Hi,
I am running into a problem with deploying a custom controller service to NiFi (I am using the latest version of NIfi 1.12 as of writing this). Now what I am trying to do is to create a custom controller service that would allow me to access a Virtuoso DB instance (similarly to DBCPConnectionPool). This controller relies on 2 external jar files (provided by Virtuoso) that I have placed inside a /libs folder under the module that implements the interface of my service. I have pointed to these jars as dependencies in the pom.xml of that same module and maven is able to import them. Furthermore, I am able to successfully compile and run a JUnit test of my implementation of the service which consists of simply getting a connection and checking if it is open.
The problem arises when I compile my service into a NAR and then deploy that service in NiFi. NiFi is able to detect it but when I try to enable it, it throws a NoClassDefFoundError that is related to these external jars. Now I am considering doing similarly to DBCPConnectionPool and create a property to point to these jars and load them externally, however, I simply do not understand what is causing the problem and I am too curious to let it go, I am also concerned that this approach may not be viable for these jars. So i am curious if someone can point me in the right way.
Here is my folder structure:
Here is the code I am trying to execute @OnEnabled. which passes JUnit
@OnEnabled
public void onEnabled(final ConfigurationContext context) {
getLogger().info("Initializing Virtuoso Repository");
try {
ConnectionPoolDataSource dataSource = new VirtuosoConnectionPoolDataSource();
((VirtuosoConnectionPoolDataSource)dataSource).setCharset(context.getProperty(REPOSITORY_CHARSET).getValue());
((VirtuosoConnectionPoolDataSource)dataSource).setServerName(context.getProperty(REPOSITORY_SERVER).getValue());
((VirtuosoConnectionPoolDataSource)dataSource).setInitialPoolSize(Integer.parseInt(context.getProperty(REPOSITORY_CONNECTIONPOOLSIZE).getValue()));
((VirtuosoConnectionPoolDataSource)dataSource).setMaxPoolSize(Integer.parseInt(context.getProperty(REPOSITORY_MAXCONNECTIONPOOLSIZE).getValue()));
repository = new VirtuosoRepository(dataSource, context.getProperty(REPOSITORY_DEFAULTGRAPH).getValue(), true);
repository.initialize();
}catch (Exception e){
getLogger().error("Unable to Initialize Virtuoso Repository", e);
}
}
Here is the pom where/how I declare the jar dependencies (This is where I am assuming the error might be)
And this is the log of the error I am getting when I try to enable it from NiFi:
2020-08-31 13:50:03,567 ERROR [Timer-Driven Process Thread-4] o.a.n.c.s.StandardControllerServiceNode Failed to invoke @OnEnabled method of StandardMyService[id=43ef57e8-0174-1000-843d-d32a07ba02bb] due to java.lang.NoClassDefFoundError: virtuoso/jdbc4/VirtuosoConnectionPoolDataSource
2020-08-31 13:50:03,567 ERROR [Timer-Driven Process Thread-4] e.e.c.dct.Virtuoso.StandardMyService StandardMyService[id=43ef57e8-0174-1000-843d-d32a07ba02bb] Could not Shut Down Repository: java.lang.NullPointerException
java.lang.NullPointerException: null
at eu.everis.cordis.dct.Virtuoso.StandardMyService.shutdown(StandardMyService.java:187)
at jdk.internal.reflect.GeneratedMethodAccessor376.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.apache.nifi.util.ReflectionUtils.invokeMethodsWithAnnotations(ReflectionUtils.java:142)
Hope someone can explain where the problem comes from,
BR,
Tino
