--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/misc/UCDecoder.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,233 @@
+/*
+ * Copyright 1995-2000 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package sun.misc;
+
+import java.io.OutputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.PushbackInputStream;
+import java.io.PrintStream;
+import java.io.IOException;
+
+/**
+ * This class implements a robust character decoder. The decoder will
+ * converted encoded text into binary data.
+ *
+ * The basic encoding unit is a 3 character atom. It encodes two bytes
+ * of data. Bytes are encoded into a 64 character set, the characters
+ * were chosen specifically because they appear in all codesets.
+ * We don't care what their numerical equivalent is because
+ * we use a character array to map them. This is like UUencoding
+ * with the dependency on ASCII removed.
+ *
+ * The three chars that make up an atom are encoded as follows:
+ * <pre>
+ * 00xxxyyy 00axxxxx 00byyyyy
+ * 00 = leading zeros, all values are 0 - 63
+ * xxxyyy - Top 3 bits of X, Top 3 bits of Y
+ * axxxxx - a = X parity bit, xxxxx lower 5 bits of X
+ * byyyyy - b = Y parity bit, yyyyy lower 5 bits of Y
+ * </pre>
+ *
+ * The atoms are arranged into lines suitable for inclusion into an
+ * email message or text file. The number of bytes that are encoded
+ * per line is 48 which keeps the total line length under 80 chars)
+ *
+ * Each line has the form(
+ * <pre>
+ * *(LLSS)(DDDD)(DDDD)(DDDD)...(CRC)
+ * Where each (xxx) represents a three character atom.
+ * (LLSS) - 8 bit length (high byte), and sequence number
+ * modulo 256;
+ * (DDDD) - Data byte atoms, if length is odd, last data
+ * atom has (DD00) (high byte data, low byte 0)
+ * (CRC) - 16 bit CRC for the line, includes length,
+ * sequence, and all data bytes. If there is a
+ * zero pad byte (odd length) it is _NOT_
+ * included in the CRC.
+ * </pre>
+ *
+ * If an error is encountered during decoding this class throws a
+ * CEFormatException. The specific detail messages are:
+ *
+ * <pre>
+ * "UCDecoder: High byte parity error."
+ * "UCDecoder: Low byte parity error."
+ * "UCDecoder: Out of sequence line."
+ * "UCDecoder: CRC check failed."
+ * </pre>
+ *
+ * @author Chuck McManis
+ * @see CharacterEncoder
+ * @see UCEncoder
+ */
+public class UCDecoder extends CharacterDecoder {
+
+ /** This class encodes two bytes per atom. */
+ protected int bytesPerAtom() {
+ return (2);
+ }
+
+ /** this class encodes 48 bytes per line */
+ protected int bytesPerLine() {
+ return (48);
+ }
+
+ /* this is the UCE mapping of 0-63 to characters .. */
+ private final static byte map_array[] = {
+ // 0 1 2 3 4 5 6 7
+ (byte)'0',(byte)'1',(byte)'2',(byte)'3',(byte)'4',(byte)'5',(byte)'6',(byte)'7', // 0
+ (byte)'8',(byte)'9',(byte)'A',(byte)'B',(byte)'C',(byte)'D',(byte)'E',(byte)'F', // 1
+ (byte)'G',(byte)'H',(byte)'I',(byte)'J',(byte)'K',(byte)'L',(byte)'M',(byte)'N', // 2
+ (byte)'O',(byte)'P',(byte)'Q',(byte)'R',(byte)'S',(byte)'T',(byte)'U',(byte)'V', // 3
+ (byte)'W',(byte)'X',(byte)'Y',(byte)'Z',(byte)'a',(byte)'b',(byte)'c',(byte)'d', // 4
+ (byte)'e',(byte)'f',(byte)'g',(byte)'h',(byte)'i',(byte)'j',(byte)'k',(byte)'l', // 5
+ (byte)'m',(byte)'n',(byte)'o',(byte)'p',(byte)'q',(byte)'r',(byte)'s',(byte)'t', // 6
+ (byte)'u',(byte)'v',(byte)'w',(byte)'x',(byte)'y',(byte)'z',(byte)'(',(byte)')' // 7
+ };
+
+ private int sequence;
+ private byte tmp[] = new byte[2];
+ private CRC16 crc = new CRC16();
+
+ /**
+ * Decode one atom - reads the characters from the input stream, decodes
+ * them, and checks for valid parity.
+ */
+ protected void decodeAtom(PushbackInputStream inStream, OutputStream outStream, int l) throws IOException {
+ int i, p1, p2, np1, np2;
+ byte a = -1, b = -1, c = -1;
+ byte high_byte, low_byte;
+ byte tmp[] = new byte[3];
+
+ i = inStream.read(tmp);
+ if (i != 3) {
+ throw new CEStreamExhausted();
+ }
+ for (i = 0; (i < 64) && ((a == -1) || (b == -1) || (c == -1)); i++) {
+ if (tmp[0] == map_array[i]) {
+ a = (byte) i;
+ }
+ if (tmp[1] == map_array[i]) {
+ b = (byte) i;
+ }
+ if (tmp[2] == map_array[i]) {
+ c = (byte) i;
+ }
+ }
+ high_byte = (byte) (((a & 0x38) << 2) + (b & 0x1f));
+ low_byte = (byte) (((a & 0x7) << 5) + (c & 0x1f));
+ p1 = 0;
+ p2 = 0;
+ for (i = 1; i < 256; i = i * 2) {
+ if ((high_byte & i) != 0)
+ p1++;
+ if ((low_byte & i) != 0)
+ p2++;
+ }
+ np1 = (b & 32) / 32;
+ np2 = (c & 32) / 32;
+ if ((p1 & 1) != np1) {
+ throw new CEFormatException("UCDecoder: High byte parity error.");
+ }
+ if ((p2 & 1) != np2) {
+ throw new CEFormatException("UCDecoder: Low byte parity error.");
+ }
+ outStream.write(high_byte);
+ crc.update(high_byte);
+ if (l == 2) {
+ outStream.write(low_byte);
+ crc.update(low_byte);
+ }
+ }
+
+ private ByteArrayOutputStream lineAndSeq = new ByteArrayOutputStream(2);
+
+ /**
+ * decodeBufferPrefix initializes the sequence number to zero.
+ */
+ protected void decodeBufferPrefix(PushbackInputStream inStream, OutputStream outStream) {
+ sequence = 0;
+ }
+
+ /**
+ * decodeLinePrefix reads the sequence number and the number of
+ * encoded bytes from the line. If the sequence number is not the
+ * previous sequence number + 1 then an exception is thrown.
+ * UCE lines are line terminator immune, they all start with *
+ * so the other thing this method does is scan for the next line
+ * by looking for the * character.
+ *
+ * @exception CEFormatException out of sequence lines detected.
+ */
+ protected int decodeLinePrefix(PushbackInputStream inStream, OutputStream outStream) throws IOException {
+ int i;
+ int nLen, nSeq;
+ byte xtmp[];
+ int c;
+
+ crc.value = 0;
+ while (true) {
+ c = inStream.read(tmp, 0, 1);
+ if (c == -1) {
+ throw new CEStreamExhausted();
+ }
+ if (tmp[0] == '*') {
+ break;
+ }
+ }
+ lineAndSeq.reset();
+ decodeAtom(inStream, lineAndSeq, 2);
+ xtmp = lineAndSeq.toByteArray();
+ nLen = xtmp[0] & 0xff;
+ nSeq = xtmp[1] & 0xff;
+ if (nSeq != sequence) {
+ throw new CEFormatException("UCDecoder: Out of sequence line.");
+ }
+ sequence = (sequence + 1) & 0xff;
+ return (nLen);
+ }
+
+
+ /**
+ * this method reads the CRC that is at the end of every line and
+ * verifies that it matches the computed CRC.
+ *
+ * @exception CEFormatException if CRC check fails.
+ */
+ protected void decodeLineSuffix(PushbackInputStream inStream, OutputStream outStream) throws IOException {
+ int i;
+ int lineCRC = crc.value;
+ int readCRC;
+ byte tmp[];
+
+ lineAndSeq.reset();
+ decodeAtom(inStream, lineAndSeq, 2);
+ tmp = lineAndSeq.toByteArray();
+ readCRC = ((tmp[0] << 8) & 0xFF00) + (tmp[1] & 0xff);
+ if (readCRC != lineCRC) {
+ throw new CEFormatException("UCDecoder: CRC check failed.");
+ }
+ }
+}