newDecoder() {
	return new ISO2022_CN.Decoder(this);
    }

    public CharsetEncoder newEncoder() {
	return new Encoder(this);
    }

    private static class Encoder extends ISO2022.Encoder {

	public Encoder(Charset cs)
	{
	    super(cs);
	    SODesig = "$)G";
	    SS2Desig = "$*H";
	    SS3Desig = "$+I";

	    try {
		Charset cset = Charset.forName("EUC_TW"); // CNS11643
		ISOEncoder = cset.newEncoder();
	    } catch (Exception e) { }
	}

	/*
	 * Since ISO2022-CN-CNS possesses a CharsetEncoder
	 * without the corresponding CharsetDecoder half the
	 * default replacement check needs to be overridden
	 * since the parent class version attempts to
	 * decode 0x3f (?).  
	 */

	public boolean isLegalReplacement(byte[] repl) {
	    // 0x3f is OK as the replacement byte
	    return (repl.length == 1 && repl[0] == (byte) 0x3f);
	}
    }
}