前阵子接触了php对接java服务端TCP接口，这是工作一年以来第一次对接，还是php对接java。使用的是socket。

技术点概括：

代码整理：

class BlowFish
{
    public $xmlObj;
    public $xmlMsg;

    //获取bf算法的key
    public function make_openssl_blowfish_key($key)
    {
        if ("$key" === '')
            return $key;

        $len = (16 + 2) * 4;
        while (strlen($key) < $len) {
            $key .= $key;
        }
        $key = substr($key, 0, $len);
        return $key;
    }

    //字符填充
    public function padding($str)
    {
        $blockSize = 8;
        $len = strlen($str);
        $paddingLen = intval(($len + $blockSize - 1) / $blockSize) * $blockSize - $len;
        $padding = str_repeat("\0", $paddingLen);
        $data = $str . $padding;
        return $data;
    }

    //16进制转byte数组
    public function hex2ByteArray($hexString)
    {
        $string = hex2bin($hexString);
        return unpack('C*', $string);
    }

    //字节数组转字节流
    public function byteToByteStr($bytes)
    {
        $str = '';
        foreach ($bytes as $ch) {
            $str .= chr($ch);
        }
        return $str;
    }

    //字节流转16进制
    public function string2Hex($string)
    {
        return bin2hex($string);
    }

    //blowfish解密算法
    public function openssl_blowfish_decrypt_hex($key, $hex)
    {
        $key = $this->make_openssl_blowfish_key($key);
        $decrypted = openssl_decrypt(hex2bin($hex), 'BF-ECB', $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING);
        return rtrim($decrypted, "\0");
    }

    //头部报文长度计算，经过填充才计算消息长度
    public function headConvertByte($str)
    {
        $new = $this->padding($str);
        $len = mb_strlen($new, "UTF8");
        $string = "00000000" . dechex($len);
        //返回最后8个字符
        $lastString = substr($string, mb_strlen($string, "UTF8") - 8);

        $bindata = '';
        //每两位转换为16进制
        for ($i = mb_strlen($lastString, "UTF8"); $i >= 2; $i -= 2) {
            $bindata .= strtoupper(substr($lastString, $i - 2, 2));
        }

        return $bindata;
    }

    //bf加密，如果位数不够，则填充
    public function openssl_blowfish_encrypt_hex($key, $str)
    {
        $data = $this->padding($str);
        $key = $this->make_openssl_blowfish_key($key);
        $encrypted = openssl_encrypt($data, 'BF-ECB', $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING);
        return bin2hex($encrypted);
    }

    //设置XML对象,参数为string
    public function setXml($string, $array)
    {
        $this->xmlObj = new SimpleXMLElement($string);
        return $this->setXmlChild($this->xmlObj, $array);
    }

    //设置XML消息体,传入二维数组
    public function setXmlChild($xmlObj, array $array = [])
    {
        if (!$this->xmlObj instanceof SimpleXMLElement) {
            return false;
        }
        return $this->addChildXml($xmlObj, $array);
    }
    
    //支持无限嵌套的xml生成
    public function addChildXml($xmlObj, $array)
    {
        foreach ($array as $k => $value) {
            if (!is_array($value)) {
                $xmlObj->addchild($k, $value);
            } else if (is_array($value)) {
                $this->setXmlChild($xmlObj->addchild($k), $value);
            }
        }
        return $xmlObj;
    }


    //截断XML表格头部，生成socket消息体
    public function delXmlTableHead()
    {
        if ($this->xmlObj->asXml() && is_string($this->xmlObj->asXml())) {
            $start = strpos($this->xmlObj->asXml(), 'message');
            return $this->xmlMsg = trim('<' . substr($this->xmlObj->asXml(), $start));
        }
        return false;
    }

    //处理并解密字节流
    public function convertSocketByteToPlaintext($byteString, $apiSecret)
    {
        $hex = $this->string2Hex($byteString);
        $hexNew = substr($hex, 8);
        return $this->openssl_blowfish_decrypt_hex($apiSecret, $hexNew);
    }
}

由于我的自定义协议是xml，因此上面代码中封装了xml的生成，有需要生成XML的可以拿过去使用。

swoole关于粘包/拆包，小端模式以及缓冲区的设置：

以上是此次对接主要的场景