/*
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* 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.io;
import java.io.*;
/**
* Convert byte arrays containing Unicode characters into arrays of actual
* Unicode characters. This class may be used directly, in which case it
* expects the input byte array to begin with a byte-order mark, or it may be
* subclassed in order to preset the byte order and mark behavior.
*
* <p> Whether or not a mark is expected, if a mark that does not match the
* established byte order is later discovered then a
* <tt>MalformedInputException</tt> will be thrown by the <tt>convert</tt>
* method. If a correct mark is seen later in the input stream, it is passed
* through as a character.
*
* @see ByteToCharUnicodeLittle
* @see ByteToCharUnicodeLittleUnmarked
* @see ByteToCharUnicodeBig
* @see ByteToCharUnicodeBigUnmarked
*
* @author Mark Reinhold
*/
public class ByteToCharUnicode extends ByteToCharConverter {
static final char BYTE_ORDER_MARK = (char) 0xfeff;
static final char REVERSED_MARK = (char) 0xfffe;
static final int AUTO = 0;
static final int BIG = 1;
static final int LITTLE = 2;
int originalByteOrder; /* Byte order specified at creation */
int byteOrder; /* Byte order in use */
boolean usesMark; /* Look for a mark and interpret it */
/**
* Creates a Unicode byte-to-char converter that expects the first pair of
* input bytes to be a byte-order mark, which will be interpreted and
* discarded. If the first pair of bytes is not such a mark then a
* <tt>MalformedInputException</tt> will be thrown by the convert method.
*/
public ByteToCharUnicode() {
originalByteOrder = byteOrder = AUTO;
usesMark = true;
}
/**
* Creates a Unicode byte-to-char converter that uses the given byte order
* and may or may not insist upon an initial byte-order mark.
*/
protected ByteToCharUnicode(int bo, boolean m) {
originalByteOrder = byteOrder = bo;
usesMark = m;
}
public String getCharacterEncoding() {
switch (originalByteOrder) {
case BIG:
return usesMark ? "UnicodeBig" : "UnicodeBigUnmarked";
case LITTLE:
return usesMark ? "UnicodeLittle" : "UnicodeLittleUnmarked";
default:
return "Unicode";
}
}
boolean started = false;
int leftOverByte;
boolean leftOver = false;
public int convert(byte[] in, int inOff, int inEnd,
char[] out, int outOff, int outEnd)
throws ConversionBufferFullException, MalformedInputException
{
byteOff = inOff;
charOff = outOff;
if (inOff >= inEnd)
return 0;
int b1, b2;
int bc = 0;
int inI = inOff, outI = outOff;
if (leftOver) {
b1 = leftOverByte & 0xff;
leftOver = false;
}
else {
b1 = in[inI++] & 0xff;
}
bc = 1;
if (usesMark && !started) { /* Read initial byte-order mark */
if (inI < inEnd) {
b2 = in[inI++] & 0xff;
bc = 2;
char c = (char) ((b1 << 8) | b2);
int bo = AUTO;
if (c == BYTE_ORDER_MARK)
bo = BIG;
else if (c == REVERSED_MARK)
bo = LITTLE;
if (byteOrder == AUTO) {
if (bo == AUTO) {
badInputLength = bc;
throw new
MalformedInputException("Missing byte-order mark");
}
byteOrder = bo;
if (inI < inEnd) {
b1 = in[inI++] & 0xff;
bc = 1;
}
}
else if (bo == AUTO) {
inI--;
bc = 1;
}
else if (byteOrder == bo) {
if (inI < inEnd) {
b1 = in[inI++] & 0xff;
bc = 1;
}
}
else {
badInputLength = bc;
throw new
MalformedInputException("Incorrect byte-order mark");
}
started = true;
}
}
/* Loop invariant: (b1 contains the next input byte) && (bc == 1) */
while (inI < inEnd) {
b2 = in[inI++] & 0xff;
bc = 2;
char c;
if (byteOrder == BIG)
c = (char) ((b1 << 8) | b2);
else
c = (char) ((b2 << 8) | b1);
if (c == REVERSED_MARK)
throw new
MalformedInputException("Reversed byte-order mark");
if (outI >= outEnd)
throw new ConversionBufferFullException();
out[outI++] = c;
byteOff = inI;
charOff = outI;
if (inI < inEnd) {
b1 = in[inI++] & 0xff;
bc = 1;
}
}
if (bc == 1) {
leftOverByte = b1;
byteOff = inI;
leftOver = true;
}
return outI - outOff;
}
public void reset() {
leftOver = false;
byteOff = charOff = 0;
started = false;
byteOrder = originalByteOrder;
}
public int flush(char buf[], int off, int len)
throws MalformedInputException
{
if (leftOver) {
reset();
throw new MalformedInputException();
}
byteOff = charOff = 0;
return 0;
}
}