Android socket connection loses after app being idle for some time -

my application listens socket. application connected socket using following method.

public void connect() {     this.connectionstatus = connect_status_connecting;     log.v(appconstants.debug_tag, userid + " : connecting server");     if (mthread != null && mthread.isalive()) {         return;     }     mthread = new thread(new runnable() {         @override         public void run() {             try {                 log.v(appconstants.debug_tag, userid + " : thread action started");                 string secret = createsecret();                  int port = (muri.getport() != -1) ? muri.getport() : (muri.getscheme().equals("wss") ? 443 : 80);                  string path = textutils.isempty(muri.getpath()) ? "/" : muri.getpath();                 if (!textutils.isempty(muri.getquery())) {                     path += "?" + muri.getquery();                 }                 string originscheme = muri.getscheme().equals("wss") ? "https" : "http";                 uri origin = new uri(originscheme, "//" + muri.gethost(), null);                  socketfactory factory = muri.getscheme().equals("wss") ? getsslsocketfactory() : socketfactory.getdefault();                 msocket = factory.createsocket(muri.gethost(), port);                   printwriter out = new printwriter(msocket.getoutputstream());                 out.print("get " + path + " http/1.1\r\n");                 out.print("upgrade: websocket\r\n");                 out.print("connection: upgrade\r\n");                 out.print("host: " + muri.gethost() + "\r\n");                 out.print("origin: " + origin.tostring() + "\r\n");                 out.print("sec-websocket-key: " + secret + "\r\n");                 out.print("sec-websocket-version: 13\r\n");                 if (mextraheaders != null) {                     (namevaluepair pair : mextraheaders) {                         out.print(string.format("%s: %s\r\n", pair.getname(), pair.getvalue()));                     }                 }                 out.print("\r\n");                 out.flush();                  hybiparser.happydatainputstream stream = new hybiparser.happydatainputstream(msocket.getinputstream());                  // read http response status line.                 statusline statusline = parsestatusline(readline(stream));                 if (statusline == null) {                     log.v(appconstants.debug_tag, "received no reply server.");                     throw new httpexception("received no reply server.");                 } else if (statusline.getstatuscode() != httpstatus.sc_switching_protocols) {                     throw new httpresponseexception(statusline.getstatuscode(), statusline.getreasonphrase());                 }                  // read http response headers.                 string line;                 boolean validated = false;                  while (!textutils.isempty(line = readline(stream))) {                     header header = parseheader(line);                     if (header.getname().equals("sec-websocket-accept")) {                         string expected = createsecretvalidation(secret);                         string actual = header.getvalue().trim();                          if (!expected.equals(actual)) {                             log.v(appconstants.debug_tag, "bad sec-websocket-accept header value.");                             throw new httpexception("bad sec-websocket-accept header value.");                         }                         validated = true;                     }                 }                  if (!validated) {                     log.v(appconstants.debug_tag, "no sec-websocket-accept header.");                     throw new httpexception("no sec-websocket-accept header.");                 }                 onconnect();                 log.v(appconstants.debug_tag, userid + " : thread should connected now");                 // decode websocket frames.                 mparser.start(stream);             } catch (eofexception ex) {                 log.d(appconstants.debug_tag, "websocket eof!", ex);                 ondisconnect(0, "eof");             } catch (sslexception ex) {                 // connection reset peer                 log.d(appconstants.debug_tag, "websocket ssl error!", ex);                 ondisconnect(0, "ssl");             } catch (exception ex) {                 onerror(ex);             }         }     });     log.v(appconstants.debug_tag, userid + " : thread started");     mthread.start(); } 

here problem when leave application 15 or more idle, connection automatically closes , app becomes unusable.what reason behind , how resolve this?

probably, server closes idle connection. send ping (or pong) periodically keep connection.

btw, guess code based on open-source websocket library. if so, note not of commercial quality. not perform closing handshake on disconnect().