chartobyteiso8859_1.java

来自「This is a resource based on j2me embedde」· Java 代码 · 共 203 行

/*
 * @(#)CharToByteISO8859_1.java	1.28 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;

public class CharToByteISO8859_1 extends CharToByteConverter {

    // Return the character set ID
    public String getCharacterEncoding()
    {
        return "ISO8859_1";
    }

    private char highHalfZoneCode;
    
    public int flush(byte[] output, int outStart, int outEnd)
	throws MalformedInputException
    {
	if (highHalfZoneCode != 0) {
	    highHalfZoneCode = 0;
	    throw new MalformedInputException
		("String ends with <High Half Zone code> of UTF16");
	}
	byteOff = charOff = 0;
	return 0;
    }

    /*
    * Character conversion
    */
    public native int convert(char[] input, int inOff, int inEnd,
                              byte[] output, int outOff, int outEnd)
        throws MalformedInputException,
               UnknownCharacterException,
               ConversionBufferFullException;

    /**
    * This method is changed to a CNI method 
    * for performance purpose.
    *
    *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
    *    int     outputSize;         // Size of output
    *
    *    // Record beginning offsets
    *    charOff = inOff;
    *    byteOff = outOff;
    *
    *    if (highHalfZoneCode != 0) {
    *        highHalfZoneCode = 0;
    *        if (input[inOff] >= 0xdc00 && input[inOff] <= 0xdfff) {
    *            // This is legal UTF16 sequence.
    *            if (subMode) {
    *                outputSize = subBytes.length;
    *                if (byteOff + outputSize > outEnd)
    *                    throw new ConversionBufferFullException();
    *                System.arraycopy(subBytes, 0, output, byteOff, outputSize);
    *                byteOff += outputSize;
    *                charOff += 1;
    *            } else {
    *                badInputLength = 1;
    *                throw new UnknownCharacterException();
    *            }
    *        } else {
    *            // This is illegal UTF16 sequence.
    *            badInputLength = 0;
    *            throw new MalformedInputException
    *                ("Previous converted string ends with " +
    *                 "<High Half Zone Code> of UTF16 " +
    *                 ", but this string is not begin with <Low Half Zone>");
    *        }
    *    }
    *
    *    // Loop until we hit the end of the input
    *    while(charOff < inEnd) {
    *        // Get the input character
    *        inputChar = input[charOff];
    *
    *        // Is this character mappable?
    *       if (inputChar <= '\u00FF') {
    *           if (byteOff + 1 > outEnd)
    *              throw new ConversionBufferFullException();
    *
    *           output[byteOff++] = (byte)inputChar;
    *          charOff += 1;
    *       }
    *        // Is this a high surrogate?
    *        else if(inputChar >= '\uD800' && inputChar <= '\uDBFF') {
    *            // Is this the last character in 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 map
    *                //  surrogates.  Is substitution enabled?
    *                if (subMode) {
    *                    outputSize = subBytes.length;
    *
    *                    if (byteOff + outputSize > outEnd)
    *                        throw new ConversionBufferFullException();
    *
    *                    System.arraycopy(subBytes, 0, output, byteOff, outputSize);
    *                    byteOff += outputSize;
    *                    charOff += 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();
    *        }
    *        // Unmappable and not part of a surrogate
    *        else {
    *            // Is substitution enabled?
    *            if (subMode) {
    *                outputSize = subBytes.length;
    *
    *                if (byteOff + outputSize > outEnd)
    *                    throw new ConversionBufferFullException();
    *
    *                System.arraycopy(subBytes, 0, output, byteOff, outputSize);
    *                byteOff += outputSize;
    *                charOff += 1;
    *
    *            } else {
    *                badInputLength = 1;
    *                throw new UnknownCharacterException();
    *            }
    *        }
    *    }
    *
    *    // Return the length written to the output buffer
    *    return byteOff-outOff;
    *}
    */ 

    // Determine if a character is mappable or not
    public boolean canConvert(char ch)
    {
        return (ch <= '\u00FF');
    }

    // Reset the converter
    public void reset()
    {
	byteOff = charOff = 0;
	highHalfZoneCode = 0;
    }

    /**
    * returns the maximum number of bytes needed to convert a char
    */
    public int getMaxBytesPerChar()
    {
        return 1;
    }


}