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

All Known Implementing Classes:

[SimpleScriptContext](SimpleScriptContext.html "class in javax.script")

public interface ScriptContext

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 theScriptContext methods. ScriptContexts also expose Readers and Writers that can be used by the ScriptEngines for input and output.

Since:

1.6

• Field Summary

Fields

• Method Summary

• Field Details

  • ENGINE_SCOPE

  static final int ENGINE_SCOPE
  EngineScope attributes are visible during the lifetime of a singleScriptEngine and a set of attributes is maintained for each engine.
  See Also:
  Constant Field Values

  • GLOBAL_SCOPE

  static final int GLOBAL_SCOPE
  GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.
  See Also:
  Constant Field Values

• Method Details

  • setBindings

  void setBindings​(Bindings bindings, int scope)
  Associates a Bindings instance with a particular scope in thisScriptContext. Calls to the getAttribute andsetAttribute methods must map to the get andput methods of the Bindings for the specified scope.
  Parameters:
  bindings - The Bindings to associate with the given scope
  scope - The scope
  Throws:
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - If no Bindings is defined for the specified scope value in ScriptContexts of this type.
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if value of scope is ENGINE_SCOPE and the specified Bindings is null.

  • getBindings

  Gets the Bindings associated with the given scope in thisScriptContext.
  Parameters:
  scope - The scope
  Returns:
  The associated Bindings. Returns null if it has not been set.
  Throws:
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - If no Bindings is defined for the specified scope value in ScriptContext of this type.

  • setAttribute

  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.
  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](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if the name is empty or if the scope is invalid.
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if the name is null.

  • getAttribute

  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](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if the name is empty or if the value of scope is invalid.
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if the name is null.

  • removeAttribute

  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](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if the name is empty or if the scope is invalid.
  [NullPointerException](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if the name is null.

  • getAttribute

  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 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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if the name is null.
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if the name is empty.

  • getAttributesScope

  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](../../../java.base/java/lang/NullPointerException.html "class in java.lang") - if name is null.
  [IllegalArgumentException](../../../java.base/java/lang/IllegalArgumentException.html "class in java.lang") - if name is empty.

  • getWriter

  Returns the Writer for scripts to use when displaying output.
  Returns:
  The Writer.

  • getErrorWriter

  Returns the Writer used to display error output.
  Returns:
  The Writer

  • setWriter

  void setWriter​(Writer writer)
  Sets the Writer for scripts to use when displaying output.
  Parameters:
  writer - The new Writer.

  • setErrorWriter

  void setErrorWriter​(Writer writer)
  Sets the Writer used to display error output.
  Parameters:
  writer - The Writer.

  • getReader

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

  • setReader

  void setReader​(Reader reader)
  Sets the Reader for scripts to read input .
  Parameters:
  reader - The new Reader.

  • getScopes

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