public interface

ScriptContext

javax.script.ScriptContext
Known Indirect Subclasses

Class Overview

The interface whose implementing classes are used to connect Script Engines with objects, such as scoped Bindings, in hosting applications. Each scope is a set of named attributes whose values can be set and retrieved using the ScriptContext methods. ScriptContexts also expose Readers and Writers that can be used by the ScriptEngines for input and output.

Summary

Constants
int ENGINE_SCOPE EngineScope attributes are visible during the lifetime of a single ScriptEngine and a set of attributes is maintained for each engine.
int GLOBAL_SCOPE GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.
Public Methods
abstract Object getAttribute(String name)
Retrieves the value of the attribute with the given name in the scope occurring earliest in the search order.
abstract Object getAttribute(String name, int scope)
Gets the value of an attribute in a given scope.
abstract int getAttributesScope(String name)
Get the lowest scope in which an attribute is defined.
abstract Bindings getBindings(int scope)
Gets the Bindings associated with the given scope in this ScriptContext.
abstract Writer getErrorWriter()
Returns the Writer used to display error output.
abstract Reader getReader()
Returns a Reader to be used by the script to read input.
abstract List<Integer> getScopes()
Returns immutable List of all the valid values for scope in the ScriptContext.
abstract Writer getWriter()
Returns the Writer for scripts to use when displaying output.
abstract Object removeAttribute(String name, int scope)
Remove an attribute in a given scope.
abstract void setAttribute(String name, Object value, int scope)
Sets the value of an attribute in a given scope.
abstract void setBindings(Bindings bindings, int scope)
Associates a Bindings instance with a particular scope in this ScriptContext.
abstract void setErrorWriter(Writer writer)
Sets the Writer used to display error output.
abstract void setReader(Reader reader)
Sets the Reader for scripts to read input .
abstract void setWriter(Writer writer)
Sets the Writer for scripts to use when displaying output.

Constants

public 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.

Constant Value: 100 (0x00000064)

public static final int GLOBAL_SCOPE

GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.

Constant Value: 200 (0x000000c8)

Public Methods

public abstract 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.)

Parameters
name The name of the 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.

public abstract Object getAttribute (String name, int scope)

Gets the value of an attribute in a given scope.

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.

public abstract int getAttributesScope (String name)

Get the lowest scope in which an attribute is defined.

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.

public abstract Bindings getBindings (int scope)

Gets the Bindings associated with the given scope in this ScriptContext.

Returns
  • The associated Bindings. Returns null if it has not been set.
Throws
IllegalArgumentException If no Bindings is defined for the specified scope value in ScriptContext of this type.

public abstract Writer getErrorWriter ()

Returns the Writer used to display error output.

Returns
  • The Writer

public abstract Reader getReader ()

Returns a Reader to be used by the script to read input.

Returns
  • The Reader.

public abstract List<Integer> getScopes ()

Returns immutable List of all the valid values for scope in the ScriptContext.

Returns
  • list of scope values

public abstract Writer getWriter ()

Returns the Writer for scripts to use when displaying output.

Returns
  • The Writer.

public abstract Object removeAttribute (String name, int scope)

Remove an attribute in a given scope.

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.

public abstract void setAttribute (String name, Object value, int scope)

Sets the value of an attribute in a given scope.

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.

public abstract void setBindings (Bindings bindings, int scope)

Associates a Bindings instance with a particular scope in this ScriptContext. Calls to the getAttribute and setAttribute methods must map to the get and put methods of the Bindings for the specified scope.

Parameters
bindings The Bindings to associate with the given scope
scope The scope
Throws
IllegalArgumentException If no Bindings is defined for the specified scope value in ScriptContexts of this type.
NullPointerException if value of scope is ENGINE_SCOPE and the specified Bindings is null.

public abstract void setErrorWriter (Writer writer)

Sets the Writer used to display error output.

Parameters
writer The Writer.

public abstract void setReader (Reader reader)

Sets the Reader for scripts to read input .

Parameters
reader The new Reader.

public abstract void setWriter (Writer writer)

Sets the Writer for scripts to use when displaying output.

Parameters
writer The new Writer.