Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

public class Main {
    /**
     * Convert a string containing hexadecimal characters to a byte-array.
     *
     * @param s a hex string
     * @return a byte array with the corresponding value
     */
    public static byte[] fromHexString(String s) {
        char[] rawChars = s.toUpperCase().toCharArray();

        int hexChars = 0;
        for (int i = 0; i < rawChars.length; i++) {
            if ((rawChars[i] >= '0' && rawChars[i] <= '9') || (rawChars[i] >= 'A' && rawChars[i] <= 'F')) {
                hexChars++;
            }
        }

        byte[] byteString = new byte[(hexChars + 1) >> 1];

        int pos = hexChars & 1;

        for (int i = 0; i < rawChars.length; i++) {
            if (rawChars[i] >= '0' && rawChars[i] <= '9') {
                byteString[pos >> 1] <<= 4;
                byteString[pos >> 1] |= rawChars[i] - '0';
            } else if (rawChars[i] >= 'A' && rawChars[i] <= 'F') {
                byteString[pos >> 1] <<= 4;
                byteString[pos >> 1] |= rawChars[i] - 'A' + 10;
            } else {
                continue;
            }
            pos++;
        }

        return byteString;
    }

    /**
     * Rewrite a byte array as a char array
     *
     * @param input -
     *              the byte array
     * @return char array
     */
    public static char[] toCharArray(byte[] input) {
        char[] result = new char[input.length];
        for (int i = 0; i < input.length; i++) {
            result[i] = (char) input[i];
        }
        return result;
    }
}