1 /*

     2  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 /*

    27  */

    28 

    29 package sun.nio.cs.ext;

    30 

    31 import java.nio.ByteBuffer;

    32 import java.nio.CharBuffer;

    33 import java.nio.charset.Charset;

    34 import java.nio.charset.CharsetDecoder;

    35 import java.nio.charset.CharsetEncoder;

    36 import java.nio.charset.CoderResult;

    37 import sun.nio.cs.HistoricallyNamedCharset;

    38 

    39 public class SJIS

    40     extends Charset

    41     implements HistoricallyNamedCharset

    42 {

    43 

    44     public SJIS() {

    45         super("Shift_JIS", ExtendedCharsets.aliasesFor("Shift_JIS"));

    46     }

    47 

    48     public String historicalName() {

    49         return "SJIS";

    50     }

    51 

    52     public boolean contains(Charset cs) {

    53         return ((cs.name().equals("US-ASCII"))

    54                 || (cs instanceof JIS_X_0201)

    55                 || (cs instanceof SJIS)

    56                 || (cs instanceof JIS_X_0208));

    57     }

    58 

    59     public CharsetDecoder newDecoder() {

    60         return new Decoder(this);

    61     }

    62 

    63     public CharsetEncoder newEncoder() {

    64 

    65         // Need to force the replacement byte to 0x3f

    66         // because JIS_X_0208_Encoder defines its own

    67         // alternative 2 byte substitution to permit it

    68         // to exist as a self-standing Encoder

    69 

    70         byte[] replacementBytes = { (byte)0x3f };

    71         return new Encoder(this).replaceWith(replacementBytes);

    72     }

    73 

    74     static class Decoder extends JIS_X_0208_Decoder

    75         implements DelegatableDecoder {

    76 

    77         JIS_X_0201.Decoder jis0201;

    78 

    79         protected Decoder(Charset cs) {

    80             super(cs);

    81             jis0201 = new JIS_X_0201.Decoder(cs);

    82         }

    83 

    84         protected char decodeSingle(int b) {

    85             // If the high bits are all off, it's ASCII == Unicode

    86             if ((b & 0xFF80) == 0) {

    87                 return (char)b;

    88             }

    89             return jis0201.decode(b);

    90         }

    91 

    92         protected char decodeDouble(int c1, int c2) {

    93             int adjust = c2 < 0x9F ? 1 : 0;

    94             int rowOffset = c1 < 0xA0 ? 0x70 : 0xB0;

    95             int cellOffset = (adjust == 1) ? (c2 > 0x7F ? 0x20 : 0x1F) : 0x7E;

    96             int b1 = ((c1 - rowOffset) << 1) - adjust;

    97             int b2 = c2 - cellOffset;

    98             return super.decodeDouble(b1, b2);

    99         }

   100 

   101         // Make some protected methods public for use by JISAutoDetect

   102         public CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {

   103             return super.decodeLoop(src, dst);

   104         }

   105         public void implReset() {

   106             super.implReset();

   107         }

   108         public CoderResult implFlush(CharBuffer out) {

   109             return super.implFlush(out);

   110         }

   111     }

   112 

   113     static class Encoder extends JIS_X_0208_Encoder {

   114 

   115         private JIS_X_0201.Encoder jis0201;

   116 

   117         private static final short[] j0208Index1 =

   118             JIS_X_0208_Encoder.getIndex1();

   119         private static final String[] j0208Index2 =

   120             JIS_X_0208_Encoder.getIndex2();

   121 

   122         protected Encoder(Charset cs) {

   123             super(cs);

   124             jis0201 = new JIS_X_0201.Encoder(cs);

   125         }

   126 

   127         protected int encodeSingle(char inputChar) {

   128             byte b;

   129 

   130             // \u0000 - \u007F map straight through

   131             if ((inputChar & 0xFF80) == 0)

   132                 return (byte)inputChar;

   133 

   134             if ((b = jis0201.encode(inputChar)) == 0)

   135                 return -1;

   136             else

   137                 return b;

   138         }

   139 

   140         protected int encodeDouble(char ch) {

   141             int offset = j0208Index1[ch >> 8] << 8;

   142             int pos = j0208Index2[offset >> 12].charAt((offset & 0xfff) + (ch & 0xff));

   143             if (pos == 0) {

   144                 /* Zero value indicates this Unicode has no mapping to

   145                  * JIS0208.

   146                  * We bail here because the JIS -> SJIS algorithm produces

   147                  * bogus SJIS values for invalid JIS input.  Zero should be

   148                  * the only invalid JIS value in our table.

   149                  */

   150                 return 0;

   151             }

   152             /*

   153              * This algorithm for converting from JIS to SJIS comes from

   154              * Ken Lunde's "Understanding Japanese Information Processing",

   155              * pg 163.

   156              */

   157             int c1 = (pos >> 8) & 0xff;

   158             int c2 = pos & 0xff;

   159             int rowOffset = c1 < 0x5F ? 0x70 : 0xB0;

   160             int cellOffset = (c1 % 2 == 1) ? (c2 > 0x5F ? 0x20 : 0x1F) : 0x7E;

   161             return ((((c1 + 1 ) >> 1) + rowOffset) << 8) | (c2 + cellOffset);

   162         }

   163     }

   164 }