Class AbstractScriptEngine

java.lang.Object
javax.script.AbstractScriptEngine
All Implemented Interfaces:
ScriptEngine
public abstract class AbstractScriptEngine extends Object implements ScriptEngine
Provides a standard implementation for several of the variants of the eval method.

eval(Reader)

eval(String)

eval(String, Bindings)

eval(Reader, Bindings)

are implemented using the abstract methods

eval(Reader,ScriptContext) or eval(String, ScriptContext)

with a SimpleScriptContext.

A SimpleScriptContext is used as the default ScriptContext of the AbstractScriptEngine..

Since:
1.6

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected ScriptContext
    context
    The default ScriptContext of this AbstractScriptEngine.

    Fields declared in interface ScriptEngine

    ARGV, ENGINE, ENGINE_VERSION, FILENAME, LANGUAGE, LANGUAGE_VERSION, NAME
    Modifier and Type
    Field
    Description
    static final String
    ARGV
    Reserved key for a named value that passes an array of positional arguments to a script.
    static final String
    ENGINE
    Reserved key for a named value that is the name of the ScriptEngine implementation.
    static final String
    ENGINE_VERSION
    Reserved key for a named value that identifies the version of the ScriptEngine implementation.
    static final String
    FILENAME
    Reserved key for a named value that is the name of the file being executed.
    static final String
    LANGUAGE
    Reserved key for a named value that is the full name of Scripting Language supported by the implementation.
    static final String
    LANGUAGE_VERSION
    Reserved key for the named value that identifies the version of the scripting language supported by the implementation.
    static final String
    NAME
    Reserved key for a named value that identifies the short name of the scripting language.

  • Constructor Summary

    Constructors
    Constructor
    Description
    AbstractScriptEngine()
    Creates a new instance of AbstractScriptEngine using a SimpleScriptContext as its default ScriptContext.
    AbstractScriptEngine(Bindings n)
    Creates a new instance using the specified Bindings as the ENGINE_SCOPE Bindings in the protected context field.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    eval(Reader reader)
    eval(Reader) calls the abstract eval(Reader, ScriptContext) passing the value of the context field.
    Object
    eval(Reader reader, Bindings bindings)
    eval(Reader, Bindings) calls the abstract eval(Reader, ScriptContext) method, passing it a ScriptContext whose Reader, Writers and Bindings for scopes other that ENGINE_SCOPE are identical to those members of the protected context field.
    Object
    eval(String script)
    Same as eval(Reader) except that the abstract eval(String, ScriptContext) is used.
    Object
    eval(String script, Bindings bindings)
    Same as eval(Reader, Bindings) except that the abstract eval(String, ScriptContext) is used.
    Object
    get(String key)
    Gets the value for the specified key in the ENGINE_SCOPE of the protected context field.
    Bindings
    getBindings(int scope)
    Returns the Bindings with the specified scope value in the protected context field.
    ScriptContext
    getContext()
    Returns the value of the protected context field.
    protected ScriptContext
    getScriptContext(Bindings nn)
    Returns a SimpleScriptContext.
    void
    put(String key, Object value)
    Sets the specified value with the specified key in the ENGINE_SCOPE Bindings of the protected context field.
    void
    setBindings(Bindings bindings, int scope)
    Sets the Bindings with the corresponding scope value in the context field.
    void
    setContext(ScriptContext ctxt)
    Sets the value of the protected context field to the specified ScriptContext.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Creates and returns a copy of this object.
    boolean
    equals(Object obj)
    Indicates whether some other object is "equal to" this one.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    int
    hashCode()
    Returns a hash code value for this object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

    Methods declared in interface ScriptEngine

    createBindings, eval, eval, getFactory
    Modifier and Type
    Method
    Description
    Bindings
    createBindings()
    Returns an uninitialized Bindings.
    Object
    eval(Reader reader, ScriptContext context)
    Same as eval(String, ScriptContext) where the source of the script is read from a Reader.
    Object
    eval(String script, ScriptContext context)
    Causes the immediate execution of the script whose source is the String passed as the first argument.
    ScriptEngineFactory
    getFactory()
    Returns a ScriptEngineFactory for the class to which this ScriptEngine belongs.

  • Field Details

    • context

      protected ScriptContext context
      The default ScriptContext of this AbstractScriptEngine.

  • Constructor Details

    • AbstractScriptEngine

      public AbstractScriptEngine()
      Creates a new instance of AbstractScriptEngine using a SimpleScriptContext as its default ScriptContext.

    • AbstractScriptEngine

      public AbstractScriptEngine(Bindings n)
      Creates a new instance using the specified Bindings as the ENGINE_SCOPE Bindings in the protected context field.
      Parameters:
      n - The specified Bindings.
      Throws:
      NullPointerException - if n is null.

  • Method Details

    • setContext

      public void setContext(ScriptContext ctxt)
      Sets the value of the protected context field to the specified ScriptContext.
      Specified by:
      setContext in interface ScriptEngine
      Parameters:
      ctxt - The specified ScriptContext.
      Throws:
      NullPointerException - if ctxt is null.

    • getContext

      public ScriptContext getContext()
      Returns the value of the protected context field.
      Specified by:
      getContext in interface ScriptEngine
      Returns:
      The value of the protected context field.

    • getBindings

      public Bindings getBindings(int scope)
      Returns the Bindings with the specified scope value in the protected context field.
      Specified by:
      getBindings in interface ScriptEngine
      Parameters:
      scope - The specified scope
      Returns:
      The corresponding Bindings.
      Throws:
      IllegalArgumentException - if the value of scope is invalid for the type the protected context field.

    • setBindings

      public void setBindings(Bindings bindings, int scope)
      Sets the Bindings with the corresponding scope value in the context field.
      Specified by:
      setBindings in interface ScriptEngine
      Parameters:
      bindings - The specified Bindings.
      scope - The specified scope.
      Throws:
      IllegalArgumentException - if the value of scope is invalid for the type the context field.
      NullPointerException - if the bindings is null and the scope is ScriptContext.ENGINE_SCOPE

    • put

      public void put(String key, Object value)
      Sets the specified value with the specified key in the ENGINE_SCOPE Bindings of the protected context field.
      Specified by:
      put in interface ScriptEngine
      Parameters:
      key - The specified key.
      value - The specified value.
      Throws:
      NullPointerException - if key is null.
      IllegalArgumentException - if key is empty.

    • get

      public Object get(String key)
      Gets the value for the specified key in the ENGINE_SCOPE of the protected context field.
      Specified by:
      get in interface ScriptEngine
      Parameters:
      key - The key whose value is to be returned
      Returns:
      The value for the specified key.
      Throws:
      NullPointerException - if key is null.
      IllegalArgumentException - if key is empty.

    • eval

      public Object eval(Reader reader, Bindings bindings) throws ScriptException
      eval(Reader, Bindings) calls the abstract eval(Reader, ScriptContext) method, passing it a ScriptContext whose Reader, Writers and Bindings for scopes other that ENGINE_SCOPE are identical to those members of the protected context field. The specified Bindings is used instead of the ENGINE_SCOPE Bindings of the context field.
      Specified by:
      eval in interface ScriptEngine
      Parameters:
      reader - A Reader containing the source of the script.
      bindings - A Bindings to use for the ENGINE_SCOPE while the script executes.
      Returns:
      The return value from eval(Reader, ScriptContext)
      Throws:
      ScriptException - if an error occurs in script.
      NullPointerException - if any of the parameters is null.

    • eval

      public Object eval(String script, Bindings bindings) throws ScriptException
      Same as eval(Reader, Bindings) except that the abstract eval(String, ScriptContext) is used.
      Specified by:
      eval in interface ScriptEngine
      Parameters:
      script - A String containing the source of the script.
      bindings - A Bindings to use as the ENGINE_SCOPE while the script executes.
      Returns:
      The return value from eval(String, ScriptContext)
      Throws:
      ScriptException - if an error occurs in script.
      NullPointerException - if any of the parameters is null.

    • eval

      public Object eval(Reader reader) throws ScriptException
      eval(Reader) calls the abstract eval(Reader, ScriptContext) passing the value of the context field.
      Specified by:
      eval in interface ScriptEngine
      Parameters:
      reader - A Reader containing the source of the script.
      Returns:
      The return value from eval(Reader, ScriptContext)
      Throws:
      ScriptException - if an error occurs in script.
      NullPointerException - if any of the parameters is null.

    • eval

      public Object eval(String script) throws ScriptException
      Same as eval(Reader) except that the abstract eval(String, ScriptContext) is used.
      Specified by:
      eval in interface ScriptEngine
      Parameters:
      script - A String containing the source of the script.
      Returns:
      The return value from eval(String, ScriptContext)
      Throws:
      ScriptException - if an error occurs in script.
      NullPointerException - if any of the parameters is null.

    • getScriptContext

      protected ScriptContext getScriptContext(Bindings nn)
      Returns a SimpleScriptContext. The SimpleScriptContext:

      • Uses the specified Bindings for its ENGINE_SCOPE
      • Uses the Bindings returned by the abstract getGlobalScope method as its GLOBAL_SCOPE
      • Uses the Reader and Writer in the default ScriptContext of this ScriptEngine


      A SimpleScriptContext returned by this method is used to implement eval methods using the abstract eval(Reader,Bindings) and eval(String,Bindings) versions.
      Parameters:
      nn - Bindings to use for the ENGINE_SCOPE
      Returns:
      The SimpleScriptContext