Compiling custom processor
Ok, I am far from a maven expert, and am struggling on this problem. I created a new project using the maven generate process, and compiled that sample processor and everything was fine, and I could see it in my local NiFi instance. I then copied over the Wait processor on top of the MyProcessor.java class, changed the package name, and the class name, and attempted to compile. Got errors due to dependency issues. This is where I get confused. In the processor directory, I modify the pom.xml with a dependency line for nifi-api, nifi-utils, nifi-distribute-cache-client-service-api and nifi-standard-processors. This seemed to make things work, and I get a 33 meg NAR file, which contains lots of JARs. I load that up, and I get a problem with CalculateStats, or similar, because of RecordReaderFactory. I go back in and include nifi-record-serialization-services, and it compiles, and the JAR is included in the NAR file now, and I still get class not found. I've also tried to change the dependencies to a status of provided, and therefore get a minimal 25k or so NAR file with no JARs included. I get the same issue with the class not found. I had also attempted to copy Wait.java to AnotherWait.java within the actually NiFi source code, and it compiles, and shows up in the JARs and NARs as I'd expect, but I cannot get to it within my NiFi instance. Can someone let me know what I'm doing wrong. Thanks, John McGinn
Re: Compiling custom processor
In general, if your processor uses a controller service then the processors pom file needs a provided dependency on the API of the CS, and your NAR pom needs a NAR dependency on the NAR where the CS API is. Example is shown here in the section linking processors and controller services - https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions Also, you do not want to include NiFI's standard processors in your own NAR, this will result in two copies of every standard processor. You will want to copy whatever code you need into your own NAR. In you last statement, if you made a new processor in nifi-standard-processors and it didn't show up, it is most likely because you didn't update META-INF/services file to include the new processor. On Tue, Oct 16, 2018 at 9:36 AM John McGinn wrote: > > Ok, I am far from a maven expert, and am struggling on this problem. > > I created a new project using the maven generate process, and compiled that > sample processor and everything was fine, and I could see it in my local NiFi > instance. I then copied over the Wait processor on top of the > MyProcessor.java class, changed the package name, and the class name, and > attempted to compile. Got errors due to dependency issues. This is where I > get confused. > > In the processor directory, I modify the pom.xml with a dependency line for > nifi-api, nifi-utils, nifi-distribute-cache-client-service-api and > nifi-standard-processors. This seemed to make things work, and I get a 33 meg > NAR file, which contains lots of JARs. I load that up, and I get a problem > with CalculateStats, or similar, because of RecordReaderFactory. I go back in > and include nifi-record-serialization-services, and it compiles, and the JAR > is included in the NAR file now, and I still get class not found. > > I've also tried to change the dependencies to a status of provided, and > therefore get a minimal 25k or so NAR file with no JARs included. I get the > same issue with the class not found. > > I had also attempted to copy Wait.java to AnotherWait.java within the > actually NiFi source code, and it compiles, and shows up in the JARs and NARs > as I'd expect, but I cannot get to it within my NiFi instance. > > Can someone let me know what I'm doing wrong. > > Thanks, > John McGinn
Re: Compiling custom processor
If you want to look at a large Maven project that builds several custom NARs from one unified build system, take a look at my data generation bundle here: https://github.com/MikeThomsen/nifi-datageneration-bundle On Tue, Oct 16, 2018 at 9:53 AM Bryan Bende wrote: > In general, if your processor uses a controller service then the > processors pom file needs a provided dependency on the API of the CS, > and your NAR pom needs a NAR dependency on the NAR where the CS API > is. > > Example is shown here in the section linking processors and controller > services - > https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions > > Also, you do not want to include NiFI's standard processors in your > own NAR, this will result in two copies of every standard processor. > You will want to copy whatever code you need into your own NAR. > > In you last statement, if you made a new processor in > nifi-standard-processors and it didn't show up, it is most likely > because you didn't update META-INF/services file to include the new > processor. > On Tue, Oct 16, 2018 at 9:36 AM John McGinn > wrote: > > > > Ok, I am far from a maven expert, and am struggling on this problem. > > > > I created a new project using the maven generate process, and compiled > that sample processor and everything was fine, and I could see it in my > local NiFi instance. I then copied over the Wait processor on top of the > MyProcessor.java class, changed the package name, and the class name, and > attempted to compile. Got errors due to dependency issues. This is where I > get confused. > > > > In the processor directory, I modify the pom.xml with a dependency line > for nifi-api, nifi-utils, nifi-distribute-cache-client-service-api and > nifi-standard-processors. This seemed to make things work, and I get a 33 > meg NAR file, which contains lots of JARs. I load that up, and I get a > problem with CalculateStats, or similar, because of RecordReaderFactory. I > go back in and include nifi-record-serialization-services, and it compiles, > and the JAR is included in the NAR file now, and I still get class not > found. > > > > I've also tried to change the dependencies to a status of provided, and > therefore get a minimal 25k or so NAR file with no JARs included. I get the > same issue with the class not found. > > > > I had also attempted to copy Wait.java to AnotherWait.java within the > actually NiFi source code, and it compiles, and shows up in the JARs and > NARs as I'd expect, but I cannot get to it within my NiFi instance. > > > > Can someone let me know what I'm doing wrong. > > > > Thanks, > > John McGinn >
Re: Compiling custom processor
Thanks Bryan, I restarted with a fresh maven generate, and only added the API to the processor pom, and then the API-NAR to the NAR pom. I then figured out a subsequent dependency (lang3), and got that in, and now my processor shows up in local NiFi instance. Regarding the copying of the standard processor, when I copied Wait over, I renamed it from Wait to MyProcessorWait to be unique, and not copied. I'm just attempting changes to Wait without modifying the actual one. Also, thanks on the META-INF/services file information. Now I can debug and test. Sincerely, John McGinn On Tue, 10/16/18, Bryan Bende wrote: Subject: Re: Compiling custom processor To: dev@nifi.apache.org Date: Tuesday, October 16, 2018, 9:52 AM In general, if your processor uses a controller service then the processors pom file needs a provided dependency on the API of the CS, and your NAR pom needs a NAR dependency on the NAR where the CS API is. Example is shown here in the section linking processors and controller services - https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions Also, you do not want to include NiFI's standard processors in your own NAR, this will result in two copies of every standard processor. You will want to copy whatever code you need into your own NAR. In you last statement, if you made a new processor in nifi-standard-processors and it didn't show up, it is most likely because you didn't update META-INF/services file to include the new processor. On Tue, Oct 16, 2018 at 9:36 AM John McGinn wrote: > > Ok, I am far from a maven expert, and am struggling on this problem. > > I created a new project using the maven generate process, and compiled that sample processor and everything was fine, and I could see it in my local NiFi instance. I then copied over the Wait processor on top of the MyProcessor.java class, changed the package name, and the class name, and attempted to compile. Got errors due to dependency issues. This is where I get confused. > > In the processor directory, I modify the pom.xml with a dependency line for nifi-api, nifi-utils, nifi-distribute-cache-client-service-api and nifi-standard-processors. This seemed to make things work, and I get a 33 meg NAR file, which contains lots of JARs. I load that up, and I get a problem with CalculateStats, or similar, because of RecordReaderFactory. I go back in and include nifi-record-serialization-services, and it compiles, and the JAR is included in the NAR file now, and I still get class not found. > > I've also tried to change the dependencies to a status of provided, and therefore get a minimal 25k or so NAR file with no JARs included. I get the same issue with the class not found. > > I had also attempted to copy Wait.java to AnotherWait.java within the actually NiFi source code, and it compiles, and shows up in the JARs and NARs as I'd expect, but I cannot get to it within my NiFi instance. > > Can someone let me know what I'm doing wrong. > > Thanks, > John McGinn
Re: Compiling custom processor
And I'm back. So, I had my processor running, no errors, so things were good. I then add 2 if statements with logger messages, run the same mvn command, copied the new NAR on top of the old one, same versionId and all, and now I get a class not found error, that didn't occur before I stopped, redeployed and started. And I can't delete the event in the queue even though source and destination are stopped. Is there problems when redeploying a custom processor NAR on top of itself? Even if the NiFi instance is stopped? Serialization issues? Frustratedly yours, John McGinn On Tue, 10/16/18, John McGinn wrote: Subject: Re: Compiling custom processor To: dev@nifi.apache.org Date: Tuesday, October 16, 2018, 1:21 PM Thanks Bryan, I restarted with a fresh maven generate, and only added the API to the processor pom, and then the API-NAR to the NAR pom. I then figured out a subsequent dependency (lang3), and got that in, and now my processor shows up in local NiFi instance. Regarding the copying of the standard processor, when I copied Wait over, I renamed it from Wait to MyProcessorWait to be unique, and not copied. I'm just attempting changes to Wait without modifying the actual one. Also, thanks on the META-INF/services file information. Now I can debug and test. Sincerely, John McGinn On Tue, 10/16/18, Bryan Bende wrote: Subject: Re: Compiling custom processor To: dev@nifi.apache.org Date: Tuesday, October 16, 2018, 9:52 AM In general, if your processor uses a controller service then the processors pom file needs a provided dependency on the API of the CS, and your NAR pom needs a NAR dependency on the NAR where the CS API is. Example is shown here in the section linking processors and controller services - https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions Also, you do not want to include NiFI's standard processors in your own NAR, this will result in two copies of every standard processor. You will want to copy whatever code you need into your own NAR. In you last statement, if you made a new processor in nifi-standard-processors and it didn't show up, it is most likely because you didn't update META-INF/services file to include the new processor. On Tue, Oct 16, 2018 at 9:36 AM John McGinn wrote: > > Ok, I am far from a maven expert, and am struggling on this problem. > > I created a new project using the maven generate process, and compiled that sample processor and everything was fine, and I could see it in my local NiFi instance. I then copied over the Wait processor on top of the MyProcessor.java class, changed the package name, and the class name, and attempted to compile. Got errors due to dependency issues. This is where I get confused. > > In the processor directory, I modify the pom.xml with a dependency line for nifi-api, nifi-utils, nifi-distribute-cache-client-service-api and nifi-standard-processors. This seemed to make things work, and I get a 33 meg NAR file, which contains lots of JARs. I load that up, and I get a problem with CalculateStats, or similar, because of RecordReaderFactory. I go back in and include nifi-record-serialization-services, and it compiles, and the JAR is included in the NAR file now, and I still get class not found. > > I've also tried to change the dependencies to a status of provided, and therefore get a minimal 25k or so NAR file with no JARs included. I get the same issue with the class not found. > > I had also attempted to copy Wait.java to AnotherWait.java within the actually NiFi source code, and it compiles, and shows up in the JARs and NARs as I'd expect, but I cannot get to it within my NiFi instance. > > Can someone let me know what I'm doing wrong. > > Thanks, > John McGinn
Re: Compiling custom processor
There shouldn't be any issue doing that, generally you just copy the new NAR into the lib directory and restart. What were the specifics of the class not found error? On Tue, Oct 16, 2018 at 3:24 PM John McGinn wrote: > > And I'm back. > > So, I had my processor running, no errors, so things were good. > > I then add 2 if statements with logger messages, run the same mvn command, > copied the new NAR on top of the old one, same versionId and all, and now I > get a class not found error, that didn't occur before I stopped, redeployed > and started. And I can't delete the event in the queue even though source and > destination are stopped. > > Is there problems when redeploying a custom processor NAR on top of itself? > Even if the NiFi instance is stopped? Serialization issues? > > Frustratedly yours, > John McGinn > > ---- > On Tue, 10/16/18, John McGinn wrote: > > Subject: Re: Compiling custom processor > To: dev@nifi.apache.org > Date: Tuesday, October 16, 2018, 1:21 PM > > Thanks Bryan, > > I restarted with a fresh maven > generate, and only added the API to the processor pom, and > then the API-NAR to the NAR pom. I then figured out a > subsequent dependency (lang3), and got that in, and now my > processor shows up in local NiFi instance. > > Regarding the copying of the standard > processor, when I copied Wait over, I renamed it from Wait > to MyProcessorWait to be unique, and not copied. I'm just > attempting changes to Wait without modifying the actual one. > Also, thanks on the META-INF/services file information. > > Now I can debug and test. > > Sincerely, > John McGinn > > > On Tue, 10/16/18, Bryan Bende > wrote: > > Subject: Re: Compiling custom > processor > To: dev@nifi.apache.org > Date: Tuesday, October 16, 2018, 9:52 > AM > > In general, if your processor > uses a controller service then the > processors pom file needs a provided > dependency > on the API of the CS, > and your NAR pom needs > a NAR dependency on the NAR where the > CS API > is. > > Example is > shown here in the section linking > processors and > controller > services - > https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions > > Also, you do not want to > include NiFI's standard processors in > your > own NAR, this will result in two > copies of > every standard processor. > You will want to > copy whatever code you need into your > own NAR. > > In you last statement, if you > made a new processor in > nifi-standard-processors and it didn't > show > up, it is most likely > because you didn't > update META-INF/services file to > include the new > processor. > On Tue, Oct 16, 2018 at > 9:36 AM John McGinn > > wrote: > > > > Ok, I am > far from a maven expert, and am > struggling on this > problem. > > > > I created > a new project using the maven generate > process, and compiled > that sample processor and everything > was fine, and I could > see it in my local NiFi instance. I > then copied over the > Wait processor on top of the > MyProcessor.java class, changed > the package name, and the class name, > and attempted to > compile. Got errors due to dependency > issues. This is where > I get confused. > > > > In > the processor directory, I modify the > pom.xml with a > dependency line for nifi-api, > nifi-utils, > > nifi-distribute-cache-client-service-api and > nifi-standard-processors. This seemed > to make things work, > and I get a 33 meg NAR file, which > contains lots of JARs. I > load that up, and I get a problem with > CalculateStats, or > similar, because of > RecordReaderFactory. I go back in and > include > nifi-record-serialization-services, and it compiles, > and the JAR is included in the NAR > file now, and I still get > class not found. > > > > > I've also tried to change the > dependencies to a status > of provided, and therefore get a > minimal 25k or so NAR file > with no JARs included. I get the same > issue with the class > not found. > > > > I had > also attempted to copy Wait.java to > AnotherWait.java within > the actually NiFi source code, and it > compiles, and shows up > in the JARs and NARs as I'd expect, > but I cannot get to > it within my NiFi instance. > > > > Can someone let me know what I'm > doing > wrong. > > > > Thanks, > > John McGinn >
Re: Compiling custom processor
I have a directory /home/user/nifi-nars, which is listed in the nifi.properties file located under the nifi-assembly directory from the nifi-master code. That's where I redropped my NAR file at. The error was "due to uncaught Exception: java.lang.NoClassDefFoundError: org/apache/commons/lang3/StringUtils". I added a provided dependency of version 3.4 for commons-lang3 in my processors pom.xml. That worked initially, but with the redropping of the NAR file, the error occurs. The stacktrace points to the session.get() lambda function trying to use StringUtils.isBlank(). (Again, this is a copy and renamed class of the Wait Processor. Trying to turn it into a Yield, as it were, hold unless it's free to move forward.) On Tue, 10/16/18, Bryan Bende wrote: Subject: Re: Compiling custom processor To: dev@nifi.apache.org Date: Tuesday, October 16, 2018, 3:34 PM There shouldn't be any issue doing that, generally you just copy the new NAR into the lib directory and restart. What were the specifics of the class not found error? On Tue, Oct 16, 2018 at 3:24 PM John McGinn wrote: > > And I'm back. > > So, I had my processor running, no errors, so things were good. > > I then add 2 if statements with logger messages, run the same mvn command, copied the new NAR on top of the old one, same versionId and all, and now I get a class not found error, that didn't occur before I stopped, redeployed and started. And I can't delete the event in the queue even though source and destination are stopped. > > Is there problems when redeploying a custom processor NAR on top of itself? Even if the NiFi instance is stopped? Serialization issues? > > Frustratedly yours, > John McGinn > > ---- > On Tue, 10/16/18, John McGinn wrote: > > Subject: Re: Compiling custom processor > To: dev@nifi.apache.org > Date: Tuesday, October 16, 2018, 1:21 PM > > Thanks Bryan, > > I restarted with a fresh maven > generate, and only added the API to the processor pom, and > then the API-NAR to the NAR pom. I then figured out a > subsequent dependency (lang3), and got that in, and now my > processor shows up in local NiFi instance. > > Regarding the copying of the standard > processor, when I copied Wait over, I renamed it from Wait > to MyProcessorWait to be unique, and not copied. I'm just > attempting changes to Wait without modifying the actual one. > Also, thanks on the META-INF/services file information. > > Now I can debug and test. > > Sincerely, > John McGinn > > > On Tue, 10/16/18, Bryan Bende > wrote: > > Subject: Re: Compiling custom > processor > To: dev@nifi.apache.org > Date: Tuesday, October 16, 2018, 9:52 > AM > > In general, if your processor > uses a controller service then the > processors pom file needs a provided > dependency > on the API of the CS, > and your NAR pom needs > a NAR dependency on the NAR where the > CS API > is. > > Example is > shown here in the section linking > processors and > controller > services - >https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions > > Also, you do not want to > include NiFI's standard processors in > your > own NAR, this will result in two > copies of > every standard processor. > You will want to > copy whatever code you need into your > own NAR. > > In you last statement, if you > made a new processor in > nifi-standard-processors and it didn't > show > up, it is most likely > because you didn't > update META-INF/services file to > include the new > processor. > On Tue, Oct 16, 2018 at > 9:36 AM John McGinn > > wrote: > > > > Ok, I am > far from a maven expert, and am > struggling on this > problem. > > > > I created > a new project using the maven generate > process, and compiled > that sample processor and everything > was fine, and I could > see it in my local NiFi instance. I > then copied over the > Wait processor on top of the > MyProcessor.java class, changed > the package name, and the class name, > and attempted to > compile. Got errors due to dependency > issues. This is where > I get confused. > > > > In > the processor directory, I modify the > pom.xml with a > dependency line for nifi
Re: Compiling custom processor
Any reason why the commons-lang3 dependency is provided and not normal compile scope? Generally the only cases where a dependency should be provided are when a parent NAR provides it (the API scenario earlier), or when it is a jar directly in lib which means it is on the classpath of everything (like nifi-api or slf4j). On Tue, Oct 16, 2018 at 3:47 PM John McGinn wrote: > > I have a directory /home/user/nifi-nars, which is listed in the > nifi.properties file located under the nifi-assembly directory from the > nifi-master code. That's where I redropped my NAR file at. > > The error was "due to uncaught Exception: java.lang.NoClassDefFoundError: > org/apache/commons/lang3/StringUtils". I added a provided dependency of > version 3.4 for commons-lang3 in my processors pom.xml. That worked > initially, but with the redropping of the NAR file, the error occurs. The > stacktrace points to the session.get() lambda function trying to use > StringUtils.isBlank(). (Again, this is a copy and renamed class of the Wait > Processor. Trying to turn it into a Yield, as it were, hold unless it's free > to move forward.) > ---- > On Tue, 10/16/18, Bryan Bende wrote: > > Subject: Re: Compiling custom processor > To: dev@nifi.apache.org > Date: Tuesday, October 16, 2018, 3:34 PM > > There shouldn't be any issue > doing that, generally you just copy the > new > NAR into the lib directory and restart. > > What were the specifics of the class not found > error? > > On Tue, Oct 16, 2018 at > 3:24 PM John McGinn > wrote: > > > > And I'm > back. > > > > So, I had my > processor running, no errors, so things were good. > > > > I then add 2 if > statements with logger messages, run the same mvn command, > copied the new NAR on top of the old one, same versionId and > all, and now I get a class not found error, that didn't > occur before I stopped, redeployed and started. And I > can't delete the event in the queue even though source > and destination are stopped. > > > > Is there problems when redeploying a > custom processor NAR on top of itself? Even if the NiFi > instance is stopped? Serialization issues? > > > > Frustratedly > yours, > > John McGinn > > > > > > > On Tue, 10/16/18, John McGinn > wrote: > > > > Subject: > Re: Compiling custom processor > > To: dev@nifi.apache.org > > Date: Tuesday, October 16, 2018, 1:21 > PM > > > > Thanks > Bryan, > > > > I > restarted with a fresh maven > > > generate, and only added the API to the processor pom, > and > > then the API-NAR to the NAR pom. > I then figured out a > > subsequent > dependency (lang3), and got that in, and now my > > processor shows up in local NiFi > instance. > > > > > Regarding the copying of the standard > > > processor, when I copied Wait over, I renamed it from > Wait > > to MyProcessorWait to be unique, > and not copied. I'm just > > > attempting changes to Wait without modifying the actual > one. > > Also, thanks on the > META-INF/services file information. > > > > Now I can debug and test. > > > > Sincerely, > > John McGinn > > > > > > > On Tue, 10/16/18, Bryan Bende > > wrote: > > > > Subject: Re: Compiling custom > > processor > > To: dev@nifi.apache.org > > Date: Tuesday, October 16, 2018, > 9:52 > > AM > > > > In general, if your processor > > uses a controller service then the > > processors pom file needs a provided > > dependency > > on > the API of the CS, > > and your NAR pom > needs > > a NAR dependency on the NAR > where the > > CS API > > is. > > > > Example is > > > shown here in the section linking > > > processors and > > controller > > services - > https://cwiki.apache.org/confluence/display/NIFI/Maven+Projects+for+Extensions > > > > Also, you do not > want to > > include NiFI's standard > processors in > > your > > own NAR, this will result in two > > copies of > > every > standard processor. > > You will want > to > > copy whatever code you need into > your > > own NAR. > > > > In you last statement,
Re: Compiling custom processor
Thanks Bryan. That was a mistake on my part. I thought that I could use part of the NiFi standard processors in my custom processor. I suppose this also means it's not possible to extend a standard processor class, say Wait, and override a method, for instance, onTrigger(), to do different work. Instead, as you state, I should copy the portions I would need to my custom processor. Is that accurate? In the end, as I was looking through how to modify Wait, I think it is bigger than the need that I have, so I restarted with a new generated processor project, and just added the cache service, and appropriate relationships, and simple logic to control flow through my processor. I'll work on getting a github account and uploading my simple processor. Thanks for the assistance John McGinn On Tue, 10/16/18, Bryan Bende wrote: Subject: Re: Compiling custom processor To: figgie...@sbcglobal.net Date: Tuesday, October 16, 2018, 4:45 PM You shouldn't really try to depend on code inside other NARs like standard processors, you'll want to copy WaitNotifyProtocol into your own NAR. On Tue, Oct 16, 2018 at 4:40 PM John McGinn wrote: > > The commons-lang3-3.7.jar file is located in the lib/bootstrap directory, therefore, I figured it could be considered provided. I've since change it to normal scope, and it is included in my NAR and that error goes away. So, this > then leans on the next error I get, which is no class found for the WaitNotifyProtocol in nifi.processors.standard. Is there an easy way to figure out what NiFi class/object I'm using, and what NAR should be listed as provided? I tried to add nifi-standard-processors-nar, but that doesn't exist for maven, nor does it exist in the lib directory. I looked inside the nifi-standard-nar NAR file, and the nifi-standard-processors is there, and inside that is WaitNotifyProtocol, but yet, my maven won't build if I have nifi-standard-nar listed, either with type of NAR, or scope of provided. > > On Tue, 10/16/18, Bryan Bende wrote: > > Subject: Re: Compiling custom processor > To: dev@nifi.apache.org, figgie...@sbcglobal.net > Date: Tuesday, October 16, 2018, 4:01 PM > > Any reason why the commons-lang3 > dependency is provided and not normal > compile scope? > > Generally the only cases where a dependency > should be provided are > when a parent NAR > provides it (the API scenario earlier), or when it > is a jar directly in lib which means it is on > the classpath of > everything (like nifi-api > or slf4j). > On Tue, Oct 16, 2018 at 3:47 PM John McGinn > > wrote: > > > > I have a > directory /home/user/nifi-nars, which is listed in the > nifi.properties file located under the nifi-assembly > directory from the nifi-master code. That's where I > redropped my NAR file at. > > > > The error was "due to uncaught > Exception: java.lang.NoClassDefFoundError: > org/apache/commons/lang3/StringUtils". I added a > provided dependency of version 3.4 for commons-lang3 in my > processors pom.xml. That worked initially, but with the > redropping of the NAR file, the error occurs. The stacktrace > points to the session.get() lambda function trying to use > StringUtils.isBlank(). (Again, this is a copy and renamed > class of the Wait Processor. Trying to turn it into a Yield, > as it were, hold unless it's free to move forward.) > > > > > On Tue, 10/16/18, Bryan Bende > wrote: > > > > Subject: > Re: Compiling custom processor > > To: dev@nifi.apache.org > > Date: Tuesday, October 16, 2018, 3:34 > PM > > > > There > shouldn't be any issue > > doing > that, generally you just copy the > > > new > > NAR into the lib directory and > restart. > > > > What > were the specifics of the class not found > > error? > > > > On Tue, Oct 16, 2018 at > > 3:24 PM John McGinn > > wrote: > > > > > > And I'm > > > back. > > > > > > > So, I had my > > processor running, > no errors, so things were good. > > > > > > > I then add 2 if > > statements with logger messages, run the > same mvn command, > > copied the new NAR > on top of the old one, same versionId and > > all, and now I get a class not found >
Re: Compiling custom processor
That is accurate. Generally the intention isn't really to extend processors across NARs. It is better to create a shared module with a base class that both processors can extend from, or utility code they can both call, but in the case that shared module doesn't exist then the main option is to copy over the code you need. On Wed, Oct 17, 2018 at 2:52 PM John McGinn wrote: > > Thanks Bryan. > > That was a mistake on my part. I thought that I could use part of the NiFi > standard processors in my custom processor. I suppose this also means it's > not possible to extend a standard processor class, say Wait, and override a > method, for instance, onTrigger(), to do different work. Instead, as you > state, I should copy the portions I would need to my custom processor. Is > that accurate? > > In the end, as I was looking through how to modify Wait, I think it is bigger > than the need that I have, so I restarted with a new generated processor > project, and just added the cache service, and appropriate relationships, and > simple logic to control flow through my processor. I'll work on getting a > github account and uploading my simple processor. > > Thanks for the assistance > John McGinn > > -------- > On Tue, 10/16/18, Bryan Bende wrote: > > Subject: Re: Compiling custom processor > To: figgie...@sbcglobal.net > Date: Tuesday, October 16, 2018, 4:45 PM > > You shouldn't really try to > depend on code inside other NARs like > standard processors, you'll want to copy > WaitNotifyProtocol into your > own NAR. > On > Tue, Oct 16, 2018 at 4:40 PM John McGinn > wrote: > > > > The > commons-lang3-3.7.jar file is located in the lib/bootstrap > directory, therefore, I figured it could be considered > provided. I've since change it to normal scope, and it > is included in my NAR and that error goes away. So, this > > then leans on the next error I get, which > is no class found for the WaitNotifyProtocol in > nifi.processors.standard. Is there an easy way to figure out > what NiFi class/object I'm using, and what NAR should be > listed as provided? I tried to add > nifi-standard-processors-nar, but that doesn't exist for > maven, nor does it exist in the lib directory. I looked > inside the nifi-standard-nar NAR file, and the > nifi-standard-processors is there, and inside that is > WaitNotifyProtocol, but yet, my maven won't build if I > have nifi-standard-nar listed, either with type of NAR, or > scope of provided. > > > > > On Tue, 10/16/18, Bryan Bende > wrote: > > > > Subject: > Re: Compiling custom processor > > To: dev@nifi.apache.org, > figgie...@sbcglobal.net > > Date: Tuesday, October 16, 2018, 4:01 > PM > > > > Any reason > why the commons-lang3 > > dependency is > provided and not normal > > compile > scope? > > > > Generally > the only cases where a dependency > > > should be provided are > > when a parent > NAR > > provides it (the API scenario > earlier), or when it > > is a jar > directly in lib which means it is on > > > the classpath of > > everything (like > nifi-api > > or slf4j). > > On Tue, Oct 16, 2018 at 3:47 PM John > McGinn > > > > wrote: > > > > > > I have a > > > directory /home/user/nifi-nars, which is listed in the > > nifi.properties file located under the > nifi-assembly > > directory from the > nifi-master code. That's where I > > > redropped my NAR file at. > > > > > > The error was "due to > uncaught > > Exception: > java.lang.NoClassDefFoundError: > > > org/apache/commons/lang3/StringUtils". I added a > > provided dependency of version 3.4 for > commons-lang3 in my > > processors > pom.xml. That worked initially, but with the > > redropping of the NAR file, the error > occurs. The stacktrace > > points to the > session.get() lambda function trying to use > > StringUtils.isBlank(). (Again, this is a > copy and renamed > > class of the Wait > Processor. Trying to turn it into a Yield, > > as it were, hold unless it's free to > move forward.) > > > > > > > > > On Tue, 10/16/18, Bryan Bende > > > wrote: > > > > > > Subject: > > > Re: Compiling custom processo
