Class ScopedAttributeELResolver
- java.lang.Object
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- jakarta.el.ELResolver
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- jakarta.servlet.jsp.el.ScopedAttributeELResolver
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public class ScopedAttributeELResolver extends ELResolver
Defines variable resolution behavior for scoped attributes.This resolver handles variable resolutions where
base
isnull
. It searchesPageContext.findAttribute()
for a matching attribute. If not found in the case ofsetValue
, it will create a new attribute in the page scope with the given name.- Since:
- JSP 2.1
- See Also:
ELResolver
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Field Summary
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Fields inherited from class jakarta.el.ELResolver
RESOLVABLE_AT_DESIGN_TIME, TYPE
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Constructor Summary
Constructors Constructor Description ScopedAttributeELResolver()
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description Class<String>
getCommonPropertyType(ELContext context, Object base)
If the base object isnull
, returnsString.class
.Iterator<FeatureDescriptor>
getFeatureDescriptors(ELContext context, Object base)
Deprecated, for removal: This API element is subject to removal in a future version.This method is deprecated as of EL 5.0 and will be removed in EL 6.0 (Jakarta EE 11).Class<Object>
getType(ELContext context, Object base, Object property)
If the base object isnull
, returnsObject.class
to indicate that any type is valid to set for a scoped attribute.Object
getValue(ELContext context, Object base, Object property)
If the base object isnull
, searches the page, request, session and application scopes for an attribute with the given name and returns it if an attribute exists with the current name.boolean
isReadOnly(ELContext context, Object base, Object property)
If the base object isnull
, returnsfalse
to indicate that scoped attributes are never read-only.void
setValue(ELContext context, Object base, Object property, Object val)
If the base object isnull
, sets an existing scoped attribute to the new value, or creates a new scoped attribute if one does not exist by this name.-
Methods inherited from class jakarta.el.ELResolver
convertToType, invoke
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Method Detail
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getValue
public Object getValue(ELContext context, Object base, Object property)
If the base object isnull
, searches the page, request, session and application scopes for an attribute with the given name and returns it if an attribute exists with the current name.The
propertyResolved
property of theELContext
object must be set totrue
by this resolver before returning if a scoped attribute is matched. If this property is nottrue
after this method is called, the caller should ignore the return value.- Specified by:
getValue
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in an immediate return.property
- The name of the scoped attribute to resolve.- Returns:
- If the
propertyResolved
property ofELContext
was set totrue
, then the scoped attribute; otherwise undefined. - Throws:
NullPointerException
- if context isnull
ELException
- if an exception was thrown while performing the property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.
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getType
public Class<Object> getType(ELContext context, Object base, Object property)
If the base object isnull
, returnsObject.class
to indicate that any type is valid to set for a scoped attribute.The
propertyResolved
property of theELContext
object must be set totrue
by this resolver before returning if base isnull
. If this property is nottrue
after this method is called, the caller should ignore the return value.- Specified by:
getType
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in an immediate return.property
- The name of the scoped attribute to resolve.- Returns:
- If the
propertyResolved
property ofELContext
was set totrue
, thenObject.class
; otherwise undefined. - Throws:
NullPointerException
- if context isnull
ELException
- if an exception was thrown while performing the property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.
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setValue
public void setValue(ELContext context, Object base, Object property, Object val)
If the base object isnull
, sets an existing scoped attribute to the new value, or creates a new scoped attribute if one does not exist by this name.If the provided attribute name matches the key of an attribute in page scope, request scope, session scope, or application scope, the corresponding attribute value will be replaced by the provided value. Otherwise, a new page scope attribute will be created with the given name and value.
The
propertyResolved
property of theELContext
object must be set totrue
by this resolver before returning if base isnull
. If this property is nottrue
after this method is called, the caller should ignore the return value.- Specified by:
setValue
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in an immediate return.property
- The name of the scoped attribute to set.val
- The value for the scoped attribute.- Throws:
NullPointerException
- if context isnull
.ELException
- if an exception was thrown while performing the property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.
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isReadOnly
public boolean isReadOnly(ELContext context, Object base, Object property)
If the base object isnull
, returnsfalse
to indicate that scoped attributes are never read-only.The
propertyResolved
property of theELContext
object must be set totrue
by this resolver before returning if base isnull
. If this property is nottrue
after this method is called, the caller should ignore the return value.- Specified by:
isReadOnly
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in an immediate return.property
- The name of the scoped attribute.- Returns:
- If the
propertyResolved
property ofELContext
was set totrue
, thenfalse
; otherwise undefined. - Throws:
NullPointerException
- if context isnull
.ELException
- if an exception was thrown while performing the property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.
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getFeatureDescriptors
@Deprecated(forRemoval=true, since="JSP 3.1") public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base)
Deprecated, for removal: This API element is subject to removal in a future version.This method is deprecated as of EL 5.0 and will be removed in EL 6.0 (Jakarta EE 11). Therefore it will be removed here in JSP 4.0.If the base object isnull
, returns anIterator
containingFeatureDescriptor
objects with information about each scoped attribute resolved by this resolver. Otherwise, returnsnull
.The
Iterator
returned must contain one instance ofFeatureDescriptor
for each scoped attribute found in any scope. Each info object contains information about a single scoped attribute, and is initialized as follows:- displayName
- - The name of the scoped attribute.
- name
- - Same as displayName property.
- shortDescription
- - A suitable description for the scoped attribute. Should include the attribute's current scope (page, request, session, application). Will vary by implementation.
- expert
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false
- hidden
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false
- preferred
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true
FeatureDescriptor
s:ELResolver.TYPE
- - The current runtime type of the scoped attribute.
ELResolver.RESOLVABLE_AT_DESIGN_TIME
- -
true
.
- Overrides:
getFeatureDescriptors
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in anull
return value.- Returns:
- An
Iterator
containing oneFeatureDescriptor
object for each scoped attribute, ornull
ifbase
is notnull
. - See Also:
FeatureDescriptor
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getCommonPropertyType
public Class<String> getCommonPropertyType(ELContext context, Object base)
If the base object isnull
, returnsString.class
. Otherwise, returnsnull
.- Specified by:
getCommonPropertyType
in classELResolver
- Parameters:
context
- The context of this evaluation.base
- Onlynull
is handled by this resolver. Other values will result in anull
return value.- Returns:
null
if base is notnull
; otherwiseString.class
.
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