Class ScriptEngineManager

java.lang.Object
javax.script.ScriptEngineManager
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 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

    Constructors
    Constructor
    Description
    ScriptEngineManager()
    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.

    If loader is null, the script engine factories that are bundled with the platform are loaded.

  • Method Summary

    Modifier and Type
    Method
    Description
    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 a list 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.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • ScriptEngineManager

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

    • ScriptEngineManager

      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 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 this Bindings as global bindings for ScriptEngine objects created by it.
      Parameters:
      bindings - The specified Bindings
      Throws:
      IllegalArgumentException - if bindings is null.

    • getBindings

      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.

    • put

      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.

    • get

      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.

    • getEngineByName

      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 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 - if shortName is null.

    • getEngineByExtension

      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.

    • getEngineByMimeType

      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.

    • getEngineFactories

      public List<ScriptEngineFactory> 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

      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.

    • registerEngineMimeType

      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.

    • registerEngineExtension

      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.