Java sends a POST request

      Access preparation URL url = new URL ("http:***");            Post parameters map<string,object> params = new linkedhashmap<> ();            Params.put ("Geominfo", "" ");       Params.put ("F", "JSON");        Start Access StringBuilder postdata = new StringBuilder (); For (map.entry<string,object> Param:params.entrySet ()) {if (Postdata.length ()! = 0) postdata.append (' &            amp; ');            Postdata.append (Urlencoder.encode (Param.getkey (), "UTF-8"));            Postdata.append (' = ');        Postdata.append (Urlencoder.encode (string.valueof (Param.getvalue ()), "UTF-8"));        } byte[] Postdatabytes = postdata.tostring (). GetBytes ("UTF-8");        HttpURLConnection conn = (httpurlconnection) url.openconnection ();        Conn.setrequestmethod ("POST");        Conn.setrequestproperty ("Content-type", "application/x-www-form-urlencoded");        Conn.setrequestproperty ("Content-length", String.valueof (Postdatabytes.length));  Conn.setdooutput (TRUE);      Conn.getoutputstream (). write (postdatabytes);        Reader in = new BufferedReader (New InputStreamReader (Conn.getinputstream (), "UTF-8"));        StringBuilder sb = new StringBuilder (); for (int c;        (c = in.read ()) >= 0;) sb.append ((char) c);        String response = sb.tostring ();        SYSTEM.OUT.PRINTLN (response);         return response;

　　

Java sends a POST request