org.apache.nifi.processors.script

Class InvokeScriptedProcessor

java.lang.Object

org.apache.nifi.components.AbstractConfigurableComponent

org.apache.nifi.processor.AbstractSessionFactoryProcessor

org.apache.nifi.processors.script.AbstractScriptProcessor

org.apache.nifi.processors.script.InvokeScriptedProcessor

All Implemented Interfaces:

ConfigurableComponent, Processor

@Tags(value={"script","invoke","groovy","python","jython","jruby","ruby","javascript","js","lua","luaj"})
@CapabilityDescription(value="Experimental - Invokes a script engine for a Processor defined in the given script. The script must define a valid class that implements the Processor interface, and it must set a variable \'processor\' to an instance of the class. Processor methods such as onTrigger() will be delegated to the scripted Processor instance. Also any Relationships or PropertyDescriptors defined by the scripted processor will be added to the configuration dialog.  Experimental: Impact of sustained usage not yet verified.")
@DynamicProperty(name="A script engine property to update",
                 value="The value to set it to",
                 supportsExpressionLanguage=true,
                 description="Updates a script engine property specified by the Dynamic Property\'s key with the value specified by the Dynamic Property\'s value")
@SeeAlso(value=ExecuteScript.class)
public class InvokeScriptedProcessor
extends AbstractScriptProcessor

Field Summary

Fields

Modifier and Type	Field and Description
private AtomicReference<Processor>	processor
private ScriptEngine	scriptEngine
private AtomicBoolean	scriptNeedsReload
private AtomicReference<Collection<ValidationResult>>	validationResults

Fields inherited from class org.apache.nifi.processors.script.AbstractScriptProcessor

descriptors, engineQ, isInitialized, modules, MODULES, REL_FAILURE, REL_SUCCESS, SCRIPT_BODY, SCRIPT_ENGINE, SCRIPT_FILE, scriptBody, scriptEngineConfiguratorMap, scriptEngineFactoryMap, scriptEngineName, scriptPath

Constructor Summary

Constructors

Constructor and Description
InvokeScriptedProcessor()

Method Summary

Methods

Modifier and Type	Method and Description
protected Collection<ValidationResult>	customValidate(ValidationContext context) Invokes the validate() routine provided by the script, allowing for custom validation code.
Set<Relationship>	getRelationships() Returns the valid relationships for this processor.
protected PropertyDescriptor	getSupportedDynamicPropertyDescriptor(String propertyDescriptorName) Returns a PropertyDescriptor for the given name.
protected List<PropertyDescriptor>	getSupportedPropertyDescriptors() Returns a list of property descriptors supported by this processor.
void	onPropertyModified(PropertyDescriptor descriptor, String oldValue, String newValue) Handles changes to this processor's properties.
void	onTrigger(ProcessContext context, ProcessSessionFactory sessionFactory) Invokes the onTrigger() method of the scripted processor.
private boolean	reloadScript(String scriptBody) Reloads the script Processor.
private boolean	reloadScriptBody(String scriptBody) Reloads the script defined by the given string
private boolean	reloadScriptFile(String scriptPath) Reloads the script located at the given path
void	setup()
void	setup(ProcessContext context) Performs setup operations when the processor is scheduled to run.
void	stop()

Methods inherited from class org.apache.nifi.processors.script.AbstractScriptProcessor

createResources, createScriptEngine, createScriptEngineModuleClassLoader, isFile, setup, setupEngines

Methods inherited from class org.apache.nifi.processor.AbstractSessionFactoryProcessor

getControllerServiceLookup, getIdentifier, getLogger, init, initialize, isConfigurationRestored, isScheduled, toString, updateConfiguredRestoredTrue, updateScheduledFalse, updateScheduledTrue

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

equals, getPropertyDescriptor, getPropertyDescriptors, hashCode, validate

Methods inherited from class java.lang.Object

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

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

getPropertyDescriptor, getPropertyDescriptors, validate

Field Detail

processor

private final AtomicReference<Processor> processor

validationResults

private final AtomicReference<Collection<ValidationResult>> validationResults

scriptNeedsReload

private AtomicBoolean scriptNeedsReload

scriptEngine

private ScriptEngine scriptEngine

Constructor Detail

InvokeScriptedProcessor

public InvokeScriptedProcessor()

Method Detail

getRelationships

public Set<Relationship> getRelationships()

Returns the valid relationships for this processor. SUCCESS and FAILURE are always returned, and if the script processor has defined additional relationships, those will be added as well.

Specified by:

getRelationships in interface Processor

Overrides:

getRelationships in class AbstractSessionFactoryProcessor

Returns:

a Set of Relationships supported by this processor

getSupportedPropertyDescriptors

protected List<PropertyDescriptor> getSupportedPropertyDescriptors()

Returns a list of property descriptors supported by this processor. The list always includes properties such as script engine name, script file name, script body name, script arguments, and an external module path. If the scripted processor also defines supported properties, those are added to the list as well.

Overrides:

getSupportedPropertyDescriptors in class AbstractConfigurableComponent

Returns:

a List of PropertyDescriptor objects supported by this processor

getSupportedDynamicPropertyDescriptor

protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(String propertyDescriptorName)

Returns a PropertyDescriptor for the given name. This is for the user to be able to define their own properties which will be available as variables in the script

Overrides:

getSupportedDynamicPropertyDescriptor in class AbstractConfigurableComponent

Parameters:

propertyDescriptorName - used to lookup if any property descriptors exist for that name

Returns:

a PropertyDescriptor object corresponding to the specified dynamic property name

setup

@OnScheduled
public void setup(ProcessContext context)

Performs setup operations when the processor is scheduled to run. This includes evaluating the processor's properties, as well as reloading the script (from file or the "Script Body" property)

Parameters:

context - the context in which to perform the setup operations

setup

public void setup()

onPropertyModified

public void onPropertyModified(PropertyDescriptor descriptor,
                      String oldValue,
                      String newValue)

Handles changes to this processor's properties. If changes are made to script- or engine-related properties, the script will be reloaded.

Specified by:

onPropertyModified in interface ConfigurableComponent

Overrides:

onPropertyModified in class AbstractConfigurableComponent

Parameters:

descriptor - of the modified property

oldValue - non-null property value (previous)

newValue - the new property value or if null indicates the property

reloadScriptFile

private boolean reloadScriptFile(String scriptPath)

Reloads the script located at the given path

Parameters:

scriptPath - the path to the script file to be loaded

Returns:

true if the script was loaded successfully; false otherwise

reloadScriptBody

private boolean reloadScriptBody(String scriptBody)

Reloads the script defined by the given string

Parameters:

scriptBody - the contents of the script to be loaded

Returns:

true if the script was loaded successfully; false otherwise

reloadScript

private boolean reloadScript(String scriptBody)

Reloads the script Processor. This must be called within the lock.

Parameters:

scriptBody - An input stream associated with the script content

Returns:

Whether the script was successfully reloaded

customValidate

protected Collection<ValidationResult> customValidate(ValidationContext context)

Invokes the validate() routine provided by the script, allowing for custom validation code. This method assumes there is a valid Processor defined in the script and it has been loaded by the InvokeScriptedProcessor processor

Overrides:

customValidate in class AbstractScriptProcessor

Parameters:

context - The validation context to be passed into the custom validate method

Returns:

A collection of ValidationResults returned by the custom validate method

onTrigger

public void onTrigger(ProcessContext context,
             ProcessSessionFactory sessionFactory)
               throws ProcessException

Invokes the onTrigger() method of the scripted processor. If the script failed to reload, the processor yields until the script can be reloaded successfully. If the scripted processor's onTrigger() method throws an exception, a ProcessException will be thrown. If no processor is defined by the script, an error is logged with the system.

Parameters:

context - provides access to convenience methods for obtaining property values, delaying the scheduling of the processor, provides access to Controller Services, etc.

sessionFactory - provides access to a ProcessSessionFactory, which can be used for accessing FlowFiles, etc.

Throws:

ProcessException - if the scripted processor's onTrigger() method throws an exception

stop

@OnStopped
public void stop()

Overrides:

stop in class AbstractScriptProcessor