- All Known Implementing Classes:
SimpleScriptContext
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 the
ScriptContext methods. ScriptContexts also expose Readers and Writers
that can be used by the ScriptEngines for input and output.- Since:
- 1.6
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intEngineScope attributes are visible during the lifetime of a singleScriptEngineand a set of attributes is maintained for each engine.static final intGlobalScope attributes are visible to all engines created by same ScriptEngineFactory. -
Method Summary
Modifier and TypeMethodDescriptiongetAttribute(String name) Retrieves the value of the attribute with the given name in the scope occurring earliest in the search order.getAttribute(String name, int scope) Gets the value of an attribute in a given scope.intgetAttributesScope(String name) Get the lowest scope in which an attribute is defined.getBindings(int scope) Gets theBindingsassociated with the given scope in thisScriptContext.Returns theWriterused to display error output.Returns aReaderto be used by the script to read input.Returns immutableListof all the valid values for scope in the ScriptContext.Returns theWriterfor scripts to use when displaying output.removeAttribute(String name, int scope) Remove an attribute in a given scope.voidsetAttribute(String name, Object value, int scope) Sets the value of an attribute in a given scope.voidsetBindings(Bindings bindings, int scope) Associates aBindingsinstance with a particular scope in thisScriptContext.voidsetErrorWriter(Writer writer) Sets theWriterused to display error output.voidSets theReaderfor scripts to read input .voidSets theWriterfor scripts to use when displaying output.
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Field Details
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ENGINE_SCOPE
static final int ENGINE_SCOPEEngineScope attributes are visible during the lifetime of a singleScriptEngineand a set of attributes is maintained for each engine.- See Also:
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GLOBAL_SCOPE
static final int GLOBAL_SCOPEGlobalScope attributes are visible to all engines created by same ScriptEngineFactory.- See Also:
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Method Details
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setBindings
Associates aBindingsinstance with a particular scope in thisScriptContext. Calls to thegetAttributeandsetAttributemethods must map to thegetandputmethods of theBindingsfor the specified scope.- Parameters:
bindings- TheBindingsto associate with the given scopescope- The scope- Throws:
IllegalArgumentException- If noBindingsis defined for the specified scope value in ScriptContexts of this type.NullPointerException- if value of scope isENGINE_SCOPEand the specifiedBindingsis null.
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getBindings
Gets theBindingsassociated with the given scope in thisScriptContext.- Parameters:
scope- The scope- Returns:
- The associated
Bindings. Returnsnullif it has not been set. - Throws:
IllegalArgumentException- If noBindingsis defined for the specified scope value inScriptContextof this type.
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setAttribute
Sets the value of an attribute in a given scope. If the scope isGLOBAL_SCOPEand no Bindings is set forGLOBAL_SCOPE, then setAttribute call is a no-op.- Parameters:
name- The name of the attribute to setvalue- The value of the attributescope- 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.
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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
nullis 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.
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removeAttribute
Remove an attribute in a given scope.- Parameters:
name- The name of the attribute to removescope- 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.
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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- if the name is null.IllegalArgumentException- if the name is empty.
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getAttributesScope
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.
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getWriter
Writer getWriter()Returns theWriterfor scripts to use when displaying output.- Returns:
- The
Writer.
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getErrorWriter
Writer getErrorWriter()Returns theWriterused to display error output.- Returns:
- The
Writer
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setWriter
Sets theWriterfor scripts to use when displaying output.- Parameters:
writer- The newWriter.
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setErrorWriter
Sets theWriterused to display error output.- Parameters:
writer- TheWriter.
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getReader
Reader getReader()Returns aReaderto be used by the script to read input.- Returns:
- The
Reader.
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setReader
Sets theReaderfor scripts to read input .- Parameters:
reader- The newReader.
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getScopes
Returns immutableListof all the valid values for scope in the ScriptContext.- Returns:
- list of scope values
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