sruehl commented on a change in pull request #57: Feature/plc4 x 108 ping method URL: https://github.com/apache/incubator-plc4x/pull/57#discussion_r270368233
########## File path: plc4j/protocols/driver-bases/base/src/main/java/org/apache/plc4x/java/base/connection/AbstractPlcConnection.java ########## @@ -57,6 +67,42 @@ public boolean canSubscribe() { return false; } + /** + * The default implementation uses the {@link #ping(int)} method. + * Drivers that want to implement a more specific version have to overide it. + */ + @Override + public boolean isConnected() { + return ping(PING_TIMEOUT_MS); + } + + /** + * Method that sends a test-request or ping to the PLC to check if the PLC is still there. + * In most cases this method should only be used from the {@link #isConnected()} method. + * This method can only be used if ghe {@link #getInetSocketAddress()} returns a Socket Adress. + * Otherwise it throws a {@link NotImplementedException} to inform the user about that. + */ + protected boolean ping(int timeout) { + Optional<InetSocketAddress> address = getInetSocketAddress(); + if (!address.isPresent()) { + throw new NotImplementedException("Tries to check the connection with ping, " + + "but no Socket Address is given!"); + } + try (Socket s = new Socket()) { + s.connect(address.get(), timeout); Review comment: I'm not sure if we should call .disconnect() here as well. Does socket.close() does this. If thats isn't the case we should call it so the socket doesn't stay open on the other side ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services