java - Existing TCP socket class throw NetworkOnMainThreadException when updated to new API -

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• how fix android.os.networkonmainthreadexception? 44 answers

i have inherited android application , updating latest api. getting networkonmainthreadexception when create socket. have read number of solutions use asynctask. asynctask should used short running tasks. standard tcp connection last life of running application. bi-directional.

how dod update class using threads don't exception , able send data on socket?

public class tcpconnection {     enum state {     closed,     closing,     open };  state _state;     socket _socket; //data stream head-unit datainputstream _inputstream; //data stream head-unit dataoutputstream _outputstream;  receiver _receiver; thread _thread;  ontcpdatareceivedlistener _ontcpdatareceived;  public tcpconnection() {                       _state = state.closed; }  // listen informed of data has been received tcp / ip socket. public void setontcpdatareceivedlistener(ontcpdatareceivedlistener listener)    {     _ontcpdatareceived = listener; }  // used inform listener data has been received tcp / ip socket. public interface ontcpdatareceivedlistener {     public void ontcpdatareceived(byte[] buffer, int length); }  // try connecting given tcp / ip connection. // notes: // blocks until connection created. // if connected public synchronized void connect(string ipaddress, int port)  throws ioexception {     if (_state != state.closed)         return;      try     {         _state = state.open;          _socket = new socket(ipaddress, port);         _inputstream = new datainputstream(_socket.getinputstream());         _outputstream = new dataoutputstream(_socket.getoutputstream());                 }     catch(ioexception ex)     {                     //todo: better error handling         ex.printstacktrace();          if (_socket != null) {             _socket.close();             _socket = null;                      }          if (_inputstream != null) {             _inputstream.close();             _inputstream = null;         }          if (_outputstream != null) {             _outputstream.close();             _outputstream = null;         }          throw ex;     }      _receiver = new receiver();      _thread = new thread(_receiver);     _thread.setname("tcpconnection.receiver");     _thread.start(); }  public void write(byte[] buffer) {     if (_state != state.open)         return;      try     {         _outputstream.write(buffer);     }     catch(ioexception ex)     {                     //todo: better error handling         ex.printstacktrace();                 }  }  public synchronized void close() {     _state = state.closing;      if (_socket != null && !_socket.isclosed())     {         try         {             _socket.close();         }         catch(ioexception ex)         {             //todo: better error handling             ex.printstacktrace();         }     }          }  private class receiver implements runnable {                                       @override     public void run()      {                                 try          {             byte[] buffer = new byte[512];             int read = 0;              while(_state == state.open)             {                                     read = _inputstream.read(buffer);                  if (read > 0)                 {                     if (_ontcpdatareceived != null)                     {                         _ontcpdatareceived.ontcpdatareceived(buffer, read);                     }                 }             }         }         catch (socketexception ex)         {             if (    !(_state != state.open                      && ex.getmessage() != null                      && ex.getmessage().equalsignorecase("socket closed")))             {                 ex.printstacktrace();             }         }         catch (ioexception ex)          {             //todo: need error handling             ex.printstacktrace();         }                              {             if (_socket != null && !_socket.isclosed())             {                 try                 {                     _socket.close();                 }                 catch (ioexception ex)                  {                     //todo: need error handling                     ex.printstacktrace();                 }                                 }         }          _state = state.closed;      } }    

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you have couple of choices:

1. update actual android class uses tcpconnection wrap calls tcpconnection in separate thread: create executor , use that.
2. add executor instance tcpconnection handles transmission , reception. expect issue connect function: maybe try wrapping code in separate runnable , launching on thread?