Http simulate Form form submit POST request

private static Logger log = Loggerfactory.getlogger (Httppostutil.class); public static string Reqxinyi (string url, string appkey,string data,string sign) throws ioexception{Objectmapper Ma
    Pper = new Objectmapper ();
    String param= null;
    String B = null; try {param = "appkey=" + urlencoder.encode (Appkey, "UTF-8") + "&data=" +urlencoder.encode (data, "UTF-8") + "&si
        gn= "+urlencoder.encode (sign," UTF-8 ");
    Log.info ("Stitching request parameter param:" +param);
        catch (Unsupportedencodingexception e) {log.error ("stitching request parameter Error");
    E.printstacktrace ();
        } log.info ("Start sending request");
        URL url = new URL (URLs);
        URLConnection connection = Url.openconnection ();
        HttpURLConnection httpconn = (httpurlconnection) connection;
        Set the request method to post Httpconn.setrequestmethod ("POST");
        Sets whether the output Httpconn.setdooutput (true) is required;
        Sets whether you want to allow input httpconn.setdoinput (true); Set request Properties Httpconn.setrequestproPerty ("Content-length", String.valueof (Param.getbytes (). Length));
        Httpconn.setrequestproperty ("Content-type", "application/x-www-form-urlencoded;charset=utf-8");
        Write data to server outputstream out = Httpconn.getoutputstream ();
        Out.write (Param.getbytes ("UTF-8"));
        Out.close ();
        The data returned by the receiving server InputStream in = Httpconn.getinputstream ();
        Bytearrayoutputstream resp = new Bytearrayoutputstream ();
        byte[] tempbytes = new byte[100];
        int byteread = 0;
        while ((Byteread = In.read (tempbytes))!=-1) {resp.write (tempbytes, 0, Byteread);
        } B = New String (Resp.tobytearray ());
        Log.info ("Call interface return: {}", b);
return b;
 }