com.iohao.game.common.kit.adapter.HuBase16Codec Maven / Gradle / Ivy
package com.iohao.game.common.kit.adapter;
/**
* @author 渔民小镇
* @date 2023-01-19
*/
class HuBase16Codec {
private final char[] alphabets;
public HuBase16Codec(boolean lowerCase) {
this.alphabets = (lowerCase ? "0123456789abcdef" : "0123456789ABCDEF").toCharArray();
}
public char[] encode(byte[] data) {
final int len = data.length;
final char[] out = new char[len << 1];
//len*2
// two characters from the hex value.
for (int i = 0, j = 0; i < len; i++) {
out[j++] = alphabets[(0xF0 & data[i]) >>> 4];
// 高位
out[j++] = alphabets[0x0F & data[i]];
// 低位
}
return out;
}
public byte[] decode(CharSequence encoded) {
if (HuStrUtil.isEmpty(encoded)) {
return new byte[0];
}
encoded = HuStrUtil.cleanBlank(encoded);
int len = encoded.length();
if ((len & 0x01) != 0) {
// 如果提供的数据是奇数长度，则前面补0凑偶数
encoded = "0" + encoded;
len = encoded.length();
}
final byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++) {
int f = toDigit(encoded.charAt(j), j) << 4;
j++;
f = f | toDigit(encoded.charAt(j), j);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
public void appendHex(StringBuilder builder, byte b) {
int high = (b & 0xf0) >>> 4;
int low = b & 0x0f;
builder.append(alphabets[high]);
builder.append(alphabets[low]);
}
private static int toDigit(char ch, int index) {
int digit = Character.digit(ch, 16);
if (digit < 0) {
throw new HuUtilException("Illegal hexadecimal character {} at index {}", ch, index);
}
return digit;
}
}