/*
* Copyright 1999-2012 Alibaba Group.
*
* 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.
*/
package com.alibaba.cobar.parser.util;
/**
* @author xianmao.hexm
*/
public final class ParseString {
private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
public static byte[] hexString2Bytes(char[] hexString, int offset, int length) {
if (hexString == null)
return null;
if (length == 0)
return EMPTY_BYTE_ARRAY;
boolean odd = length << 31 == Integer.MIN_VALUE;
byte[] bs = new byte[odd ? (length + 1) >> 1 : length >> 1];
for (int i = offset, limit = offset + length; i < limit; ++i) {
char high, low;
if (i == offset && odd) {
high = '0';
low = hexString[i];
} else {
high = hexString[i];
low = hexString[++i];
}
int b;
switch (high) {
case '0':
b = 0;
break;
case '1':
b = 0x10;
break;
case '2':
b = 0x20;
break;
case '3':
b = 0x30;
break;
case '4':
b = 0x40;
break;
case '5':
b = 0x50;
break;
case '6':
b = 0x60;
break;
case '7':
b = 0x70;
break;
case '8':
b = 0x80;
break;
case '9':
b = 0x90;
break;
case 'a':
case 'A':
b = 0xa0;
break;
case 'b':
case 'B':
b = 0xb0;
break;
case 'c':
case 'C':
b = 0xc0;
break;
case 'd':
case 'D':
b = 0xd0;
break;
case 'e':
case 'E':
b = 0xe0;
break;
case 'f':
case 'F':
b = 0xf0;
break;
default:
throw new IllegalArgumentException("illegal hex-string: " + new String(hexString, offset, length));
}
switch (low) {
case '0':
break;
case '1':
b += 1;
break;
case '2':
b += 2;
break;
case '3':
b += 3;
break;
case '4':
b += 4;
break;
case '5':
b += 5;
break;
case '6':
b += 6;
break;
case '7':
b += 7;
break;
case '8':
b += 8;
break;
case '9':
b += 9;
break;
case 'a':
case 'A':
b += 10;
break;
case 'b':
case 'B':
b += 11;
break;
case 'c':
case 'C':
b += 12;
break;
case 'd':
case 'D':
b += 13;
break;
case 'e':
case 'E':
b += 14;
break;
case 'f':
case 'F':
b += 15;
break;
default:
throw new IllegalArgumentException("illegal hex-string: " + new String(hexString, offset, length));
}
bs[(i - offset) >> 1] = (byte) b;
}
return bs;
}
}