public class

ScriptEngineManager

extends Object
java.lang.Object
   ↳ javax.script.ScriptEngineManager

Class Overview

The ScriptEngineManager implements a discovery and instantiation mechanism for ScriptEngine classes and also maintains a collection of key/value pairs storing state shared by all engines created by the Manager. This class uses the service provider mechanism to enumerate all the implementations of ScriptEngineFactory.

The ScriptEngineManager provides a method to return an array 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 ScriptEngine created by the ScriptEngineManager. The values in the Bindings are generally exposed in all scripts.

Summary

Public Constructors
ScriptEngineManager()
If the thread context ClassLoader can be accessed by the caller, then the effect of calling this constructor is the same as calling ScriptEngineManager(Thread.currentThread().getContextClassLoader()).
ScriptEngineManager(ClassLoader loader)
This constructor loads the implementations of ScriptEngineFactory visible to the given ClassLoader using the service provider mechanism.
Public Methods
Object get(String key)
Gets the value for the specified key in the Global Scope
Bindings getBindings()
getBindings returns the value of the globalScope field.
ScriptEngine getEngineByExtension(String extension)
Look up and create a ScriptEngine for a given extension.
ScriptEngine getEngineByMimeType(String mimeType)
Look up and create a ScriptEngine for a given mime type.
ScriptEngine getEngineByName(String shortName)
Looks up and creates a ScriptEngine for a given name.
List<ScriptEngineFactory> getEngineFactories()
Returns an array whose elements are instances of all the ScriptEngineFactory 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, ScriptEngineFactory factory)
Registers a ScriptEngineFactory to handle an extension.
void registerEngineMimeType(String type, ScriptEngineFactory factory)
Registers a ScriptEngineFactory to handle a mime type.
void registerEngineName(String name, ScriptEngineFactory factory)
Registers a ScriptEngineFactory to handle a language name.
void setBindings(Bindings bindings)
setBindings stores the specified Bindings in the globalScope field.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public ScriptEngineManager ()

If the thread context ClassLoader can be accessed by the caller, then the effect of calling this constructor is the same as calling ScriptEngineManager(Thread.currentThread().getContextClassLoader()). Otherwise, the effect is the same as calling ScriptEngineManager(null).

See Also

public ScriptEngineManager (ClassLoader loader)

This constructor loads the implementations of ScriptEngineFactory visible to the given ClassLoader using the service provider 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.

Parameters
loader ClassLoader used to discover script engine factories.

Public Methods

public Object get (String key)

Gets the value for the specified key in the Global Scope

Parameters
key The key whose value is to be returned.
Returns
  • The value for the specified key.

public Bindings getBindings ()

getBindings returns the value of the globalScope field. ScriptEngineManager sets this Bindings as global bindings for ScriptEngine objects created by it.

Returns
  • The globalScope field.

public ScriptEngine getEngineByExtension (String extension)

Look up and create a ScriptEngine for a given extension. The algorithm used by getEngineByName is used except that the search starts by looking for a ScriptEngineFactory registered to handle the given extension using registerEngineExtension.

Parameters
extension The given extension
Returns
  • The engine to handle scripts with this extension. Returns null if not found.
Throws
NullPointerException if extension is null.

public ScriptEngine getEngineByMimeType (String mimeType)

Look up and create a ScriptEngine for a given mime type. The algorithm used by getEngineByName is used except that the search starts by looking for a ScriptEngineFactory registered to handle the given mime type using registerEngineMimeType.

Parameters
mimeType The given mime type
Returns
  • The engine to handle scripts with this mime type. Returns null if not found.
Throws
NullPointerException if mimeType is null.

public ScriptEngine getEngineByName (String shortName)

Looks up and creates a ScriptEngine for a given name. The algorithm first searches for a ScriptEngineFactory that has been registered as a handler for the specified name using the registerEngineName method.

If one is not found, it searches the array of ScriptEngineFactory 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 ScriptEngine.

Parameters
shortName The short name of the ScriptEngine implementation. returned by the getNames method of its ScriptEngineFactory.
Returns
  • A ScriptEngine created by the factory located in the search. Returns null if no such factory was found. The ScriptEngineManager sets its own globalScope Bindings as the GLOBAL_SCOPE Bindings of the newly created ScriptEngine.
Throws
NullPointerException if shortName is null.

public List<ScriptEngineFactory> getEngineFactories ()

Returns an array whose elements are instances of all the ScriptEngineFactory classes found by the discovery mechanism.

Returns
  • List of all discovered ScriptEngineFactorys.

public void put (String key, Object value)

Sets the specified key/value pair in the Global Scope.

Parameters
key Key to set
value Value to set.
Throws
NullPointerException if key is null.
IllegalArgumentException if key is empty string.

public void registerEngineExtension (String extension, ScriptEngineFactory factory)

Registers a ScriptEngineFactory to handle an extension. Overrides any such association found using the Discovery mechanism.

Parameters
extension The extension type to be associated with the ScriptEngineFactory.
factory The class to associate with the given extension.
Throws
NullPointerException if any of the parameters is null.

public void registerEngineMimeType (String type, ScriptEngineFactory factory)

Registers a ScriptEngineFactory to handle a mime type. Overrides any such association found using the Discovery mechanism.

Parameters
type The mime type to be associated with the ScriptEngineFactory.
factory The class to associate with the given mime type.
Throws
NullPointerException if any of the parameters is null.

public void registerEngineName (String name, ScriptEngineFactory factory)

Registers a ScriptEngineFactory to handle a language name. Overrides any such association found using the Discovery mechanism.

Parameters
name The name to be associated with the ScriptEngineFactory.
factory The class to associate with the given name.
Throws
NullPointerException if any of the parameters is null.

public void setBindings (Bindings bindings)

setBindings stores the specified Bindings in the globalScope field. ScriptEngineManager sets this Bindings as global bindings for ScriptEngine objects created by it.

Parameters
bindings The specified Bindings
Throws
IllegalArgumentException if bindings is null.