org.apache.nifi.processors.script

Class AbstractScriptProcessor

java.lang.Object

org.apache.nifi.components.AbstractConfigurableComponent

org.apache.nifi.processor.AbstractSessionFactoryProcessor

org.apache.nifi.processors.script.AbstractScriptProcessor

All Implemented Interfaces:

ConfigurableComponent, Processor

Direct Known Subclasses:

ExecuteScript, InvokeScriptedProcessor

public abstract class AbstractScriptProcessor
extends AbstractSessionFactoryProcessor

This class contains variables and methods common to scripting processors

Field Summary

Fields

Modifier and Type	Field and Description
protected List<PropertyDescriptor>	descriptors
protected BlockingQueue<ScriptEngine>	engineQ
protected AtomicBoolean	isInitialized
protected String[]	modules
static PropertyDescriptor	MODULES
static Relationship	REL_FAILURE
static Relationship	REL_SUCCESS
static PropertyDescriptor	SCRIPT_BODY
static PropertyDescriptor	SCRIPT_ENGINE
static PropertyDescriptor	SCRIPT_FILE
protected String	scriptBody
protected Map<String,ScriptEngineConfigurator>	scriptEngineConfiguratorMap
protected Map<String,ScriptEngineFactory>	scriptEngineFactoryMap
protected String	scriptEngineName
protected String	scriptPath

Constructor Summary

Constructors

Constructor and Description
AbstractScriptProcessor()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	createResources() This method creates all resources needed for the script processor to function, such as script engines, script file reloader threads, etc.
protected ScriptEngine	createScriptEngine() Provides a ScriptEngine corresponding to the currently selected script engine name.
protected ClassLoader	createScriptEngineModuleClassLoader(URL[] modules) Creates a classloader to be used by the selected script engine and the provided script file.
protected Collection<ValidationResult>	customValidate(ValidationContext validationContext) Custom validation for ensuring exactly one of Script File or Script Body is populated
protected boolean	isFile(String path) Determines whether the given path refers to a valid file
void	setup(int numberOfScriptEngines) Performs common setup operations when the processor is scheduled to run.
protected void	setupEngines(int numberOfScriptEngines) Configures the specified script engine.
void	stop()

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

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

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.nifi.processor.Processor

onTrigger

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

getPropertyDescriptor, getPropertyDescriptors, onPropertyModified, validate

Field Detail

REL_SUCCESS

public static final Relationship REL_SUCCESS

REL_FAILURE

public static final Relationship REL_FAILURE

SCRIPT_ENGINE

public static PropertyDescriptor SCRIPT_ENGINE

SCRIPT_FILE

public static final PropertyDescriptor SCRIPT_FILE

SCRIPT_BODY

public static final PropertyDescriptor SCRIPT_BODY

MODULES

public static final PropertyDescriptor MODULES

scriptEngineConfiguratorMap

protected final Map<String,ScriptEngineConfigurator> scriptEngineConfiguratorMap

isInitialized

protected final AtomicBoolean isInitialized

scriptEngineFactoryMap

protected Map<String,ScriptEngineFactory> scriptEngineFactoryMap

scriptEngineName

protected String scriptEngineName

scriptPath

protected String scriptPath

scriptBody

protected String scriptBody

modules

protected String[] modules

descriptors

protected List<PropertyDescriptor> descriptors

engineQ

protected BlockingQueue<ScriptEngine> engineQ

Constructor Detail

AbstractScriptProcessor

public AbstractScriptProcessor()

Method Detail

customValidate

protected Collection<ValidationResult> customValidate(ValidationContext validationContext)

Custom validation for ensuring exactly one of Script File or Script Body is populated

Overrides:

customValidate in class AbstractConfigurableComponent

Parameters:

validationContext - provides a mechanism for obtaining externally managed values, such as property values and supplies convenience methods for operating on those values

Returns:

A collection of validation results

createResources

protected void createResources()

This method creates all resources needed for the script processor to function, such as script engines, script file reloader threads, etc.

isFile

protected boolean isFile(String path)

Determines whether the given path refers to a valid file

Parameters:

path - a path to a file

Returns:

true if the path refers to a valid file, false otherwise

setup

public void setup(int numberOfScriptEngines)

Performs common setup operations when the processor is scheduled to run. This method assumes the member variables associated with properties have been filled.

setupEngines

protected void setupEngines(int numberOfScriptEngines)

Configures the specified script engine. First, the engine is loaded and instantiated using the JSR-223 javax.script APIs. Then, if any script configurators have been defined for this engine, their init() method is called, and the configurator is saved for future calls.

See Also:

ScriptEngineConfigurator

createScriptEngine

protected ScriptEngine createScriptEngine()

Provides a ScriptEngine corresponding to the currently selected script engine name. ScriptEngineManager.getEngineByName() doesn't use find ScriptEngineFactory.getName(), which is what we used to populate the list. So just search the list of factories until a match is found, then create and return a script engine.

Returns:

a Script Engine corresponding to the currently specified name, or null if none is found.

createScriptEngineModuleClassLoader

protected ClassLoader createScriptEngineModuleClassLoader(URL[] modules)

Creates a classloader to be used by the selected script engine and the provided script file. This classloader has this class's classloader as a parent (versus the current thread's context classloader) and also adds the specified module URLs to the classpath. This enables scripts to use other scripts, modules, etc. without having to build them into the scripting NAR. If the parameter is null or empty, this class's classloader is returned

Parameters:

modules - An array of URLs to add to the class loader

stop

@OnStopped
public void stop()