Android ASCII to Byte Array Convert fromAscii(char[] ascii)

Description

Decodes a byte array where each char represents an ascii '0' or '1'.

License

Apache License

Parameter

Parameter	Description
ascii	each char represents an ascii '0' or '1'

Return

the raw encoded binary where each bit corresponds to a char in the char array argument

Declaration

public static byte[] fromAscii(char[] ascii) 

Method Source Code

/*/*  www  .  j  av  a 2  s  . c  om*/
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed 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.
 */

import org.apache.commons.codec.BinaryDecoder;
import org.apache.commons.codec.BinaryEncoder;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.EncoderException;

public class Main{
    /** Empty byte array. */
    private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
    private static final int[] BITS = { BIT_0, BIT_1, BIT_2, BIT_3, BIT_4,
            BIT_5, BIT_6, BIT_7 };
    /**
     * Decodes a byte array where each char represents an ascii '0' or '1'.
     * 
     * @param ascii
     *                  each char represents an ascii '0' or '1'
     * @return the raw encoded binary where each bit corresponds to a char in the char array argument
     */
    public static byte[] fromAscii(char[] ascii) {
        if (ascii == null || ascii.length == 0) {
            return EMPTY_BYTE_ARRAY;
        }
        // get length/8 times bytes with 3 bit shifts to the right of the length
        byte[] l_raw = new byte[ascii.length >> 3];
        /*
         * We decr index jj by 8 as we go along to not recompute indices using multiplication every time inside the
         * loop.
         */
        for (int ii = 0, jj = ascii.length - 1; ii < l_raw.length; ii++, jj -= 8) {
            for (int bits = 0; bits < BITS.length; ++bits) {
                if (ascii[jj - bits] == '1') {
                    l_raw[ii] |= BITS[bits];
                }
            }
        }
        return l_raw;
    }
    /**
     * Decodes a byte array where each byte represents an ascii '0' or '1'.
     * 
     * @param ascii
     *                  each byte represents an ascii '0' or '1'
     * @return the raw encoded binary where each bit corresponds to a byte in the byte array argument
     */
    public static byte[] fromAscii(byte[] ascii) {
        if (ascii == null || ascii.length == 0) {
            return EMPTY_BYTE_ARRAY;
        }
        // get length/8 times bytes with 3 bit shifts to the right of the length
        byte[] l_raw = new byte[ascii.length >> 3];
        /*
         * We decr index jj by 8 as we go along to not recompute indices using multiplication every time inside the
         * loop.
         */
        for (int ii = 0, jj = ascii.length - 1; ii < l_raw.length; ii++, jj -= 8) {
            for (int bits = 0; bits < BITS.length; ++bits) {
                if (ascii[jj - bits] == '1') {
                    l_raw[ii] |= BITS[bits];
                }
            }
        }
        return l_raw;
    }
}

Related

1. fromAscii(byte[] ascii)