字节工具

来源：互联网发布：nginx ssl配置详解编辑：程序博客网时间：2024/05/17 04:02
public class BytesUtil {    public static char[] hex = "0123456789ABCDEF".toCharArray();    public static String bytesToHexStr(byte... bytes) {        char[] result = new char[bytes.length * 2];        int resultIndex;        for (int i = 0; i < bytes.length; i++) {            resultIndex = 2 * i;            result[resultIndex] = hex[(bytes[i] >> 4) & 0x0F];            result[resultIndex + 1] = hex[bytes[i] & 0x0F];        }        return new String(result);    }    public static byte[] hexStrToBytes(String byteStr) {        if (byteStr == null) {            return null;        }        if (byteStr.length() % 2 != 0) {            throw new RuntimeException("byteStr长度不是偶数，没法转");        }        int resultLen = byteStr.length() / 2;        byte[] result = new byte[resultLen];        char h, l;        byte b;        byteStr = byteStr.toUpperCase();        int strIndex;        for (int i = 0; i < resultLen; i++) {            strIndex = 2 * i;            h = byteStr.charAt(strIndex);            if ('0' <= h && h <= '9') {                b = (byte) ((h - '0') << 4);            } else if ('A' <= h && h <= 'F') {                b = (byte) ((h - 'A' + 10) << 4);            } else {                throw new RuntimeException("byteStr 的第" + i + "个字符 不在16进制范围中");            }            l = byteStr.charAt(strIndex + 1);            if ('0' <= l && l <= '9') {//                b |= (byte) (0x0F & (l - '0'));                b |= (byte) (l - '0');            } else if ('A' <= l && l <= 'F') {//                b |= (byte) (0x0F & (l - 'A' + 10));                b |= (byte) (l - 'A' + 10);            } else {                throw new RuntimeException("byteStr 的第" + (i + 1) + "个字符 不在16进制范围中");            }            result[i] = b;        }        return result;    }}
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