Yes, I agree. One of the few use cases of Java 8s default methods in interfaces...
Julian -------- Ursprüngliche Nachricht -------- Betreff: Re: Reconnect of driver 2 Von: Christofer Dutz An: [email protected] Cc: Hi All, I would agree that a void type and exceptions would allow a more fine-grained reporting of what's going on. Sort of: - "Yeah ... I am a S7 400, but I don't support the S7-TIA protocol" - "No connection under this number" (no connection possible) - "You're not allowed to connect" - "Invalid credentials" - ... Maybe we should do that ASAP, adding it to the API, but have it report "Not Implemented" for now and to create JIRA tickets for the individual drivers ping implementations. Chris Am 26.03.19, 14:44 schrieb "Julian Feinauer" <[email protected]>: Hi Gunther, thats really great to hear : ) When I remember correctly the idea was... 1. Extend the PlcConnection interface with a "ping()" method (Boolean? Throw Exception if not possible?) 2. Implement the Ping functionality for each plc with a sensible "operation" (not sure what this could be for S7... read the SLZ or something?) 3. Use this feature as "keep alive" e.g. for the PooledDriverManager does that make sense? Julian Am 26.03.19, 13:55 schrieb "Gunther Gruber" <[email protected]>: Sure I like to contribute. I guess by that you mean checking out the code and create a pull request with something working. I like your idear with the ping check. I will focus on implementing a function for the ping check, which can be reused later. Gunther > Hi Gunther, > > good catch : ) > In fact, the isConnected() implementation is currently not soo god. > In fact it checks if the underlying communication channel from netty is connected (which does not know that it is disconnected yet, in your case). > We already had discussions to introduce a real "request" based implementation like "ping()" which sends a request. > > Furthermore, for your use case there is the PooledDriverManager which does implicitly what you do... throws away a not working connection and issues a new one, if needed, but that’s a separate topic. > > I think we should spend some effort into this "ping" functionality. > Perhaps you can even assist with the implementation Gunther, what do you think? > > Julian > > Am 26.03.19, 11:19 schrieb "Gunther Gruber" <[email protected]>: > > Put it another way, isConnected does not work as i expect it > > plcConnection.isConnected() returns true even when i disconnect the vpn (maybe of some tcp/ip keepalive?) > > this is the snippet of code which i expect to work (instead of the thread which reconnects ever 10 minutes) > while (doCollect) { > > try { > if (plcConnection == null || plcConnection.isConnected() == false) { > plcConnection = initPLC(config.get(CONNECTION_KEY)); > } > } catch (PlcConnectionException e) { > logger.log(Level.WARNING, "error connecting with driver", e); > plcConnection = null; > incrementalSleep(); > break; > } > > // Create a new read request: > // - Give the single item requested the alias name "value" > PlcReadRequest.Builder builder = plcConnection.readRequestBuilder(); > > Gunther Gruber > > >
