org.apache.nifi.service.lookup

Class AbstractSingleAttributeBasedControllerServiceLookup<S extends ControllerService>

java.lang.Object

org.apache.nifi.components.AbstractConfigurableComponent

org.apache.nifi.controller.AbstractControllerService

org.apache.nifi.service.lookup.AbstractSingleAttributeBasedControllerServiceLookup<S>

Type Parameters:

S - The type of service to be looked up

All Implemented Interfaces:

ConfigurableComponent, ControllerService

public abstract class AbstractSingleAttributeBasedControllerServiceLookup<S extends ControllerService>
extends AbstractControllerService

A lookup ControllerService that can choose one (from probably multiple) ControllerServices of the given type S.

Selection is based on a single String lookup key.

Lookup key is provided as a value in an attribute map (usually coming form a flowfile) with a predefined key (see getLookupAttribute()).

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<String,S>	serviceMap

Constructor Summary

Constructors

Constructor and Description
AbstractSingleAttributeBasedControllerServiceLookup()

Method Summary

Modifier and Type	Method and Description
protected Collection<ValidationResult>	customValidate(ValidationContext context)
protected abstract String	getLookupAttribute()
protected String	getServiceName()
abstract Class<S>	getServiceType()
protected PropertyDescriptor	getSupportedDynamicPropertyDescriptor(String propertyDescriptorName)
protected PropertyDescriptor	lookupKeyPropertyDescriptor(String propertyDescriptorName)
S	lookupService(Map<String,String> attributes) Returns a ControllerService (of type S) based on the provided attributes map (usually by retrieving a lookup attribute from it via getLookupAttribute() and use it to identify the appropriate service).
void	onDisabled()
void	onEnabled(ConfigurationContext context)
private Collection<ValidationResult>	validateForAtLeastOneService(ValidationContext context)

Methods inherited from class org.apache.nifi.controller.AbstractControllerService

abstractClearConfigContext, abstractStoreConfigContext, disabled, enabled, getConfigurationContext, getControllerServiceLookup, getIdentifier, getLogger, getNodeTypeProvider, getProperty, getStateManager, init, initialize, isEnabled

Methods inherited from class org.apache.nifi.components.AbstractConfigurableComponent

equals, getPropertyDescriptor, getPropertyDescriptors, getSupportedPropertyDescriptors, hashCode, onPropertyModified, toString, validate

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.nifi.controller.ControllerService

isStateful

Methods inherited from interface org.apache.nifi.components.ConfigurableComponent

getPropertyDescriptor, getPropertyDescriptors, onPropertyModified, validate

Field Detail

serviceMap

protected volatile Map<String,S extends ControllerService> serviceMap

Constructor Detail

AbstractSingleAttributeBasedControllerServiceLookup

public AbstractSingleAttributeBasedControllerServiceLookup()

Method Detail

getServiceType

public abstract Class<S> getServiceType()

Returns:

the Class that represents the type of service that will be returned by lookupService(Map)

getLookupAttribute

protected abstract String getLookupAttribute()

Returns:

the name of attribute (usually from a flowfile) the value of which serves as the lookup key for the desired service (of type S)

lookupService

public S lookupService(Map<String,String> attributes)

Returns a ControllerService (of type S) based on the provided attributes map (usually by retrieving a lookup attribute from it via getLookupAttribute() and use it to identify the appropriate service).

Parameters:

attributes - Map containing the lookup attribute based on which ControllerService is chosen

Returns:

the chosen ControllerService

onEnabled

@OnEnabled
public void onEnabled(ConfigurationContext context)

onDisabled

@OnDisabled
public void onDisabled()

getSupportedDynamicPropertyDescriptor

protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(String propertyDescriptorName)

Overrides:

getSupportedDynamicPropertyDescriptor in class AbstractConfigurableComponent

customValidate

protected Collection<ValidationResult> customValidate(ValidationContext context)

Overrides:

customValidate in class AbstractConfigurableComponent

lookupKeyPropertyDescriptor

protected PropertyDescriptor lookupKeyPropertyDescriptor(String propertyDescriptorName)

validateForAtLeastOneService

private Collection<ValidationResult> validateForAtLeastOneService(ValidationContext context)

getServiceName

protected String getServiceName()