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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;
Author: Limin Shi
/**
* @author Limin Shi
*/
public abstract class CharToByteDoubleByte extends CharToByteConverter {
/*
* 1st level index, provided by subclass
*/
protected short index1[];
/*
* 2nd level index, provided by subclass
*/
protected String index2[];
protected char highHalfZoneCode;
public short[] getIndex1() {
return index1;
}
public String[] getIndex2() {
return index2;
}
public int flush(byte[] output, int outStart, int outEnd)
throws MalformedInputException, ConversionBufferFullException
{
if (highHalfZoneCode != 0) {
highHalfZoneCode = 0;
badInputLength = 0;
throw new MalformedInputException();
}
byteOff = charOff = 0;
return 0;
}
Converts characters to sequences of bytes.
Conversions that result in Exceptions can be restarted by calling
convert again, with appropriately modified parameters.
Params: - input – char array containing text in Unicode
- inStart – offset in input array
- inEnd – offset of last byte to be converted
- output – byte array to receive conversion result
- outStart – starting offset
- outEnd – offset of last byte to be written to
Returns: the characters written to output. @throw UnsupportedCharacterException for any character
that cannot be converted to the external character set.
/**
* Converts characters to sequences of bytes.
* Conversions that result in Exceptions can be restarted by calling
* convert again, with appropriately modified parameters.
* @return the characters written to output.
* @param input char array containing text in Unicode
* @param inStart offset in input array
* @param inEnd offset of last byte to be converted
* @param output byte array to receive conversion result
* @param outStart starting offset
* @param outEnd offset of last byte to be written to
* @throw UnsupportedCharacterException for any character
* that cannot be converted to the external character set.
*/
public int convert(char[] input, int inOff, int inEnd,
byte[] output, int outOff, int outEnd)
throws MalformedInputException, UnknownCharacterException,
ConversionBufferFullException
{
char inputChar; // Input character to be converted
byte[] outputByte; // Output byte written to output
int inputSize = 0; // Size of input
int outputSize = 0; // Size of output
byte[] tmpbuf = new byte[2];
// Record beginning offsets
charOff = inOff;
byteOff = outOff;
if (highHalfZoneCode != 0) {
inputChar = highHalfZoneCode;
highHalfZoneCode = 0;
if (input[inOff] >= 0xdc00 && input[inOff] <= 0xdfff) {
// This is legal UTF16 sequence.
badInputLength = 1;
throw new UnknownCharacterException();
} else {
// This is illegal UTF16 sequence.
badInputLength = 0;
throw new MalformedInputException();
}
}
// Loop until we hit the end of the input
while(charOff < inEnd) {
inputSize = 1;
outputByte = tmpbuf;
inputChar = input[charOff]; // Get the input character
// Is this a high surrogate?
if(inputChar >= '\uD800' && inputChar <= '\uDBFF') {
// Is this the last character of the input?
if (charOff + 1 >= inEnd) {
highHalfZoneCode = inputChar;
break;
}
// Is there a low surrogate following?
inputChar = input[charOff + 1];
if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {
// We have a valid surrogate pair. Too bad we don't do
// surrogates. Is substitution enabled?
if (subMode) {
outputByte = subBytes;
outputSize = subBytes.length;
inputSize = 2;
} else {
badInputLength = 2;
throw new UnknownCharacterException();
}
} else {
// We have a malformed surrogate pair
badInputLength = 1;
throw new MalformedInputException();
}
}
// Is this an unaccompanied low surrogate?
else if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {
badInputLength = 1;
throw new MalformedInputException();
} else {
outputSize = convSingleByte(inputChar, outputByte);
if (outputSize == 0) { // DoubleByte
int ncode = getNative(inputChar);
if (ncode != 0 ) {
outputByte[0] = (byte) ((ncode & 0xff00) >> 8);
outputByte[1] = (byte) (ncode & 0xff);
outputSize = 2;
} else {
if (subMode) {
outputByte = subBytes;
outputSize = subBytes.length;
} else {
badInputLength = 1;
throw new UnknownCharacterException();
}
}
}
}
// If we don't have room for the output, throw an exception
if (byteOff + outputSize > outEnd)
throw new ConversionBufferFullException();
// Put the byte in the output buffer
for (int i = 0; i < outputSize; i++) {
output[byteOff++] = outputByte[i];
}
charOff += inputSize;
}
// Return the length written to the output buffer
return byteOff - outOff;
}
the maximum number of bytes needed to hold a converted char
@returns the maximum number of bytes needed for a converted char
/**
* the maximum number of bytes needed to hold a converted char
* @returns the maximum number of bytes needed for a converted char
*/
public int getMaxBytesPerChar() {
return 2;
}
Resets the converter.
Call this method to reset the converter to its initial state
/**
* Resets the converter.
* Call this method to reset the converter to its initial state
*/
public void reset() {
byteOff = charOff = 0;
highHalfZoneCode = 0;
}
Return whether a character is mappable or not
Returns: true if a character is mappable
/**
* Return whether a character is mappable or not
* @return true if a character is mappable
*/
public boolean canConvert(char ch) {
byte[] outByte = new byte[2];
if ((ch == (char) 0) || (convSingleByte(ch, outByte) != 0))
return true;
if (this.getNative(ch) != 0)
return true;
return false;
}
/*
* Can be changed by subclass
*/
protected int convSingleByte(char inputChar, byte[] outputByte) {
if (inputChar < 0x80) {
outputByte[0] = (byte)(inputChar & 0x7f);
return 1;
}
return 0;
}
/*
* Can be changed by subclass
*/
protected int getNative(char ch) {
int offset = index1[((ch & 0xff00) >> 8 )] << 8;
return index2[offset >> 12].charAt((offset & 0xfff) + (ch & 0xff));
}
}