org.camunda.bpm.engine.impl.scripting.engine
Class ScriptingEngines

java.lang.Object
  org.camunda.bpm.engine.impl.scripting.engine.ScriptingEngines

public class ScriptingEngines
extends Object

Manager for JSR-223 ScriptEngine handling.

Resolving a script engine: This class supports resolving a script engine for a given 'language name' (eg. 'groovy'). If the configuration option enableScriptEngineCaching is set to true, the class will attempt to cache 'cachable' script engines. We assume a ScriptEngine is 'cachable' if it declares to be threadsafe (see isCachable(ScriptEngine))

Custom Bindings: this class supports custom Bindings implementations through the scriptBindingsFactory. See ScriptBindingsFactory.

Author:

Tom Baeyens, Daniel Meyer

Field Summary

protected Map<String,ScriptEngine>	cachedEngines
static String	DEFAULT_SCRIPTING_LANGUAGE
protected boolean	enableScriptEngineCaching
static String	GROOVY_SCRIPTING_LANGUAGE
protected ScriptBindingsFactory	scriptBindingsFactory

Constructor Summary

ScriptingEngines(ScriptBindingsFactory scriptBindingsFactory)

ScriptingEngines(ScriptEngineManager scriptEngineManager)

Method Summary

ScriptingEngines	addScriptEngineFactory(ScriptEngineFactory scriptEngineFactory)
CompiledScript	compile(String language, String src) Used to compile a script provided as String into an engine-specific CompiledScript.
protected void	configureGroovyScriptEngine(ScriptEngine scriptEngine) Allows providing custom configuration for the groovy script engine.
Bindings	createBindings(ScriptEngine scriptEngine, VariableScope variableScope) override to build a spring aware ScriptingEngines
Set<String>	getAllSupportedLanguages()
protected ScriptEngine	getCachedScriptEngine(String language) Returns a cached script engine or creates a new script engine if no such engine is currently cached.
ScriptBindingsFactory	getScriptBindingsFactory()
ScriptEngine	getScriptEngineForLanguage(String language) Loads the given script engine by language name.
protected boolean	isCachable(ScriptEngine scriptEngine) Allows checking whether the script engine can be cached.
boolean	isEnableScriptEngineCaching()
void	setEnableScriptEngineCaching(boolean cacheScriptEngines)
void	setScriptBindingsFactory(ScriptBindingsFactory scriptBindingsFactory)
void	setScriptEngineFactories(List<ScriptEngineFactory> scriptEngineFactories)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_SCRIPTING_LANGUAGE

public static final String DEFAULT_SCRIPTING_LANGUAGE

See Also:

Constant Field Values

GROOVY_SCRIPTING_LANGUAGE

public static final String GROOVY_SCRIPTING_LANGUAGE

See Also:

Constant Field Values

scriptBindingsFactory

protected ScriptBindingsFactory scriptBindingsFactory

cachedEngines

protected Map<String,ScriptEngine> cachedEngines

enableScriptEngineCaching

protected boolean enableScriptEngineCaching

Constructor Detail

ScriptingEngines

public ScriptingEngines(ScriptBindingsFactory scriptBindingsFactory)

ScriptingEngines

public ScriptingEngines(ScriptEngineManager scriptEngineManager)

Method Detail

setEnableScriptEngineCaching

public void setEnableScriptEngineCaching(boolean cacheScriptEngines)

isEnableScriptEngineCaching

public boolean isEnableScriptEngineCaching()

addScriptEngineFactory

public ScriptingEngines addScriptEngineFactory(ScriptEngineFactory scriptEngineFactory)

setScriptEngineFactories

public void setScriptEngineFactories(List<ScriptEngineFactory> scriptEngineFactories)

compile

public CompiledScript compile(String language,
                              String src)

Used to compile a script provided as String into an engine-specific CompiledScript.

Note on caching of compiled scripts: only cache the returned script if enableScriptEngineCaching is set to 'true'. Depending on the implementation, the compiled script will keep references to the script engine which created it.

Parameters:

language - the script language in which the script is written

src - a string of the source of the script

Returns:

a CompiledScript or null if script engine can be found but does not support compilation.

Throws:

ProcessEngineException - if no ScriptEngine can be resolved for the provided language or if the script cannot be compiled (syntax error ...).

getScriptEngineForLanguage

public ScriptEngine getScriptEngineForLanguage(String language)

Loads the given script engine by language name. Will throw an exception if no script engine can be loaded for the given language name.

Parameters:

language - the name of the script language to lookup an implementation for

Returns:

the script engine

Throws:

ProcessEngineException - if no such engine can be found.

getAllSupportedLanguages

public Set<String> getAllSupportedLanguages()

getCachedScriptEngine

protected ScriptEngine getCachedScriptEngine(String language)

Returns a cached script engine or creates a new script engine if no such engine is currently cached.

Parameters:

language - the language (such as 'groovy' for the script engine)

Returns:

the cached engine or null if no script engine can be created for the given language

isCachable

protected boolean isCachable(ScriptEngine scriptEngine)

Allows checking whether the script engine can be cached.

Parameters:

scriptEngine - the script engine to check.

Returns:

true if the script engine may be cached.

configureGroovyScriptEngine

protected void configureGroovyScriptEngine(ScriptEngine scriptEngine)

Allows providing custom configuration for the groovy script engine.

Parameters:

scriptEngine - the groovy script engine to configure.

createBindings

public Bindings createBindings(ScriptEngine scriptEngine,
                               VariableScope variableScope)

override to build a spring aware ScriptingEngines

Parameters:

engineBindings -

scriptEngine -

getScriptBindingsFactory

public ScriptBindingsFactory getScriptBindingsFactory()

setScriptBindingsFactory

public void setScriptBindingsFactory(ScriptBindingsFactory scriptBindingsFactory)