Class FlowController_ImplBase
- java.lang.Object
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- org.apache.uima.flow.FlowController_ImplBase
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- All Implemented Interfaces:
FlowController
- Direct Known Subclasses:
CasFlowController_ImplBase
,JCasFlowController_ImplBase
public abstract class FlowController_ImplBase extends Object implements FlowController
Implementation base class for FlowControllers. Normally developers do not extend this class directly. Instead useJCasFlowController_ImplBase
orCasFlowController_ImplBase
, depending on which CAS interface you would like to use.This class implements the
initialize(FlowControllerContext)
method and stores theFlowControllerContext
in a private field where it can be accessed via thegetContext()
method.This class also provides a "dumb" implementation of the
reconfigure()
method, which simply callsdestroy()
followed byinitialize(FlowControllerContext)
. Developers of FlowControllers with expensive initialization logic should override this method and provide a more intelligent implementation.
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Constructor Summary
Constructors Constructor Description FlowController_ImplBase()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addAnalysisEngines(Collection<String> aKeys)
Does nothing by default.void
batchProcessComplete()
Completes the processing of a batch of CASes.void
collectionProcessComplete()
Notifies this component that processing of an entire collection has been completed.void
destroy()
Frees all resources held by this FlowController.protected FlowControllerContext
getContext()
Gets the FlowControllerContext for this FlowController.void
initialize(FlowControllerContext aContext)
Performs any startup tasks required by this component.void
reconfigure()
Alerts this FlowController that the values of its configuration parameters or external resources have changed.void
removeAnalysisEngines(Collection<String> aKeys)
Throws an AnalysisEngineProcessException by default.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.apache.uima.flow.FlowController
computeFlow, getRequiredCasInterface
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Method Detail
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initialize
public void initialize(FlowControllerContext aContext) throws ResourceInitializationException
Description copied from interface:FlowController
Performs any startup tasks required by this component. The framework calls this method only once, just after the FlowController has been instantiated.The framework supplies this FlowController with a reference to the
FlowControllerContext
that it will use, for example to access configuration settings or resources. This FlowController should store a reference to this Context for later use.- Specified by:
initialize
in interfaceFlowController
- Parameters:
aContext
- Provides access to services and resources managed by the framework. This includes configuration parameters, logging, and access to external resources. Also provides the FlowController with the metadata of all of the AnalysisEngines that are possible targets for routing CASes.- Throws:
ResourceInitializationException
- if the FlowController cannot initialize successfully.
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reconfigure
public void reconfigure() throws ResourceInitializationException, ResourceConfigurationException
Description copied from interface:FlowController
Alerts this FlowController that the values of its configuration parameters or external resources have changed. This FlowController should re-read its configuration from theUimaContext
and take appropriate action to reconfigure itself.In the abstract base classes provided by the framework, this is generally implemented by calling
destroy
followed byinitialize
. If a more efficient implementation is needed, you can override that implementation.- Specified by:
reconfigure
in interfaceFlowController
- Throws:
ResourceInitializationException
- if this component encounters a problem in reinitializing itself from the new configurationResourceConfigurationException
- if the new configuration is invalid
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batchProcessComplete
public void batchProcessComplete() throws AnalysisEngineProcessException
Description copied from interface:FlowController
Completes the processing of a batch of CASes. The size of a batch is determined based on configuration provided by the application that is using this component. The purpose ofbatchProcessComplete
is to give this component the change to flush information from memory to persistent storage. In the event of an error, this allows the processing to be restarted from the end of the last completed batch.If this component's descriptor declares that it is
recoverable
, then this component is required to be restartable from the end of the last completed batch.- Specified by:
batchProcessComplete
in interfaceFlowController
- Throws:
AnalysisEngineProcessException
- if this component encounters a problem in flushing its state to persistent storage
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collectionProcessComplete
public void collectionProcessComplete() throws AnalysisEngineProcessException
Description copied from interface:FlowController
Notifies this component that processing of an entire collection has been completed. In this method, this component should finish writing any output relating to the current collection.- Specified by:
collectionProcessComplete
in interfaceFlowController
- Throws:
AnalysisEngineProcessException
- if this component encounters a problem in its end-of-collection processing
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destroy
public void destroy()
Description copied from interface:FlowController
Frees all resources held by this FlowController. The framework calls this method only once, when it is finished using this component.- Specified by:
destroy
in interfaceFlowController
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addAnalysisEngines
public void addAnalysisEngines(Collection<String> aKeys)
Does nothing by default. Subclasses may override this to support adding new AnalysisEngines to the flow.- Specified by:
addAnalysisEngines
in interfaceFlowController
- Parameters:
aKeys
- a Collection of Strings, each of which is the key of an Analysis Engine to which CASes can be routed. These are the same keys as used inFlowControllerContext.getAnalysisEngineMetaDataMap()
.- See Also:
FlowController.addAnalysisEngines(java.util.Collection)
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removeAnalysisEngines
public void removeAnalysisEngines(Collection<String> aKeys) throws AnalysisEngineProcessException
Throws an AnalysisEngineProcessException by default. Subclasses may override this to support removing AnalysisEngines from the flow.- Specified by:
removeAnalysisEngines
in interfaceFlowController
- Parameters:
aKeys
- a Collection of Strings, each of which is the key of an Analysis Engine to which CASes may no longer be routed.- Throws:
AnalysisEngineProcessException
- if the FlowController cannot continue with these Analysis Engines removed, or doesn't support removing Analysis Engines at all.- See Also:
FlowController.removeAnalysisEngines(java.util.Collection)
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getContext
protected FlowControllerContext getContext()
Gets the FlowControllerContext for this FlowController. This provides access to configuration parameters, resources, and also to metadata for each AnalysisEngine that is available for this FlowController to route CASes to.- Returns:
- the FlowControllerContext for this FlowController
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