Package javax.el
Class ELResolver
- java.lang.Object
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- javax.el.ELResolver
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- Direct Known Subclasses:
ArrayELResolver
,BeanELResolver
,BeanNameELResolver
,CompositeELResolver
,ListELResolver
,MapELResolver
,ResourceBundleELResolver
,StaticFieldELResolver
,TypeConverter
public abstract class ELResolver extends java.lang.Object
- Author:
- Jacob Hookom [jacob/hookom.net]
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Field Summary
Fields Modifier and Type Field Description static java.lang.String
RESOLVABLE_AT_DESIGN_TIME
static java.lang.String
TYPE
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Constructor Summary
Constructors Constructor Description ELResolver()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description java.lang.Object
convertToType(ELContext context, java.lang.Object obj, java.lang.Class<?> type)
Converts the given object to the given type.abstract java.lang.Class<?>
getCommonPropertyType(ELContext context, java.lang.Object base)
Obtain the most common type that is acceptable for the given base object.abstract java.util.Iterator<java.beans.FeatureDescriptor>
getFeatureDescriptors(ELContext context, java.lang.Object base)
Obtain the feature descriptors for the resolvable properties of the given object.abstract java.lang.Class<?>
getType(ELContext context, java.lang.Object base, java.lang.Object property)
Obtain the most generally acceptable type that may be used to set the given property on the given object using the given context.abstract java.lang.Object
getValue(ELContext context, java.lang.Object base, java.lang.Object property)
Obtain the value of the given property on the given object using the given context.java.lang.Object
invoke(ELContext context, java.lang.Object base, java.lang.Object method, java.lang.Class<?>[] paramTypes, java.lang.Object[] params)
Invokes a method on the the given object.abstract boolean
isReadOnly(ELContext context, java.lang.Object base, java.lang.Object property)
Determine if the given property on the given object is read-only using the given context.abstract void
setValue(ELContext context, java.lang.Object base, java.lang.Object property, java.lang.Object value)
Set the value of the given property on the given object using the given context.
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Field Detail
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TYPE
public static final java.lang.String TYPE
- See Also:
- Constant Field Values
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RESOLVABLE_AT_DESIGN_TIME
public static final java.lang.String RESOLVABLE_AT_DESIGN_TIME
- See Also:
- Constant Field Values
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Method Detail
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getValue
public abstract java.lang.Object getValue(ELContext context, java.lang.Object base, java.lang.Object property)
Obtain the value of the given property on the given object using the given context.- 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:
- the value of the provided property
- Throws:
java.lang.NullPointerException
- If the supplied context isnull
PropertyNotFoundException
- If the base/property combination provided to the resolver is one that the resolver can handle but no match was found or a match was found but was not readableELException
- Wraps any exception throw whilst resolving the property
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invoke
public java.lang.Object invoke(ELContext context, java.lang.Object base, java.lang.Object method, java.lang.Class<?>[] paramTypes, java.lang.Object[] params)
Invokes a method on the the given object. This default implementation always returnsnull
.- 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:
- Always
null
- Since:
- EL 2.2
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getType
public abstract java.lang.Class<?> getType(ELContext context, java.lang.Object base, java.lang.Object property)
Obtain the most generally acceptable type that may be used to set the given property on the given object using the given context.- 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:
- the most general type that maybe used to set the provided property or
null
if the resolver is read-only. - Throws:
java.lang.NullPointerException
- If the supplied context isnull
PropertyNotFoundException
- If the base/property combination provided to the resolver is one that the resolver can handle but no match was found or a match was found but was not readableELException
- Wraps any exception throw whilst resolving the property
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setValue
public abstract void setValue(ELContext context, java.lang.Object base, java.lang.Object property, java.lang.Object value)
Set the value of the given property on the given object using the given context.- 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- Throws:
java.lang.NullPointerException
- If the supplied context isnull
PropertyNotFoundException
- If the base/property combination provided to the resolver is one that the resolver can handle but no match was foundPropertyNotWritableException
- If the base/property combination provided to the resolver is one that the resolver can handle but the property was not writableELException
- Wraps any exception throw whilst resolving the property
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isReadOnly
public abstract boolean isReadOnly(ELContext context, java.lang.Object base, java.lang.Object property)
Determine if the given property on the given object is read-only using the given context.- 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:
true
if the identified property is read only, otherwisefalse
- Throws:
java.lang.NullPointerException
- If the supplied context isnull
PropertyNotFoundException
- If the base/property combination provided to the resolver is one that the resolver can handle but no match was foundELException
- Wraps any exception throw whilst resolving the property
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getFeatureDescriptors
public abstract java.util.Iterator<java.beans.FeatureDescriptor> getFeatureDescriptors(ELContext context, java.lang.Object base)
Obtain the feature descriptors for the resolvable properties of the given object.- Parameters:
context
- The context in which the examination takes placebase
- The object to examine- Returns:
- An iterator, possibly empty, of feature descriptors of the given object
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getCommonPropertyType
public abstract java.lang.Class<?> getCommonPropertyType(ELContext context, java.lang.Object base)
Obtain the most common type that is acceptable for the given base object.- Parameters:
context
- The context in which the examination takes placebase
- The object to examine- Returns:
- {code null} if the most common type cannot be determine, otherwise the most common type
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convertToType
public java.lang.Object convertToType(ELContext context, java.lang.Object obj, java.lang.Class<?> type)
Converts the given object to the given type. This default implementation always returnsnull
.- Parameters:
context
- The EL context for this evaluationobj
- The object to converttype
- The type to which the object should be converted- Returns:
- Always
null
- Since:
- EL 3.0
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