function strToUtf8Bytes(str) {
    const utf8 = [];
    for (let ii = 0; ii < str.length; ii++) {
        let charCode = str.charCodeAt(ii);
        if (charCode < 0x80) utf8.push(charCode);
        else if (charCode < 0x800) {
            utf8.push(0xc0 | (charCode >> 6), 0x80 | (charCode & 0x3f));
        } else if (charCode < 0xd800 || charCode >= 0xe000) {
            utf8.push(0xe0 | (charCode >> 12), 0x80 | ((charCode >> 6) & 0x3f), 0x80 | (charCode & 0x3f));
        } else {
            ii++;
            charCode = 0x10000 + (((charCode & 0x3ff) << 10) | (str.charCodeAt(ii) & 0x3ff));
            utf8.push(
                0xf0 | (charCode >> 18),
                0x80 | ((charCode >> 12) & 0x3f),
                0x80 | ((charCode >> 6) & 0x3f),
                0x80 | (charCode & 0x3f),
            );
        }
    }
    //兼容汉字，ASCII码表最大的值为127，大于127的值为特殊字符
    for (let jj = 0; jj < utf8.length; jj++) {
        var code = utf8[jj];
        if (code > 127) {
            utf8[jj] = code - 256;
        }
    }
    return utf8;
}

function strToHexCharCode(str) {
    var hexCharCode = [];
    var chars = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"];
    for (var i = 0; i < str.length; i++) {
        var bit = (str[i] & 0x0f0) >> 4;
        hexCharCode.push(chars[bit]);
        var bit = str[i] & 0x0f;
        hexCharCode.push(chars[bit]);
    }
    return hexCharCode.join("");
}

function hexCharCodeToStr(hex) {
    var arr = hex.split("")
    var out = ""
    for (var i = 0; i < arr.length / 2; i++) {
        var tmp = "0x" + arr[i * 2] + arr[i * 2 + 1]
        var charValue = String.fromCharCode(tmp);
        out += charValue
    }
    return decodeURIComponent(escape(out))
}

let str = '测试123abc';

// 字符串转16进制
console.log(strToHexCharCode(strToUtf8Bytes(str))); // 输出 E6B58BE8AF95313233616263
// 16进制转字符串
console.log(hexCharCodeToStr('E6B58BE8AF95313233616263')); // 输出 测试123abc