Thanks for your explanation Bryan, it seems that I could only get the DBCP controller service's driver name after something like getDrivername() is added into the current DBCPService interface.
Regards, Ben 2017-08-10 22:01 GMT+08:00 Bryan Bende <bbe...@gmail.com>: > The way controller services are setup you have the following... > > - DBCPService interface (provides getConnection()) extends > ControllerService interface (empty interface to indicate it is a CS) > - DBCPConnectionPool extends AbstractControllerService implements > DBCPService > - Processor XYZ depends on DBCPService interface > > The DBCPService interface is the common point between the processor > and the implementations. The processor XYZ classpath only knows about > the DBCPService interface, it doesn't know anything about the classes > that implement it... there could actually be several implementations > in different NARs, but it is up to the framework to provide access to > these. > > Since the processor only depends on the interface, which in this case > only exposes getConnection(), you can't really assume the service has > certain properties because DBCPConnectionPool.DB_DRIVERNAME is > specific to the DBCPConnectionPool implementation... another > implementation may not have that property, or may call it something > different. The interface would have to provide getDriverName() so that > each implementation could provide that. > > -Bryan > > > On Thu, Aug 10, 2017 at 4:33 AM, 尹文才 <batman...@gmail.com> wrote: > > Thanks Andy, I've tried your approach, in my case the controller service > is > > a DBCPConnectionPool and when I tried to get driver class name property > > through context.getProperty(DBCPConnectionPool.DB_ > DRIVERNAME).getValue(), > > but I the value is null. The AbstractControllerService class does have a > > method getConfigurationContext() to get configuration context, but the > > method is protected. So I still didn't find a feasible way to get the > > controller service's properties. > > > > Regards, > > Ben > > > > 2017-08-10 12:18 GMT+08:00 Andy LoPresto <alopre...@apache.org>: > > > >> You can get the current property values of a controller service from the > >> processor by using the ProcessContext object. For example, in GetHTTP > , > >> in the @OnScheduled method, you could do: > >> > >> context.getControllerServiceLookup().getControllerService("my- > >> controller-service-id”); > >> > >> context.getProperty("controller-service-property-name"); > >> context.getProperty(SomeControllerService. > CONSTANT_PROPERTY_DESCRIPTOR); > >> > >> I forget if context.getProperty() will give the controller service > >> properties as well as the processor properties. If it doesn’t, you can > cast > >> the retrieved ControllerService into AbstractControllerService or the > >> concrete class and access available properties directly from the > >> encapsulated ConfigurationContext. > >> > >>  https://github.com/apache/nifi/blob/master/nifi-nar- > >> bundles/nifi-standard-bundle/nifi-standard-processors/src/ > >> main/java/org/apache/nifi/processors/standard/GetHTTP.java#L295 > >> > >> Andy LoPresto > >> alopre...@apache.org > >> *alopresto.apa...@gmail.com <alopresto.apa...@gmail.com>* > >> PGP Fingerprint: 70EC B3E5 98A6 5A3F D3C4 BACE 3C6E F65B 2F7D EF69 > >> > >> On Aug 9, 2017, at 6:57 PM, 尹文才 <batman...@gmail.com> wrote: > >> > >> Thanks Koji, I checked the link you provided and I think getting a > >> DataSource is no different than getting the DBCP service(they could just > >> get the connection). Actually I was trying to get the configured driver > >> class to check the database type. > >> > >> Regards, > >> Ben > >> > >> 2017-08-10 9:29 GMT+08:00 Koji Kawamura <ijokaruma...@gmail.com>: > >> > >> Hi Ben, > >> > >> I'm not aware of ways to obtain configurations of a controller from a > >> processor. Those should be encapsulated inside a controller service. > >> If you'd like to create DataSource instance instead of just obtaining > >> a connection, this discussion might be helpful: > >> https://github.com/apache/nifi/pull/1417 > >> > >> Although I would not recommend, if you really need to obtain all > >> configurations, you can do so by calling NiFi REST API from your > >> processor. > >> > >> Thanks, > >> Koji > >> > >> On Thu, Aug 10, 2017 at 10:09 AM, 尹文才 <batman...@gmail.com> wrote: > >> > >> Hi guys, I have a customized processor with a DBCP controller service as > >> > >> a > >> > >> property. I could get the DBCP controller service in my code, but does > >> anyone know how to obtain all the configurations of the DBCP controller > >> service in java code(e.g. Database Connection URL, Database Driver > >> Location, etc) Thanks. > >> > >> Regards, > >> Ben > >> > >> > >> > >> >