Java: send POST HTTP request to upload a file to MediaFire REST API -

i need send http post request mediafire rest api java web app running in google app engine, in order upload file.

please see upload function documentation here (few lines).

looking @ documentation , research, i've written following java code make correspondent request:

byte[] bytesdata = //byte array file data  url url = new url("http://www.mediafire.com/api/upload/upload.php?" +                     "session_token=" + sessiontoken);  //configure connection httpurlconnection conn = (httpurlconnection) url.openconnection(); conn.setdooutput(true); conn.setrequestmethod("post"); conn.setreadtimeout(60000);  //set headers conn.setrequestproperty("content-type", "application/octet-stream"); conn.setrequestproperty("x-filename", filename); conn.setrequestproperty("x-filesize", filesize); conn.setrequestproperty("x-filehash", sha256);  //write binary data system.out.println("\nwriting data..."); outputstream out = conn.getoutputstream(); out.write(bytesdata); out.flush();  //check connection //if (conn.getresponsecode() != httpurlconnection.http_created) { //  throw new runtimeexception("failed!!! http error code: " +  //                             conn.getresponsecode() + " --- " +  //                             conn.getresponsemessage()); //}  //get response system.out.println("\ngetting response..."); bufferedreader br = new bufferedreader(new inputstreamreader(conn.getinputstream()));  //print response system.out.println("\noutput server .... \n"); string output; while ((output = br.readline()) != null) {   system.out.println(output); } 

but i'm not getting result, just:

writing data... getting response... output server: 

if un-comment lines under //check connection exception:

java.lang.runtimeexception: failed!!! http error code: 503 --- ok 

if change content-type header multipart/form-data different exception:

java.lang.runtimeexception: failed!!! http error code: 400 --- ok 

i don't know http connections , on , have no idea what's happening...

any ideas may going on?

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note: i'm using other (get) methods of api same app , working perfectly.

http error code: 400 status code bad request, means server not except multipart/form-data, 503 code means server overloaded, service may hosted on different server/thread on server other methods, may receiving more traffic.