ScriptContext (Java SE 12 & JDK 12 ) (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

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

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)	Gets the Bindings associated with the given scope in thisScriptContext.
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)	Associates a Bindings instance with a particular scope in thisScriptContext.
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.

Field Detail

 * #### ENGINE\_SCOPE  
 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.  
 See Also:  
 [Constant Field Values](../../../constant-values.html#javax.script.ScriptContext.ENGINE%5FSCOPE)  
 * #### GLOBAL\_SCOPE  
 static final int GLOBAL_SCOPE  
 GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.  
 See Also:  
 [Constant Field Values](../../../constant-values.html#javax.script.ScriptContext.GLOBAL%5FSCOPE)

Method Detail

* #### setBindings  
void setBindings([Bindings](Bindings.html "interface in javax.script") 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](../../../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  
[Bindings](Bindings.html "interface in javax.script") getBindings(int scope)  
Gets the `Bindings` associated with the given scope in this`ScriptContext`.  
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](../../../java.base/java/lang/String.html "class in java.lang") name,  
                  [Object](../../../java.base/java/lang/Object.html "class in java.lang") 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  
[Object](../../../java.base/java/lang/Object.html "class in java.lang") getAttribute([String](../../../java.base/java/lang/String.html "class in java.lang") 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](../../../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  
[Object](../../../java.base/java/lang/Object.html "class in java.lang") removeAttribute([String](../../../java.base/java/lang/String.html "class in java.lang") 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](../../../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  
[Object](../../../java.base/java/lang/Object.html "class in java.lang") getAttribute([String](../../../java.base/java/lang/String.html "class in java.lang") 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 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](../../../java.base/java/lang/String.html "class in java.lang") 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  
[Writer](../../../java.base/java/io/Writer.html "class in java.io") getWriter()  
Returns the `Writer` for scripts to use when displaying output.  
Returns:  
The `Writer`.  
* #### getErrorWriter  
[Writer](../../../java.base/java/io/Writer.html "class in java.io") getErrorWriter()  
Returns the `Writer` used to display error output.  
Returns:  
The `Writer`  
* #### setWriter  
void setWriter([Writer](../../../java.base/java/io/Writer.html "class in java.io") writer)  
Sets the `Writer` for scripts to use when displaying output.  
Parameters:  
`writer` \- The new `Writer`.  
* #### setErrorWriter  
void setErrorWriter([Writer](../../../java.base/java/io/Writer.html "class in java.io") writer)  
Sets the `Writer` used to display error output.  
Parameters:  
`writer` \- The `Writer`.  
* #### getReader  
[Reader](../../../java.base/java/io/Reader.html "class in java.io") getReader()  
Returns a `Reader` to be used by the script to read input.  
Returns:  
The `Reader`.  
* #### setReader  
void setReader([Reader](../../../java.base/java/io/Reader.html "class in java.io") reader)  
Sets the `Reader` for scripts to read input .  
Parameters:  
`reader` \- The new `Reader`.  
* #### getScopes  
[List](../../../java.base/java/util/List.html "interface in java.util")<[Integer](../../../java.base/java/lang/Integer.html "class in java.lang")> getScopes()  
Returns immutable `List` of all the valid values for scope in the ScriptContext.  
Returns:  
list of scope values

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ScriptContext (Java SE 12 & JDK 12 ) (original) (raw)

Field Summary

Method Summary

Field Detail

Method Detail