Interface ScriptContext
- 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
Fields
Modifier and Type | Field and Description |
---|---|
static int |
ENGINE_SCOPE EngineScope attributes are visible during the lifetime of a single |
static int |
GLOBAL_SCOPE GlobalScope attributes are visible to all engines created by same ScriptEngineFactory. |
Methods
Modifier and Type | Method and 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 |
Writer |
getErrorWriter() Returns the |
Reader |
getReader() Returns a |
List<Integer> |
getScopes() Returns immutable |
Writer |
getWriter() Returns the |
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 |
void |
setErrorWriter(Writer writer) Sets the |
void |
setReader(Reader reader) Sets the |
void |
setWriter(Writer writer) Sets the |
Fields
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
GLOBAL_SCOPE
static final int GLOBAL_SCOPE
GlobalScope attributes are visible to all engines created by same ScriptEngineFactory.
- See Also:
- Constant Field Values
Methods
setBindings
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
- TheBindings
to associate with the given scope -
scope
- The scope - Throws:
-
IllegalArgumentException
- If noBindings
is defined for the specified scope value in ScriptContexts of this type. -
NullPointerException
- if value of scope isENGINE_SCOPE
and the specifiedBindings
is null.
getBindings
Bindings getBindings(int scope)
Gets the Bindings
associated with the given scope in this ScriptContext
.
- Parameters:
-
scope
- The scope - Returns:
- The associated
Bindings
. Returnsnull
if it has not been set. - Throws:
-
IllegalArgumentException
- If noBindings
is defined for the specified scope value inScriptContext
of this type.
setAttribute
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.
getAttribute
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.
removeAttribute
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.
getAttribute
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.
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
- if name is null. -
IllegalArgumentException
- if name is empty.
getWriter
Writer getWriter()
Returns the Writer
for scripts to use when displaying output.
- Returns:
- The
Writer
.
getErrorWriter
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 newWriter
.
setErrorWriter
void setErrorWriter(Writer writer)
Sets the Writer
used to display error output.
- Parameters:
-
writer
- TheWriter
.
getReader
Reader 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 newReader
.
getScopes
List<Integer> getScopes()
Returns immutable List
of all the valid values for scope in the ScriptContext.
- Returns:
- list of scope values
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https://docs.oracle.com/javase/8/docs/api/javax/script/ScriptContext.html