1 /*
2 * Copyright 2003-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 /*
27 */
28
29 /**
30 * Simple EUC-like decoder used by IBM01383 and IBM970
31 * supports G1 - no support for G2 or G3
32 */
33
34
35 import java.nio.ByteBuffer;
36 import java.nio.CharBuffer;
37 import java.nio.charset.Charset;
38 import java.nio.charset.CharsetDecoder;
39 import java.nio.charset.CoderResult;
40
41 abstract class SimpleEUCDecoder
42 extends CharsetDecoder
43 {
44 private final int SS2 = 0x8E;
45 private final int SS3 = 0x8F;
46
47 protected static String mappingTableG1;
48 protected static String byteToCharTable;
49
50 protected SimpleEUCDecoder(Charset cs) {
51 super(cs, 0.5f, 1.0f);
52 }
53
54 private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {
55 byte[] sa = src.array();
56 int sp = src.arrayOffset() + src.position();
57 int sl = src.arrayOffset() + src.limit();
58 assert (sp <= sl);
59 sp = (sp <= sl ? sp : sl);
60 char[] da = dst.array();
61 int dp = dst.arrayOffset() + dst.position();
62 int dl = dst.arrayOffset() + dst.limit();
63 assert (dp <= dl);
64 dp = (dp <= dl ? dp : dl);
65
66 try {
67 while (sp < sl) {
68 int byte1, byte2;
69 int inputSize = 1;
70 char outputChar = '\uFFFD';
71
72 byte1 = sa[sp] & 0xff;
73
74 if ( byte1 <= 0x9f ) { // < 0x9f has its own table (G0)
75 if (byte1 == SS2 || byte1 == SS3 ) {
76 // No support provided for G2/G3 at this time.
77 return CoderResult.malformedForLength(1);
78 }
79 outputChar = byteToCharTable.charAt(byte1);
80 } else if (byte1 < 0xa1 || byte1 > 0xfe) { // invalid range?
81 return CoderResult.malformedForLength(1);
82 } else { // (G1)
83 if (sl - sp < 2) {
84 return CoderResult.UNDERFLOW;
85 }
86 byte2 = sa[sp + 1] & 0xff;
87 inputSize++;
88 if ( byte2 < 0xa1 || byte2 > 0xfe) {
89 return CoderResult.malformedForLength(2);
90 }
91 outputChar = mappingTableG1.charAt(((byte1 - 0xa1) * 94) + byte2 - 0xa1);
92 }
93 if (outputChar == '\uFFFD') {
94 return CoderResult.unmappableForLength(inputSize);
95 }
96 if (dl - dp < 1)
97 return CoderResult.OVERFLOW;
98 da[dp++] = outputChar;
99 sp += inputSize;
100 }
101 return CoderResult.UNDERFLOW;
102 } finally {
103 src.position(sp - src.arrayOffset());
104 dst.position(dp - dst.arrayOffset());
105 }
106 }
107
108 private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {
109 int mark = src.position();
110
111 try {
112 while (src.hasRemaining()) {
113 char outputChar = '\uFFFD';
114 int inputSize = 1;
115 int byte1, byte2;
116
117 byte1 = src.get() & 0xff;
118 if ( byte1 <= 0x9f ) {
119 if (byte1 == SS2 || byte1 == SS3 ) {
120 return CoderResult.malformedForLength(1);
121 }
122 outputChar = byteToCharTable.charAt(byte1);
123 } else if (byte1 < 0xa1 || byte1 > 0xfe) {
124 return CoderResult.malformedForLength(1);
125 } else {
126 if (!src.hasRemaining()) {
127 return CoderResult.UNDERFLOW;
128 }
129 byte2 = src.get() & 0xff;
130 inputSize++;
131 if ( byte2 < 0xa1 || byte2 > 0xfe) {
132 return CoderResult.malformedForLength(2);
133 }
134 outputChar = mappingTableG1.charAt(((byte1 - 0xa1) * 94) + byte2 - 0xa1);
135 }
136 if (outputChar == '\uFFFD') {
137 return CoderResult.unmappableForLength(inputSize);
138 }
139 if (!dst.hasRemaining())
140 return CoderResult.OVERFLOW;
141 dst.put(outputChar);
142 mark += inputSize;
143 }
144 return CoderResult.UNDERFLOW;
145 } finally {
146 src.position(mark);
147 }
148 }
149
150 protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
151 if (src.hasArray() && dst.hasArray())
152 return decodeArrayLoop(src, dst);
153 else
154 return decodeBufferLoop(src, dst);
155 }
156 }