Hi
I have been trying to write a simple Cache Controller Service that uses a Map
to hold <String, String> key/value pairs. I am using nifi-0.1.0-incubating. I
have created an Interface called CacheService which extends
ControllerService.public interface CacheService extends ControllerService {
I have created an implementation called StandardCacheService which is as
follows:
public class StandardCacheService extends AbstractControllerService implements
CacheService {
I have compiled the StandardCacheService and created a nar which I have then
put into my NiFi lib directory, my StandardCacheService Controller Service
appears in the Controller services tab of the NiFi Flow Settings panel, I can
edit it and enable it. Also there are no abnormal log messages.
However, when I try to configure the CacheService in my test Processor, again I
get no errors but when I cannot see my StandardCacheService. My processor has
the following snippets to implement the Cache Service/Controller:
public static final PropertyDescriptor CACHE_SERVICE = new
PropertyDescriptor.Builder()
.name("Cache Service")
.description("The Controller Service to use in order to obtain a Cache
Service")
.required(false)
.identifiesControllerService(CacheService.class)
.build();
final CacheService cache =
context.getProperty(CACHE_SERVICE).asControllerService(CacheService.class);
When configuring the processor, the 'Cache Service' drop down doesn't show a
populated list showing my StandardCacheService, but it does allow me to create
a new service, the resulting panel allows me to then select
StandardCacheService. When I select 'create' I get a UUID value in the
Value property of the Configure Processor panel. When I then apply this the
processor shows a yellow triangle, when I hover over it I get the following
message:
'Cache Service validated against <UUID> is invalid because Invalid Controller
service <UUID> is not a valid Controller service Identifier or does not
reference the correct type of Controller service.'
Can you help please
Many thanksDave
