Class SimpleScriptContext

java.lang.Object
javax.script.SimpleScriptContext
All Implemented Interfaces:
ScriptContext
public class SimpleScriptContext extends Object implements ScriptContext
Simple implementation of ScriptContext.
Since:
1.6

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected Bindings
    engineScope
    This is the engine scope bindings.
    protected Writer
    errorWriter
    This is the writer to be used to output errors from scripts.
    protected Bindings
    globalScope
    This is the global scope bindings.
    protected Reader
    reader
    This is the reader to be used for input from scripts.
    protected Writer
    writer
    This is the writer to be used to output from scripts.

    Fields declared in interface ScriptContext

    ENGINE_SCOPE, GLOBAL_SCOPE
    Modifier and Type
    Field
    Description
    static final int
    ENGINE_SCOPE
    EngineScope attributes are visible during the lifetime of a single ScriptEngine and a set of attributes is maintained for each engine.
    static final int
    GLOBAL_SCOPE
    GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.

  • Constructor Summary

    Constructors
    Constructor
    Description
    SimpleScriptContext()
    Create a SimpleScriptContext.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    getAttribute(String name)
    Retrieves the value of the attribute with the given name in the scope occurring earliest in the search order.
    Object
    getAttribute(String name, int scope)
    Gets the value of an attribute in a given scope.
    int
    getAttributesScope(String name)
    Get the lowest scope in which an attribute is defined.
    Bindings
    getBindings(int scope)
    Returns the value of the engineScope field if specified scope is ENGINE_SCOPE.
    Writer
    getErrorWriter()
    Returns the Writer used to display error output.
    Reader
    getReader()
    Returns a Reader to be used by the script to read input.
    List<Integer>
    getScopes()
    Returns immutable List of all the valid values for scope in the ScriptContext.
    Writer
    getWriter()
    Returns the Writer for scripts to use when displaying output.
    Object
    removeAttribute(String name, int scope)
    Remove an attribute in a given scope.
    void
    setAttribute(String name, Object value, int scope)
    Sets the value of an attribute in a given scope.
    void
    setBindings(Bindings bindings, int scope)
    Sets a Bindings of attributes for the given scope.
    void
    setErrorWriter(Writer writer)
    Sets the Writer used to display error output.
    void
    setReader(Reader reader)
    Sets the Reader for scripts to read input .
    void
    setWriter(Writer writer)
    Sets the Writer for scripts to use when displaying output.

    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.

  • Field Details

    • writer

      protected Writer writer
      This is the writer to be used to output from scripts. By default, a PrintWriter based on System.out is used. Accessor methods getWriter, setWriter are used to manage this field.
      See Also:

    • errorWriter

      protected Writer errorWriter
      This is the writer to be used to output errors from scripts. By default, a PrintWriter based on System.err is used. Accessor methods getErrorWriter, setErrorWriter are used to manage this field.
      See Also:

    • reader

      protected Reader reader
      This is the reader to be used for input from scripts. By default, a InputStreamReader based on System.in is used and default charset is used by this reader. Accessor methods getReader, setReader are used to manage this field.
      See Also:

    • engineScope

      protected Bindings engineScope
      This is the engine scope bindings. By default, a SimpleBindings is used. Accessor methods setBindings, getBindings are used to manage this field.
      See Also:

    • globalScope

      protected Bindings globalScope
      This is the global scope bindings. By default, a null value (which means no global scope) is used. Accessor methods setBindings, getBindings are used to manage this field.

  • Constructor Details

    • SimpleScriptContext

      public SimpleScriptContext()
      Create a SimpleScriptContext.

  • Method Details

    • setBindings

      public void setBindings(Bindings bindings, int scope)
      Sets a Bindings of attributes for the given scope. If the value of scope is ENGINE_SCOPE the given Bindings replaces the engineScope field. If the value of scope is GLOBAL_SCOPE the given Bindings replaces the globalScope field.
      Specified by:
      setBindings in interface ScriptContext
      Parameters:
      bindings - The Bindings of attributes to set.
      scope - The value of the scope in which the attributes are set.
      Throws:
      IllegalArgumentException - if scope is invalid.
      NullPointerException - if the value of scope is ENGINE_SCOPE and the specified Bindings is null.

    • getAttribute

      public Object getAttribute(String name)
      Retrieves the value of the attribute with the given name in the scope occurring earliest in the search order. The order is determined by the numeric value of the scope parameter (lowest scope values first.)
      Specified by:
      getAttribute in interface ScriptContext
      Parameters:
      name - The name of the attribute to retrieve.
      Returns:
      The value of the attribute in the lowest scope for which an attribute with the given name is defined. Returns null if no attribute with the name exists in any scope.
      Throws:
      NullPointerException - if the name is null.
      IllegalArgumentException - if the name is empty.

    • getAttribute

      public Object getAttribute(String name, int scope)
      Gets the value of an attribute in a given scope.
      Specified by:
      getAttribute in interface ScriptContext
      Parameters:
      name - The name of the attribute to retrieve.
      scope - The scope in which to retrieve the attribute.
      Returns:
      The value of the attribute. Returns null is the name does not exist in the given scope.
      Throws:
      IllegalArgumentException - if the name is empty or if the value of scope is invalid.
      NullPointerException - if the name is null.

    • removeAttribute

      public Object removeAttribute(String name, int scope)
      Remove an attribute in a given scope.
      Specified by:
      removeAttribute in interface ScriptContext
      Parameters:
      name - The name of the attribute to remove
      scope - The scope in which to remove the attribute
      Returns:
      The removed value.
      Throws:
      IllegalArgumentException - if the name is empty or if the scope is invalid.
      NullPointerException - if the name is null.

    • setAttribute

      public void setAttribute(String name, Object value, int scope)
      Sets the value of an attribute in a given scope. If the scope is GLOBAL_SCOPE and no Bindings is set for GLOBAL_SCOPE, then setAttribute call is a no-op.
      Specified by:
      setAttribute in interface ScriptContext
      Parameters:
      name - The name of the attribute to set
      value - The value of the attribute
      scope - The scope in which to set the attribute
      Throws:
      IllegalArgumentException - if the name is empty or if the scope is invalid.
      NullPointerException - if the name is null.

    • getWriter

      public Writer getWriter()
      Returns the Writer for scripts to use when displaying output.
      Specified by:
      getWriter in interface ScriptContext
      Returns:
      The Writer.

    • getReader

      public Reader getReader()
      Returns a Reader to be used by the script to read input.
      Specified by:
      getReader in interface ScriptContext
      Returns:
      The Reader.

    • setReader

      public void setReader(Reader reader)
      Sets the Reader for scripts to read input .
      Specified by:
      setReader in interface ScriptContext
      Parameters:
      reader - The new Reader.

    • setWriter

      public void setWriter(Writer writer)
      Sets the Writer for scripts to use when displaying output.
      Specified by:
      setWriter in interface ScriptContext
      Parameters:
      writer - The new Writer.

    • getErrorWriter

      public Writer getErrorWriter()
      Returns the Writer used to display error output.
      Specified by:
      getErrorWriter in interface ScriptContext
      Returns:
      The Writer

    • setErrorWriter

      public void setErrorWriter(Writer writer)
      Sets the Writer used to display error output.
      Specified by:
      setErrorWriter in interface ScriptContext
      Parameters:
      writer - The Writer.

    • getAttributesScope

      public int getAttributesScope(String name)
      Get the lowest scope in which an attribute is defined.
      Specified by:
      getAttributesScope in interface ScriptContext
      Parameters:
      name - Name of the attribute .
      Returns:
      The lowest scope. Returns -1 if no attribute with the given name is defined in any scope.
      Throws:
      NullPointerException - if name is null.
      IllegalArgumentException - if name is empty.

    • getBindings

      public Bindings getBindings(int scope)
      Returns the value of the engineScope field if specified scope is ENGINE_SCOPE. Returns the value of the globalScope field if the specified scope is GLOBAL_SCOPE.
      Specified by:
      getBindings in interface ScriptContext
      Parameters:
      scope - The specified scope
      Returns:
      The value of either the engineScope or globalScope field.
      Throws:
      IllegalArgumentException - if the value of scope is invalid.

    • getScopes

      public List<Integer> getScopes()
      Returns immutable List of all the valid values for scope in the ScriptContext.
      Specified by:
      getScopes in interface ScriptContext
      Returns:
      list of scope values