Java Hex Convert To fromHexString(String s)

Description

from Hex String

License

Apache License

Declaration

public static byte[] fromHexString(String s) 

Method Source Code

//package com.java2s;
// Licensed under the Apache License, Version 2.0 (the "License");

public class Main {
    public static byte[] fromHexString(String s) {
        if (s.length() % 2 != 0)
            throw new IllegalArgumentException(s);
        byte[] array = new byte[s.length() / 2];
        for (int i = 0; i < array.length; i++) {
            int b = Integer.parseInt(s.substring(i * 2, i * 2 + 2), 16);
            array[i] = (byte) (0xff & b);
        }/*  w  w  w . ja  va 2s . c o  m*/
        return array;
    }

    /** Parse an int from a substring.
     * Negative numbers are not handled.
     * @param s String
     * @param offset Offset within string
     * @param length Length of integer or -1 for remainder of string
     * @param base base of the integer
     * @exception NumberFormatException 
     */
    public static int parseInt(String s, int offset, int length, int base) throws NumberFormatException {
        int value = 0;

        if (length < 0)
            length = s.length() - offset;

        for (int i = 0; i < length; i++) {
            char c = s.charAt(offset + i);

            int digit = c - '0';
            if (digit < 0 || digit >= base || digit >= 10) {
                digit = 10 + c - 'A';
                if (digit < 10 || digit >= base)
                    digit = 10 + c - 'a';
            }
            if (digit < 0 || digit >= base)
                throw new NumberFormatException(s.substring(offset, offset + length));
            value = value * base + digit;
        }
        return value;
    }

    /** Parse an int from a byte array of ascii characters.
     * Negative numbers are not handled.
     * @param b byte array
     * @param offset Offset within string
     * @param length Length of integer or -1 for remainder of string
     * @param base base of the integer
     * @exception NumberFormatException 
     */
    public static int parseInt(byte[] b, int offset, int length, int base) throws NumberFormatException {
        int value = 0;

        if (length < 0)
            length = b.length - offset;

        for (int i = 0; i < length; i++) {
            char c = (char) (0xff & b[offset + i]);

            int digit = c - '0';
            if (digit < 0 || digit >= base || digit >= 10) {
                digit = 10 + c - 'A';
                if (digit < 10 || digit >= base)
                    digit = 10 + c - 'a';
            }
            if (digit < 0 || digit >= base)
                throw new NumberFormatException(new String(b, offset, length));
            value = value * base + digit;
        }
        return value;
    }
}

Related

1. fromHexString(String input)
2. fromHexString(String input)
3. fromHexString(String s)
4. fromHexString(String s)
5. fromHexString(String s)
6. fromHexString(String s)
7. fromHexString(String s)
8. fromHexString(String s)
9. fromHexString(String s)