Decode hex string to a byte array : Byte Array « File « Java Tutorial





/*
 * 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.
 */


/**
 * format validation
 *
 * This class encodes/decodes hexadecimal data
 * 
 * @xerces.internal  
 * 
 * @author Jeffrey Rodriguez
 * @version $Id: HexBin.java 446747 2006-09-15 21:46:20Z mrglavas $
 */
public final class  HexBin {
    static private final int  BASELENGTH   = 128;
    static private final int  LOOKUPLENGTH = 16;
    static final private byte [] hexNumberTable    = new byte[BASELENGTH];
    static final private char [] lookUpHexAlphabet = new char[LOOKUPLENGTH];


    static {
        for (int i = 0; i < BASELENGTH; i++ ) {
            hexNumberTable[i] = -1;
        }
        for ( int i = '9'; i >= '0'; i--) {
            hexNumberTable[i] = (byte) (i-'0');
        }
        for ( int i = 'F'; i>= 'A'; i--) {
            hexNumberTable[i] = (byte) ( i-'A' + 10 );
        }
        for ( int i = 'f'; i>= 'a'; i--) {
           hexNumberTable[i] = (byte) ( i-'a' + 10 );
        }

        for(int i = 0; i<10; i++ ) {
            lookUpHexAlphabet[i] = (char)('0'+i);
        }
        for(int i = 10; i<=15; i++ ) {
            lookUpHexAlphabet[i] = (char)('A'+i -10);
        }
    }

    /**
     * Decode hex string to a byte array
     *
     * @param encoded encoded string
     * @return return array of byte to encode
     */
    static public byte[] decode(String encoded) {
        if (encoded == null)
            return null;
        int lengthData = encoded.length();
        if (lengthData % 2 != 0)
            return null;

        char[] binaryData = encoded.toCharArray();
        int lengthDecode = lengthData / 2;
        byte[] decodedData = new byte[lengthDecode];
        byte temp1, temp2;
        char tempChar;
        for( int i = 0; i<lengthDecode; i++ ){
            tempChar = binaryData[i*2];
            temp1 = (tempChar < BASELENGTH) ? hexNumberTable[tempChar] : -1;
            if (temp1 == -1)
                return null;
            tempChar = binaryData[i*2+1];
            temp2 = (tempChar < BASELENGTH) ? hexNumberTable[tempChar] : -1;
            if (temp2 == -1)
                return null;
            decodedData[i] = (byte)((temp1 << 4) | temp2);
        }
        return decodedData;
    }
}










11.77.Byte Array
11.77.1.Load file to byte array
11.77.2.Load File as byte array
11.77.3.Convert Byte array to Int
11.77.4.Gets an array of bytes corresponding to the given object
11.77.5.Convert byte array to string
11.77.6.An optimized reader for reading byte streams that only contain 7-bit ASCII characters.
11.77.7.Convert a base16 string into a byte array.
11.77.8.Convert a byte array to a human-readable String for debugging purposes.
11.77.9.Convert the bytes within the specified range of the given byte array into a String
11.77.10.Convert the bytes within the specified range of the given byte array into a signed integer in the given radix
11.77.11.Converts a byte array into a hexadecimal string
11.77.12.Converts a byte array into hexadecimal characters which are written as ASCII to the given output stream.
11.77.13.Decode hex string to a byte array
11.77.14.Encode a byte array to hex string
11.77.15.Get bytes from InputStream
11.77.16.Read and return the entire contents of the supplied file.
11.77.17.Reads bytes available from one InputStream and returns these bytes in a byte array.
11.77.18.Return the specified class. Checks the ThreadContext classloader first, then uses the System classloader.
11.77.19.Translates between byte arrays and strings of "0"s and "1"s.