Class OptionalELResolver
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescription<T> T
convertToType
(ELContext context, Object obj, Class<T> type) Converts the given object to the given type.Class
<?> getCommonPropertyType
(ELContext context, Object base) Obtain the most common type that is acceptable for the given base object.Class
<?> Obtain the most generally acceptable type that may be used to set the given property on the given object using the given context.Obtain the value of the given property on the given object using the given context.Invokes a method on the the given object.boolean
isReadOnly
(ELContext context, Object base, Object property) Determine if the given property on the given object is read-only using the given context.void
Set the value of the given property on the given object using the given context.
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Constructor Details
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OptionalELResolver
public OptionalELResolver()
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Method Details
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getValue
Obtain the value of the given property on the given object using the given context.- Specified by:
getValue
in classELResolver
- Parameters:
context
- The EL context for this evaluationbase
- The base object on which the property is to be foundproperty
- The property whose value is to be returned- Returns:
- If the base object is an
Optional
andOptional.isEmpty()
returnstrue
then the resulting value isnull
.If the base object is an
Optional
,Optional.isPresent()
returnstrue
and the property isnull
then the resulting value is the result of callingOptional.get()
on the base object.If the base object is an
Optional
,Optional.isPresent()
returnstrue
and the property is notnull
then the resulting value is the result of callingELResolver.getValue(ELContext, Object, Object)
using theELResolver
obtained fromELContext.getELResolver()
with the following parameters:- The
ELContext
is the current context - The base object is the result of calling
Optional.get()
on the current base object - The property object is the current property object
If the base object is not an
Optional
then the return value is undefined. - The
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getType
Obtain the most generally acceptable type that may be used to set the given property on the given object using the given context.- Specified by:
getType
in classELResolver
- Parameters:
context
- The EL context for this evaluationbase
- The base object on which the property is to be foundproperty
- The property whose type is to be returned- Returns:
- If the base object is an
Optional
this method always returnsnull
since instances of this resolver are always read-only.If the base object is not an
Optional
then the return value is undefined.
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setValue
Set the value of the given property on the given object using the given context.If the base object is an
Optional
this method always throws aPropertyNotWritableException
since instances of this resolver are always read-only.- Specified by:
setValue
in classELResolver
- Parameters:
context
- The EL context for this evaluationbase
- The base object on which the property is to be foundproperty
- The property whose value is to be setvalue
- The value to set the property to
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isReadOnly
Determine if the given property on the given object is read-only using the given context.- Specified by:
isReadOnly
in classELResolver
- Parameters:
context
- The EL context for this evaluationbase
- The base object on which the property is to be foundproperty
- The property to be checked for read only status- Returns:
- If the base object is an
Optional
this method always returnstrue
since instances of this resolver are always read-only.If the base object is not an
Optional
then the return value is undefined.
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getCommonPropertyType
Obtain the most common type that is acceptable for the given base object.- Specified by:
getCommonPropertyType
in classELResolver
- Parameters:
context
- The context in which the examination takes placebase
- The object to examine- Returns:
- If the base object is an
Optional
this method always returnsObject.class
.If the base object is not an
Optional
then the return value is undefined.
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convertToType
Converts the given object to the given type.- Overrides:
convertToType
in classELResolver
- Type Parameters:
T
- The type to which the object should be converted- Parameters:
context
- The EL context for this evaluationobj
- The object to converttype
- The type to which the object should be converted- Returns:
- If the base object is an
Optional
andOptional.isEmpty()
returnstrue
then this method returns the result of coercingnull
to the requestedtype
.If the base object is an
Optional
andOptional.isPresent()
returnstrue
then this method returns the result of coercingOptional#get()
to the requestedtype
.If the base object is not an
Optional
then the return value is undefined.
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invoke
public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params) Invokes a method on the the given object.- Overrides:
invoke
in classELResolver
- Parameters:
context
- The EL context for this evaluationbase
- The base object on which the method is to be foundmethod
- The method to invokeparamTypes
- The types of the parameters of the method to invokeparams
- The parameters with which to invoke the method- Returns:
- If the base object is an
Optional
andOptional.isEmpty()
returnstrue
then this method returnsnull
.If the base object is an
Optional
andOptional.isPresent()
returnstrue
then this method returns the result of invoking the specified method on the object obtained by callingOptional.get()
with the specified parameters.If the base object is not an
Optional
then the return value is undefined.
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