java.lang.Object
javax.script.ScriptEngineManager
The
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 described in the
ServiceLoader
class to enumerate all the
implementations of ScriptEngineFactory
. 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 ScriptEngine
created
by the ScriptEngineManager
. The values in the Bindings
are
generally exposed in all scripts.
- Since:
- 1.6
-
Constructor Summary
ConstructorDescriptionThe effect of calling this constructor is the same as callingScriptEngineManager(Thread.currentThread().getContextClassLoader())
.ScriptEngineManager
(ClassLoader loader) This constructor loads the implementations ofScriptEngineFactory
visible to the givenClassLoader
using the service provider mechanism.
If loader isnull
, the script engine factories that are bundled with the platform are loaded. -
Method Summary
Modifier and TypeMethodDescriptionGets the value for the specified key in the Global ScopegetBindings
returns the value of theglobalScope
field.getEngineByExtension
(String extension) Look up and create aScriptEngine
for a given extension.getEngineByMimeType
(String mimeType) Look up and create aScriptEngine
for a given mime type.getEngineByName
(String shortName) Looks up and creates aScriptEngine
for a given name.Returns a list whose elements are instances of all theScriptEngineFactory
classes found by the discovery mechanism.void
Sets the specified key/value pair in the Global Scope.void
registerEngineExtension
(String extension, ScriptEngineFactory factory) Registers aScriptEngineFactory
to handle an extension.void
registerEngineMimeType
(String type, ScriptEngineFactory factory) Registers aScriptEngineFactory
to handle a mime type.void
registerEngineName
(String name, ScriptEngineFactory factory) Registers aScriptEngineFactory
to handle a language name.void
setBindings
(Bindings bindings) setBindings
stores the specifiedBindings
in theglobalScope
field.
-
Constructor Details
-
ScriptEngineManager
public ScriptEngineManager()The effect of calling this constructor is the same as callingScriptEngineManager(Thread.currentThread().getContextClassLoader())
.- See Also:
-
ScriptEngineManager
This constructor loads the implementations ofScriptEngineFactory
visible to the givenClassLoader
using the service provider mechanism.
If loader isnull
, the script engine factories that are bundled with the platform are loaded.- Parameters:
loader
- ClassLoader used to discover script engine factories.
-
-
Method Details
-
setBindings
setBindings
stores the specifiedBindings
in theglobalScope
field. ScriptEngineManager sets thisBindings
as global bindings forScriptEngine
objects created by it.- Parameters:
bindings
- The specifiedBindings
- Throws:
IllegalArgumentException
- if bindings is null.
-
getBindings
getBindings
returns the value of theglobalScope
field. ScriptEngineManager sets thisBindings
as global bindings forScriptEngine
objects created by it.- Returns:
- The globalScope field.
-
put
Sets the specified key/value pair in the Global Scope.- Parameters:
key
- Key to setvalue
- Value to set.- Throws:
NullPointerException
- if key is null.IllegalArgumentException
- if key is empty string.
-
get
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.
-
getEngineByName
Looks up and creates aScriptEngine
for a given name. The algorithm first searches for aScriptEngineFactory
that has been registered as a handler for the specified name using theregisterEngineName
method.
If one is not found, it searches the set ofScriptEngineFactory
instances stored by the constructor for one with the specified name. If aScriptEngineFactory
is found by either method, it is used to create instance ofScriptEngine
.- Parameters:
shortName
- The short name of theScriptEngine
implementation. returned by thegetNames
method of itsScriptEngineFactory
.- Returns:
- A
ScriptEngine
created by the factory located in the search. Returns null if no such factory was found. TheScriptEngineManager
sets its ownglobalScope
Bindings
as theGLOBAL_SCOPE
Bindings
of the newly createdScriptEngine
. - Throws:
NullPointerException
- if shortName is null.
-
getEngineByExtension
Look up and create aScriptEngine
for a given extension. The algorithm used bygetEngineByName
is used except that the search starts by looking for aScriptEngineFactory
registered to handle the given extension usingregisterEngineExtension
.- 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.
-
getEngineByMimeType
Look up and create aScriptEngine
for a given mime type. The algorithm used bygetEngineByName
is used except that the search starts by looking for aScriptEngineFactory
registered to handle the given mime type usingregisterEngineMimeType
.- 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.
-
getEngineFactories
Returns a list whose elements are instances of all theScriptEngineFactory
classes found by the discovery mechanism.- Returns:
- List of all discovered
ScriptEngineFactory
s.
-
registerEngineName
Registers aScriptEngineFactory
to handle a language name. Overrides any such association found using the Discovery mechanism.- Parameters:
name
- The name to be associated with theScriptEngineFactory
.factory
- The class to associate with the given name.- Throws:
NullPointerException
- if any of the parameters is null.
-
registerEngineMimeType
Registers aScriptEngineFactory
to handle a mime type. Overrides any such association found using the Discovery mechanism.- Parameters:
type
- The mime type to be associated with theScriptEngineFactory
.factory
- The class to associate with the given mime type.- Throws:
NullPointerException
- if any of the parameters is null.
-
registerEngineExtension
Registers aScriptEngineFactory
to handle an extension. Overrides any such association found using the Discovery mechanism.- Parameters:
extension
- The extension type to be associated with theScriptEngineFactory
.factory
- The class to associate with the given extension.- Throws:
NullPointerException
- if any of the parameters is null.
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