ScriptEngineManager (Java SE 15 & JDK 15) (original) (raw)

public class ScriptEngineManager extends Object

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 theServiceLoader 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

Constructors

• Method Summary

Methods declared in class java.lang.Object

[clone](../../../java.base/java/lang/Object.html#clone%28%29), [equals](../../../java.base/java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../../java.base/java/lang/Object.html#finalize%28%29), [getClass](../../../java.base/java/lang/Object.html#getClass%28%29), [hashCode](../../../java.base/java/lang/Object.html#hashCode%28%29), [notify](../../../java.base/java/lang/Object.html#notify%28%29), [notifyAll](../../../java.base/java/lang/Object.html#notifyAll%28%29), [toString](../../../java.base/java/lang/Object.html#toString%28%29), [wait](../../../java.base/java/lang/Object.html#wait%28%29), [wait](../../../java.base/java/lang/Object.html#wait%28long%29), [wait](../../../java.base/java/lang/Object.html#wait%28long,int%29)

• Constructor Details

  • ScriptEngineManager

  public ScriptEngineManager()
  The effect of calling this constructor is the same as callingScriptEngineManager(Thread.currentThread().getContextClassLoader()).
  See Also:
  Thread.getContextClassLoader()

  • ScriptEngineManager

  public ScriptEngineManager​(ClassLoader loader)
  This constructor loads the implementations ofScriptEngineFactory visible to the givenClassLoader using the service provider mechanism.
  If loader is null, the script engine factories that are bundled with the platform are loaded.
  Parameters:
  loader - ClassLoader used to discover script engine factories.

• Method Details

  • setBindings

  public void setBindings​(Bindings bindings)
  setBindings stores the specified Bindings in the globalScope field. ScriptEngineManager sets thisBindings as global bindings for ScriptEngine objects created by it.
  Parameters:
  bindings - The specified Bindings
  Throws:
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if bindings is null.

  • getBindings

  getBindings returns the value of the globalScope field. ScriptEngineManager sets this Bindings 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 set
  value - Value to set.
  Throws:
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if key is null.
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - 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 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 set 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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if shortName is null.

  • getEngineByExtension

  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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if extension is null.

  • getEngineByMimeType

  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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if mimeType is null.

  • getEngineFactories

  Returns a list whose elements are instances of all the ScriptEngineFactory classes found by the discovery mechanism.
  Returns:
  List of all discovered ScriptEngineFactorys.

  • registerEngineName

  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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if any of the parameters is null.

  • registerEngineMimeType

  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 theScriptEngineFactory.
  factory - The class to associate with the given mime type.
  Throws:
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if any of the parameters is null.

  • registerEngineExtension

  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 theScriptEngineFactory.
  factory - The class to associate with the given extension.
  Throws:
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if any of the parameters is null.