Class DefaultGremlinScriptEngineManager
- java.lang.Object
-
- org.apache.tinkerpop.gremlin.jsr223.DefaultGremlinScriptEngineManager
-
- All Implemented Interfaces:
GremlinScriptEngineManager
- Direct Known Subclasses:
CachedGremlinScriptEngineManager
public class DefaultGremlinScriptEngineManager extends Object implements GremlinScriptEngineManager
TheScriptEngineManagerimplements a discovery, instantiation and configuration mechanism forGremlinScriptEngineclasses and also maintains a collection of key/value pairs storing state shared by all engines created by it. This class uses theServiceProvidermechanism to enumerate all the implementations ofGremlinScriptEngineFactory. TheScriptEngineManagerprovides a method to return a list of all these factories as well as utility methods which look up factories on the basis of language name, file extension and mime type. TheBindingsof key/value pairs, referred to as the "Global Scope" maintained by the manager is available to all instances of @code ScriptEngine} created by theGremlinScriptEngineManager. The values in theBindingsare generally exposed in all scripts. This class is based quite heavily on the workings of theScriptEngineManagersupplied in thejavax.scriptpackages, but adds some additional features that are specific to Gremlin and TinkerPop. Unfortunately, it's not easily possible to extendScriptEngineManagerdirectly as there certain behaviors don't appear to be be straightforward to implement and member variables are all private. It is important to note that this class is designed to provide support for "Gremlin-enabled"ScriptEngineinstances (i.e. those that extend fromGremlinScriptEngine) and is not meant to manage just anyScriptEngineinstance that may be on the path. As this is a "Gremlin"ScriptEngine, certain common imports are automatically applied when aGremlinScriptEngineis instantiated via theGremlinScriptEngineFactory.. Initial imports from gremlin-core come from theCoreImports.- Author:
- Stephen Mallette (http://stephen.genoprime.com)
-
-
Constructor Summary
Constructors Constructor Description DefaultGremlinScriptEngineManager()The effect of calling this constructor is the same as callingDefaultGremlinScriptEngineManager(Thread.currentThread().getContextClassLoader()).DefaultGremlinScriptEngineManager(ClassLoader loader)This constructor loads the implementations ofGremlinScriptEngineFactoryvisible to the givenClassLoaderusing theServiceLoadermechanism.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidaddPlugin(GremlinPlugin plugin)AddGremlinPlugininstances to customize newly createdGremlinScriptEngineinstances.Objectget(String key)Gets the value for the specified key in the global scope.BindingsgetBindings()Gets the bindings of theBindingsin global scope.List<Customizer>getCustomizers(String scriptEngineName)Get the list ofCustomizerinstances filtered by thescriptEngineName.GremlinScriptEnginegetEngineByExtension(String extension)Look up and create aGremlinScriptEnginefor a given extension.GremlinScriptEnginegetEngineByMimeType(String mimeType)Look up and create aGremlinScriptEnginefor a given mime type.GremlinScriptEnginegetEngineByName(String shortName)Looks up and creates aGremlinScriptEnginefor a given name.List<GremlinScriptEngineFactory>getEngineFactories()Returns a list whose elements are instances of all theGremlinScriptEngineFactoryclasses found by the discovery mechanism.voidput(String key, Object value)Sets the specified key/value pair in the global scope.voidregisterEngineExtension(String extension, GremlinScriptEngineFactory factory)Registers aGremlinScriptEngineFactoryto handle an extension.voidregisterEngineMimeType(String type, GremlinScriptEngineFactory factory)Registers aGremlinScriptEngineFactoryto handle a mime type.voidregisterEngineName(String name, GremlinScriptEngineFactory factory)Registers aGremlinScriptEngineFactoryto handle a language name.voidsetBindings(Bindings bindings)Stores the specifiedBindingsas a global for allGremlinScriptEngineobjects created by it.
-
-
-
Constructor Detail
-
DefaultGremlinScriptEngineManager
public DefaultGremlinScriptEngineManager()
The effect of calling this constructor is the same as callingDefaultGremlinScriptEngineManager(Thread.currentThread().getContextClassLoader()).
-
DefaultGremlinScriptEngineManager
public DefaultGremlinScriptEngineManager(ClassLoader loader)
This constructor loads the implementations ofGremlinScriptEngineFactoryvisible to the givenClassLoaderusing theServiceLoadermechanism. If loader isnull, the script engine factories that are bundled with the platform and that are in the usual extension directories (installed extensions) are loaded.
-
-
Method Detail
-
getCustomizers
public List<Customizer> getCustomizers(String scriptEngineName)
Description copied from interface:GremlinScriptEngineManagerGet the list ofCustomizerinstances filtered by thescriptEngineName.- Specified by:
getCustomizersin interfaceGremlinScriptEngineManager
-
addPlugin
public void addPlugin(GremlinPlugin plugin)
Description copied from interface:GremlinScriptEngineManagerAddGremlinPlugininstances to customize newly createdGremlinScriptEngineinstances.- Specified by:
addPluginin interfaceGremlinScriptEngineManager
-
setBindings
public void setBindings(Bindings bindings)
Stores the specifiedBindingsas a global for allGremlinScriptEngineobjects created by it. If the bindings are to be updated by multiple threads it is recommended that aConcurrentBindingsinstance is supplied.- Specified by:
setBindingsin interfaceGremlinScriptEngineManager- Throws:
IllegalArgumentException- if bindings is null.
-
getBindings
public Bindings getBindings()
Gets the bindings of theBindingsin global scope.- Specified by:
getBindingsin interfaceGremlinScriptEngineManager
-
put
public void put(String key, Object value)
Sets the specified key/value pair in the global scope. The key may not be null or empty.- Specified by:
putin interfaceGremlinScriptEngineManager- Throws:
IllegalArgumentException- if key is null or empty.
-
get
public Object get(String key)
Gets the value for the specified key in the global scope.- Specified by:
getin interfaceGremlinScriptEngineManager
-
getEngineByName
public GremlinScriptEngine getEngineByName(String shortName)
Looks up and creates aGremlinScriptEnginefor a given name. The algorithm first searches for aGremlinScriptEngineFactorythat has been registered as a handler for the specified name using theregisterEngineExtension(String, GremlinScriptEngineFactory)method. If one is not found, it searches the set ofGremlinScriptEngineFactoryinstances stored by the constructor for one with the specified name. If aScriptEngineFactoryis found by either method, it is used to create instance ofGremlinScriptEngine.- Specified by:
getEngineByNamein interfaceGremlinScriptEngineManager- Parameters:
shortName- The short name of theGremlinScriptEngineimplementation returned by theScriptEngineFactory.getNames()method.- Returns:
- A
GremlinScriptEnginecreated by the factory located in the search. Returnsnullif no such factory was found. The global scope of this manager is applied to the newly createdGremlinScriptEngine - Throws:
NullPointerException- if shortName isnull.
-
getEngineByExtension
public GremlinScriptEngine getEngineByExtension(String extension)
Look up and create aGremlinScriptEnginefor a given extension. The algorithm used bygetEngineByName(String)is used except that the search starts by looking for aGremlinScriptEngineFactoryregistered to handle the given extension usingregisterEngineExtension(String, GremlinScriptEngineFactory).- Specified by:
getEngineByExtensionin interfaceGremlinScriptEngineManager- Returns:
- The engine to handle scripts with this extension. Returns
nullif not found. - Throws:
NullPointerException- if extension isnull.
-
getEngineByMimeType
public GremlinScriptEngine getEngineByMimeType(String mimeType)
Look up and create aGremlinScriptEnginefor a given mime type. The algorithm used bygetEngineByName(String)is used except that the search starts by looking for aGremlinScriptEngineFactoryregistered to handle the given mime type usingregisterEngineMimeType(String, GremlinScriptEngineFactory).- Specified by:
getEngineByMimeTypein interfaceGremlinScriptEngineManager- Parameters:
mimeType- The given mime type- Returns:
- The engine to handle scripts with this mime type. Returns
nullif not found. - Throws:
NullPointerException- if mime-type isnull.
-
getEngineFactories
public List<GremlinScriptEngineFactory> getEngineFactories()
Returns a list whose elements are instances of all theGremlinScriptEngineFactoryclasses found by the discovery mechanism.- Specified by:
getEngineFactoriesin interfaceGremlinScriptEngineManager- Returns:
- List of all discovered
GremlinScriptEngineFactoryobjects.
-
registerEngineName
public void registerEngineName(String name, GremlinScriptEngineFactory factory)
Registers aGremlinScriptEngineFactoryto handle a language name. Overrides any such association found using the discovery mechanism.- Specified by:
registerEngineNamein interfaceGremlinScriptEngineManager- Parameters:
name- The name to be associated with theGremlinScriptEngineFactoryfactory- The class to associate with the given name.- Throws:
NullPointerException- if any of the parameters is null.
-
registerEngineMimeType
public void registerEngineMimeType(String type, GremlinScriptEngineFactory factory)
Registers aGremlinScriptEngineFactoryto handle a mime type. Overrides any such association found using the discovery mechanism.- Specified by:
registerEngineMimeTypein interfaceGremlinScriptEngineManager- Parameters:
type- The mime type to be associated with theGremlinScriptEngineFactory.factory- The class to associate with the given mime type.- Throws:
NullPointerException- if any of the parameters is null.
-
registerEngineExtension
public void registerEngineExtension(String extension, GremlinScriptEngineFactory factory)
Registers aGremlinScriptEngineFactoryto handle an extension. Overrides any such association found using the discovery mechanism.- Specified by:
registerEngineExtensionin interfaceGremlinScriptEngineManager- Parameters:
extension- The extension type to be associated with theGremlinScriptEngineFactoryfactory- The class to associate with the given extension.- Throws:
NullPointerException- if any of the parameters is null.
-
-