/*
* @(#)ByteToCharDoubleByte.java 1.12 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package sun.io;
/**
* @author Limin Shi
* Sean Jiang
*/
public abstract class ByteToCharDoubleByte extends ByteToCharConverter {
protected byte savedByte;
/*
* 1st level index, provided by subclass
*/
protected short index1[];
/*
* 2nd level index, provided by subclass
* every string has 0x10*(end-start+1) characters.
*/
protected String index2[];
protected int start;
protected int end;
/*
* Size of bad input that caused conversion to stop
*/
protected int badInputLength;
public ByteToCharDoubleByte() {
super();
savedByte = 0;
}
public int flush(char[] output, int outStart, int outEnd)
throws MalformedInputException {
if (savedByte != 0) {
reset();
badInputLength = 0;
throw new MalformedInputException();
}
reset();
return 0;
}
/**
* Converts sequences of bytes to characters.
* Conversions that result in Exceptions can be restarted by calling
* convert again, with appropriately modified parameters.
* @return the characters written to output.
* @param input byte array containing text in Double/single Byte
* @param inStart offset in input array
* @param inEnd offset of last byte to be converted
* @param output character array to receive conversion result
* @param outStart starting offset
* @param outEnd offset of last byte to be written to
* @throw UnsupportedCharacterException for any bytes
* that cannot be converted to the external character set.
*/
public int convert(byte[] input, int inOff, int inEnd,
char[] output, int outOff, int outEnd)
throws UnknownCharacterException, MalformedInputException,
ConversionBufferFullException {
char outputChar = REPLACE_CHAR;
int inputSize = 0; // Size of input
// Record beginning offsets
charOff = outOff;
byteOff = inOff;
// Loop until we hit the end of the input
while (byteOff < inEnd) {
int byte1, byte2;
if (savedByte == 0) {
byte1 = input[byteOff];
inputSize = 1;
} else {
byte1 = savedByte;
savedByte = 0;
inputSize = 0;
}
outputChar = convSingleByte(byte1);
if (outputChar == REPLACE_CHAR) { // DoubleByte char
if (byteOff + inputSize >= inEnd) {
// split in the middle of a character
// save the first byte for next time around
savedByte = (byte) byte1;
byteOff += inputSize;
break;
}
byte1 &= 0xff;
byte2 = input[byteOff + inputSize] & 0xff;
inputSize++;
outputChar = getUnicode(byte1, byte2);
}
if (outputChar == REPLACE_CHAR) {
if (subMode)
outputChar = subChars[0];
else {
badInputLength = inputSize;
throw new UnknownCharacterException();
}
}
if (charOff >= outEnd)
throw new ConversionBufferFullException();
output[charOff++] = outputChar;
byteOff += inputSize;
}
return charOff - outOff;
}
/**
* Resets the converter.
* Call this method to reset the converter to its initial state
*/
public void reset() {
byteOff = charOff = 0;
savedByte = 0;
}
/*
* Can be changed by subclass
*/
protected char convSingleByte(int b) {
if (b >= 0)
return (char) b;
return REPLACE_CHAR;
}
/*
* Can be changed by subclass
*/
protected char getUnicode(int byte1, int byte2) {
if ((byte2 < start) || (byte2 > end))
return REPLACE_CHAR;
int n = (index1[byte1] & 0xf) * (end - start + 1) + (byte2 - start);
return index2[index1[byte1] >> 4].charAt(n);
}
protected final static char REPLACE_CHAR = '\uFFFD';
}