public class ListELResolver extends ELResolver
setValue(ELContext, Object, Object, Object)
will always throw
PropertyNotWritableException. ELResolvers are combined together using CompositeELResolver
s, to define rich semantics for evaluating an expression. See the javadocs for ELResolver
for details.RESOLVABLE_AT_DESIGN_TIME, TYPE
Constructor and Description |
---|
ListELResolver()
Creates a new read/write ListELResolver.
|
ListELResolver(boolean readOnly)
Creates a new ListELResolver whose read-only status is determined by the given parameter.
|
Modifier and Type | Method and Description |
---|---|
Class<?> |
getCommonPropertyType(ELContext context,
Object base)
If the base object is a list, returns the most general type that this resolver accepts for
the property argument.
|
Iterator<FeatureDescriptor> |
getFeatureDescriptors(ELContext context,
Object base)
Always returns null, since there is no reason to iterate through set set of all integers.
|
Class<?> |
getType(ELContext context,
Object base,
Object property)
If the base object is a list, returns the most general acceptable type for a value in this
list.
|
Object |
getValue(ELContext context,
Object base,
Object property)
If the base object is a list, returns the value at the given index.
|
boolean |
isReadOnly(ELContext context,
Object base,
Object property)
If the base object is a list, returns whether a call to
setValue(ELContext, Object, Object, Object) will always fail. |
void |
setValue(ELContext context,
Object base,
Object property,
Object value)
If the base object is a list, attempts to set the value at the given index with the given
value.
|
invoke
public ListELResolver()
public ListELResolver(boolean readOnly)
readOnly
- true if this resolver cannot modify lists; false otherwise.public Class<?> getCommonPropertyType(ELContext context, Object base)
getCommonPropertyType
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base)
getFeatureDescriptors
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.public Class<?> getType(ELContext context, Object base, Object property)
getType
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.property
- The index of the element in the list to return the acceptable type for. Will be
coerced into an integer, but otherwise ignored by this resolver.PropertyNotFoundException
- if the given index is out of bounds for this list.IllegalArgumentException
- if the property could not be coerced into an integer.NullPointerException
- if context is nullELException
- 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.public Object getValue(ELContext context, Object base, Object property)
getValue
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.property
- The index of the element in the list to return the acceptable type for. Will be
coerced into an integer, but otherwise ignored by this resolver.PropertyNotFoundException
- if the given index is out of bounds for this list.IllegalArgumentException
- if the property could not be coerced into an integer.NullPointerException
- if context is nullELException
- 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.public boolean isReadOnly(ELContext context, Object base, Object property)
setValue(ELContext, Object, Object, Object)
will always fail. If the base is a List,
the propertyResolved property of the ELContext object must be set to true by this resolver,
before returning. If this property is not true after this method is called, the caller should
ignore the return value. If this resolver was constructed in read-only mode, this method will
always return true. If a List was created using java.util.Collections.unmodifiableList(List),
this method must return true. Unfortunately, there is no Collections API method to detect
this. However, an implementation can create a prototype unmodifiable List and query its
runtime type to see if it matches the runtime type of the base object as a workaround.isReadOnly
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.property
- The index of the element in the list to return the acceptable type for. Will be
coerced into an integer, but otherwise ignored by this resolver.PropertyNotFoundException
- if the given index is out of bounds for this list.IllegalArgumentException
- if the property could not be coerced into an integer.NullPointerException
- if context is nullELException
- 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.public void setValue(ELContext context, Object base, Object property, Object value)
setValue
in class ELResolver
context
- The context of this evaluation.base
- The list to analyze. Only bases of type List are handled by this resolver.property
- The index of the element in the list to return the acceptable type for. Will be
coerced into an integer, but otherwise ignored by this resolver.value
- The value to be set at the given index.ClassCastException
- if the class of the specified element prevents it from being added to this list.PropertyNotFoundException
- if the given index is out of bounds for this list.PropertyNotWritableException
- if this resolver was constructed in read-only mode, or if the set operation is
not supported by the underlying list.IllegalArgumentException
- if the property could not be coerced into an integer.NullPointerException
- if context is nullELException
- 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.Copyright © 2017. All rights reserved.