Return the Unicode char which is coded in the bytes at the given position.
import java.io.File;
import java.io.FileFilter;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
/**
* Various string manipulation methods that are more efficient then chaining
* string operations: all is done in the same buffer without creating a bunch of
* string objects.
*
* @author <a href="mailto:dev@labs.apache.org">Dungeon Project</a>
*/
public class Main {
private static final int CHAR_ONE_BYTE_MASK = 0xFFFFFF80;
private static final int CHAR_TWO_BYTES_MASK = 0xFFFFF800;
private static final int CHAR_THREE_BYTES_MASK = 0xFFFF0000;
private static final int CHAR_FOUR_BYTES_MASK = 0xFFE00000;
private static final int CHAR_FIVE_BYTES_MASK = 0xFC000000;
private static final int CHAR_SIX_BYTES_MASK = 0x80000000;
/**
* Return the Unicode char which is coded in the bytes at the given
* position.
*
* @param car The character to be transformed to an array of bytes
*
* @return The byte array representing the char
*
* TODO : Should stop after the third byte, as a char is only 2 bytes long.
*/
public static final byte[] charToBytes( char car )
{
byte[] bytes = new byte[countNbBytesPerChar( car )];
if ( ( car | 0x7F ) == 0x7F )
{
// Single byte char
bytes[0] = ( byte ) car;
return bytes;
}
else if ( ( car | 0x7F) == 0x7FF )
{
// two bytes char
bytes[0] = ( byte ) ( 0x00C0 + ( ( car & 0x07C0 ) >> 6 ) );
bytes[1] = ( byte ) ( 0x0080 + ( car & 0x3F ) );
}
else
{
// Three bytes char
bytes[0] = ( byte ) ( 0x00E0 + ( ( car & 0xF000 ) >> 12 ) );
bytes[1] = ( byte ) ( 0x0080 + ( ( car & 0x0FC0 ) >> 6 ) );
bytes[2] = ( byte ) ( 0x0080 + ( car & 0x3F ) );
}
return bytes;
}
/**
* Return the number of bytes that hold an Unicode char.
*
* @param car
* The character to be decoded
* @return The number of bytes to hold the char. TODO : Should stop after
* the third byte, as a char is only 2 bytes long.
*/
public static final int countNbBytesPerChar( char car )
{
if ( ( car & CHAR_ONE_BYTE_MASK ) == 0 )
{
return 1;
}
else if ( ( car & CHAR_TWO_BYTES_MASK ) == 0 )
{
return 2;
}
else if ( ( car & CHAR_THREE_BYTES_MASK ) == 0 )
{
return 3;
}
else if ( ( car & CHAR_FOUR_BYTES_MASK ) == 0 )
{
return 4;
}
else if ( ( car & CHAR_FIVE_BYTES_MASK ) == 0 )
{
return 5;
}
else if ( ( car & CHAR_SIX_BYTES_MASK ) == 0 )
{
return 6;
}
else
{
return -1;
}
}
}
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