/** * openConnections: open the connection to the master. has retry mechanism * * @return: true if the connection is built, false if failed */ public boolean openConnections() { _log("Try to connect to Master..."); int i = 0; while (true) { boolean isConnected = connect(); if (!isConnected) { i++; if (i == DropboxConstants.MAX_TRY) { break; } _log("Cannot connect to Master, retry " + i); try { Thread.sleep(DropboxConstants.TRY_CONNECT_MILLIS); } catch (InterruptedException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } _log("Retry connection is interrupted"); break; } } else { _log("Success!"); return true; } } _log("Failed"); return false; }
/** listen: start to listen if there is any clients connected */ public void listen() { // Firstly spawn a new thread and then the main thread // also start listening _userNet = new DropboxFileServerUserNet(_server, _userOut, _userIn, _userSock); _userNet.start(); /* Use main thread, cannot be stopped */ while (_sock != null && !_sock.isClosed()) { try { String line = NetComm.receive(_in); _dlog(line); parse(line); } catch (Exception e) { if (!_server.noException()) { _elog(e.toString()); } break; // Break the loop } } /* Clear */ // Close main thread clear(); // Cancel the listening thread and retry _server.cancelListeningThread(); /* Also cancel all of the syncers */ _server.cancelSyncers(); // Retry after try { _log( "The connection to master is broken," + " reset everything and retry connection after " + DropboxConstants.TRY_CONNECT_MILLIS + " milliseconds"); Thread.sleep(DropboxConstants.TRY_CONNECT_MILLIS); } catch (InterruptedException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } } _server.run(); clear(); _log(_threadName + " is stopped"); }
/** * parse: parse the string and send response * * @param str: the given string */ protected void parse(String str) { StringTokenizer st = new StringTokenizer(str); String tkn = st.nextToken(); try { if (tkn.equals(ProtocolConstants.PACK_STR_HEARTBEAT_HEAD)) { _dlog("I got heartbeat"); // Send back confirmation // TODO: add more story here NetComm.send(ProtocolConstants.PACK_STR_HEARTBEAT_HEAD, _out); } else if (tkn.equals(ProtocolConstants.PACK_STR_REQUEST_FS_HEAD)) { // TODO: add more story here } else { _elog("Invalid header, skip."); } } catch (Exception e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } } }
/** * close: close the socket and stream * * @return: true for success, false for error */ protected boolean close() { _dlog("Do main thread closing..."); if (_sock != null && !_sock.isClosed()) { _dlog("Closing the receiving thread"); try { _sock.close(); _in.close(); _out.close(); _sock = null; _in = null; _out = null; _dlog("Success!"); } catch (IOException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } return false; } } _sock = null; _in = null; _out = null; _dlog("Cancel the user input thread"); if (_userNet != null) { _userNet.stop(); _userNet.join(); // guaranteed to be closed _userNet = null; } if (_userSock != null && !_userSock.isClosed()) { _dlog("Closing the user input thread"); // Stop the user thread try { _userSock.close(); _userIn.close(); _userOut.close(); _userSock = null; _userIn = null; _userOut = null; _dlog("Success!"); } catch (IOException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } return false; } } _userSock = null; _userIn = null; _userOut = null; /* Cancel all client nodes */ _dlog("Finished"); return true; /* CAUTION: _server is never cleared */ }
private void _dlog(String str) { if (_server.debugMode()) System.out.println("[DropboxFileServerMasterNet (DEBUG)]:" + str); }
/** * connect: connect to the master * * @return: true for success and false for failure */ protected boolean connect() { boolean connected = true; try { _sock = new Socket(_serverIP, _serverPort); _out = new PrintWriter(_sock.getOutputStream(), true); _in = new BufferedReader(new InputStreamReader(_sock.getInputStream())); String reply = sendAll(); if (!reply.equals(ProtocolConstants.PACK_STR_CONFIRM_HEAD)) { /* Tokenize */ StringTokenizer st = new StringTokenizer(reply); if (st.nextToken().equals(ProtocolConstants.PACK_STR_ERRMES_HEAD)) { _elog(st.nextToken()); return false; } } _userSock = new Socket(_serverIP, _serverPort); _userOut = new PrintWriter(_userSock.getOutputStream(), true); _userIn = new BufferedReader(new InputStreamReader(_userSock.getInputStream())); String replyUser = sendUserID(); if (!replyUser.equals(ProtocolConstants.PACK_STR_CONFIRM_HEAD)) { throw new Exception("Not confirmed"); } } catch (UnknownHostException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } connected = false; } catch (IOException e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } connected = false; } catch (Exception e) { if (!_server.noException()) { _elog(e.toString()); } if (_server.debugMode()) { e.printStackTrace(); } connected = false; } if (!connected) { return connected; } if (!connected) { /* Remove the pair of socket */ _sock = null; _in = null; _out = null; _userSock = null; _userOut = null; _userIn = null; } return connected; }