DefaultGremlinScriptEngineManager (Apache TinkerPop 3.4.5 API)

java.lang.Object
- org.apache.tinkerpop.gremlin.jsr223.DefaultGremlinScriptEngineManager

All Implemented Interfaces:

GremlinScriptEngineManager

Direct Known Subclasses:

CachedGremlinScriptEngineManager
```
public class DefaultGremlinScriptEngineManager
extends Object
implements GremlinScriptEngineManager
```
The ScriptEngineManager implements a discovery, instantiation and configuration mechanism for GremlinScriptEngine classes and also maintains a collection of key/value pairs storing state shared by all engines created by it. This class uses the ServiceProvider mechanism to enumerate all the implementations of GremlinScriptEngineFactory. The ScriptEngineManager provides 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.
The Bindings of key/value pairs, referred to as the "Global Scope" maintained by the manager is available to all instances of @code ScriptEngine} created by the GremlinScriptEngineManager. The values in the Bindings are generally exposed in all scripts.
This class is based quite heavily on the workings of the ScriptEngineManager supplied in the javax.script packages, but adds some additional features that are specific to Gremlin and TinkerPop. Unfortunately, it's not easily possible to extend ScriptEngineManager directly 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" ScriptEngine instances (i.e. those that extend from GremlinScriptEngine) and is not meant to manage just any ScriptEngine instance that may be on the path.
As this is a "Gremlin" ScriptEngine, certain common imports are automatically applied when a GremlinScriptEngine is instantiated via the GremlinScriptEngineFactory.. Initial imports from gremlin-core come from the CoreImports.

Author:

Stephen Mallette (http://stephen.genoprime.com)

Constructor Summary

Constructors
Constructor and Description
`DefaultGremlinScriptEngineManager()` The effect of calling this constructor is the same as calling `DefaultGremlinScriptEngineManager(Thread.currentThread().getContextClassLoader())`.
`DefaultGremlinScriptEngineManager(ClassLoader loader)` This constructor loads the implementations of `GremlinScriptEngineFactory` visible to the given `ClassLoader` using the `ServiceLoader` mechanism.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addPlugin(GremlinPlugin plugin)` Add `GremlinPlugin` instances to customize newly created `GremlinScriptEngine` instances.
`Object`	`get(String key)` Gets the value for the specified key in the global scope.
`Bindings`	`getBindings()` Gets the bindings of the `Bindings` in global scope.
`List<Customizer>`	`getCustomizers(String scriptEngineName)` Get the list of `Customizer` instances filtered by the `scriptEngineName`.
`GremlinScriptEngine`	`getEngineByExtension(String extension)` Look up and create a `GremlinScriptEngine` for a given extension.
`GremlinScriptEngine`	`getEngineByMimeType(String mimeType)` Look up and create a `GremlinScriptEngine` for a given mime type.
`GremlinScriptEngine`	`getEngineByName(String shortName)` Looks up and creates a `GremlinScriptEngine` for a given name.
`List<GremlinScriptEngineFactory>`	`getEngineFactories()` Returns a list whose elements are instances of all the `GremlinScriptEngineFactory` classes found by the discovery mechanism.
`void`	`put(String key, Object value)` Sets the specified key/value pair in the global scope.
`void`	`registerEngineExtension(String extension, GremlinScriptEngineFactory factory)` Registers a `GremlinScriptEngineFactory` to handle an extension.
`void`	`registerEngineMimeType(String type, GremlinScriptEngineFactory factory)` Registers a `GremlinScriptEngineFactory` to handle a mime type.
`void`	`registerEngineName(String name, GremlinScriptEngineFactory factory)` Registers a `GremlinScriptEngineFactory` to handle a language name.
`void`	`setBindings(Bindings bindings)` Stores the specified `Bindings` as a global for all `GremlinScriptEngine` objects created by it.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DefaultGremlinScriptEngineManager
```
public DefaultGremlinScriptEngineManager()
```
    The effect of calling this constructor is the same as calling DefaultGremlinScriptEngineManager(Thread.currentThread().getContextClassLoader()).
  - DefaultGremlinScriptEngineManager
```
public DefaultGremlinScriptEngineManager(ClassLoader loader)
```
    This constructor loads the implementations of GremlinScriptEngineFactory visible to the given ClassLoader using the ServiceLoader mechanism. If loader is null, 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: GremlinScriptEngineManager
    
    Get the list of Customizer instances filtered by the scriptEngineName.
    
    Specified by:
    
    getCustomizers in interface GremlinScriptEngineManager
  - addPlugin
```
public void addPlugin(GremlinPlugin plugin)
```
    Description copied from interface: GremlinScriptEngineManager
    
    Add GremlinPlugin instances to customize newly created GremlinScriptEngine instances.
    
    Specified by:
    
    addPlugin in interface GremlinScriptEngineManager
  - setBindings
```
public void setBindings(Bindings bindings)
```
    Stores the specified Bindings as a global for all GremlinScriptEngine objects created by it. If the bindings are to be updated by multiple threads it is recommended that a ConcurrentBindings instance is supplied.
    
    Specified by:
    
    setBindings in interface GremlinScriptEngineManager
    
    Throws:
    
    IllegalArgumentException - if bindings is null.
  - getBindings
```
public Bindings getBindings()
```
    Gets the bindings of the Bindings in global scope.
    
    Specified by:
    
    getBindings in interface GremlinScriptEngineManager
  - 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:
    
    put in interface GremlinScriptEngineManager
    
    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:
    
    get in interface GremlinScriptEngineManager
  - getEngineByName
```
public GremlinScriptEngine getEngineByName(String shortName)
```
    Looks up and creates a GremlinScriptEngine for a given name. The algorithm first searches for a GremlinScriptEngineFactory that has been registered as a handler for the specified name using the registerEngineExtension(String, GremlinScriptEngineFactory) method. If one is not found, it searches the set of GremlinScriptEngineFactory instances stored by the constructor for one with the specified name. If a ScriptEngineFactory is found by either method, it is used to create instance of GremlinScriptEngine.
    
    Specified by:
    
    getEngineByName in interface GremlinScriptEngineManager
    
    Parameters:
    
    shortName - The short name of the GremlinScriptEngine implementation returned by the ScriptEngineFactory.getNames() method.
    
    Returns:
    
    A GremlinScriptEngine created by the factory located in the search. Returns null if no such factory was found. The global scope of this manager is applied to the newly created GremlinScriptEngine
    
    Throws:
    
    NullPointerException - if shortName is null.
  - getEngineByExtension
```
public GremlinScriptEngine getEngineByExtension(String extension)
```
    Look up and create a GremlinScriptEngine for a given extension. The algorithm used by getEngineByName(String) is used except that the search starts by looking for a GremlinScriptEngineFactory registered to handle the given extension using registerEngineExtension(String, GremlinScriptEngineFactory).
    
    Specified by:
    
    getEngineByExtension in interface GremlinScriptEngineManager
    
    Returns:
    
    The engine to handle scripts with this extension. Returns null if not found.
    
    Throws:
    
    NullPointerException - if extension is null.
  - getEngineByMimeType
```
public GremlinScriptEngine getEngineByMimeType(String mimeType)
```
    Look up and create a GremlinScriptEngine for a given mime type. The algorithm used by getEngineByName(String) is used except that the search starts by looking for a GremlinScriptEngineFactory registered to handle the given mime type using registerEngineMimeType(String, GremlinScriptEngineFactory).
    
    Specified by:
    
    getEngineByMimeType in interface GremlinScriptEngineManager
    
    Parameters:
    
    mimeType - The given mime type
    
    Returns:
    
    The engine to handle scripts with this mime type. Returns null if not found.
    
    Throws:
    
    NullPointerException - if mime-type is null.
  - getEngineFactories
```
public List<GremlinScriptEngineFactory> getEngineFactories()
```
    Returns a list whose elements are instances of all the GremlinScriptEngineFactory classes found by the discovery mechanism.
    
    Specified by:
    
    getEngineFactories in interface GremlinScriptEngineManager
    
    Returns:
    
    List of all discovered GremlinScriptEngineFactory objects.
  - registerEngineName
```
public void registerEngineName(String name,
                               GremlinScriptEngineFactory factory)
```
    Registers a GremlinScriptEngineFactory to handle a language name. Overrides any such association found using the discovery mechanism.
    
    Specified by:
    
    registerEngineName in interface GremlinScriptEngineManager
    
    Parameters:
    
    name - The name to be associated with the GremlinScriptEngineFactory
    
    factory - 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 a GremlinScriptEngineFactory to handle a mime type. Overrides any such association found using the discovery mechanism.
    
    Specified by:
    
    registerEngineMimeType in interface GremlinScriptEngineManager
    
    Parameters:
    
    type - The mime type to be associated with the GremlinScriptEngineFactory.
    
    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 a GremlinScriptEngineFactory to handle an extension. Overrides any such association found using the discovery mechanism.
    
    Specified by:
    
    registerEngineExtension in interface GremlinScriptEngineManager
    
    Parameters:
    
    extension - The extension type to be associated with the GremlinScriptEngineFactory
    
    factory - The class to associate with the given extension.
    
    Throws:
    
    NullPointerException - if any of the parameters is null.

Class DefaultGremlinScriptEngineManager

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DefaultGremlinScriptEngineManager

DefaultGremlinScriptEngineManager

Method Detail

getCustomizers

addPlugin

setBindings

getBindings

put

get

getEngineByName

getEngineByExtension

getEngineByMimeType

getEngineFactories

registerEngineName

registerEngineMimeType

registerEngineExtension