| java.lang.Object
 javax.el.ELResolver
javax.el.BeanELResolver
| BeanELResolver | | public class BeanELResolver extends ELResolver (Code) | | Defines property resolution behavior on objects using the JavaBeans
component architecture.
This resolver handles base objects of any type, as long as the
base is not null. It accepts any object as a property, and
coerces it to a string. That string is then used to find a JavaBeans
compliant property on the base object. The value is accessed using
JavaBeans getters and setters.
This resolver can be constructed in read-only mode, which means that
BeanELResolver.isReadOnly will always return true and
BeanELResolver.setValue 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.
Because this resolver handles base objects of any type, it should
be placed near the end of a composite resolver. Otherwise, it will
claim to have resolved a property before any resolvers that come after
it get a chance to test if they can do so as well.
See Also: CompositeELResolver
See Also: ELResolver
since:
JSP 2.1 |
| Inner Class :final protected static class BeanProperty | |
| Inner Class :final protected static class BeanProperties | |
| Constructor Summary | |
| public | BeanELResolver()
Creates a new read/write BeanELResolver. | | public | BeanELResolver(boolean isReadOnly)
Creates a new BeanELResolver whose read-only status is
determined by the given parameter. |
| Method Summary | |
| public Class | getCommonPropertyType(ELContext context, Object base)
If the base object is not null, returns the most
general type that this resolver accepts for the
property argument. | | public Iterator<FeatureDescriptor> | getFeatureDescriptors(ELContext context, Object base)
If the base object is not null, returns an
Iterator containing the set of JavaBeans properties
available on the given object. | | public Class | getType(ELContext context, Object base, Object property)
If the base object is not null, returns the most
general acceptable type that can be set on this bean property.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. | | public Object | getValue(ELContext context, Object base, Object property)
If the base object is not null, returns the current
value of the given property on this bean.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. | | public boolean | isReadOnly(ELContext context, Object base, Object property)
If the base object is not null, returns whether a call
to
BeanELResolver.setValue will always fail.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. | | public void | setValue(ELContext context, Object base, Object property, Object val)
If the base object is not null, attempts to set the
value of the given property on this bean.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. |
| BeanELResolver | | public BeanELResolver()(Code) | | Creates a new read/write BeanELResolver.
|
| BeanELResolver | | public BeanELResolver(boolean isReadOnly)(Code) | | Creates a new BeanELResolver whose read-only status is
determined by the given parameter.
Parameters:
isReadOnly - true if this resolver cannot modifybeans; false otherwise. |
| getCommonPropertyType | | public Class getCommonPropertyType(ELContext context, Object base)(Code) | | If the base object is not null, returns the most
general type that this resolver accepts for the
property argument. Otherwise, returns null.
Assuming the base is not null, this method will always
return Object.class. This is because any object is
accepted as a key and is coerced into a string.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean to analyze. null if base is null; otherwiseObject.class. |
| getFeatureDescriptors | | public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base)(Code) | | If the base object is not null, returns an
Iterator containing the set of JavaBeans properties
available on the given object. Otherwise, returns null.
The Iterator returned must contain zero or more
instances of
java.beans.FeatureDescriptor . Each info object
contains information about a property in the bean, as obtained by
calling the BeanInfo.getPropertyDescriptors method.
The FeatureDescriptor is initialized using the same
fields as are present in the PropertyDescriptor,
with the additional required named attributes "type" and
"resolvableAtDesignTime" set as follows:
ELResolver.TYPE - The runtime type of the property, from
PropertyDescriptor.getPropertyType().
ELResolver.RESOLVABLE_AT_DESIGN_TIME - true.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean to analyze. An Iterator containing zero or more FeatureDescriptor objects, each representing a propertyon this bean, or null if the baseobject is null. |
| getType | | public Class getType(ELContext context, Object base, Object property)(Code) | | If the base object is not null, returns the most
general acceptable type that can be set on this bean property.
If the base is not null, 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.
The provided property will first be coerced to a String.
If there is a BeanInfoProperty for this property and
there were no errors retrieving it, the propertyType of
the propertyDescriptor is returned. Otherwise, a
PropertyNotFoundException is thrown.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean to analyze.
Parameters:
property - The name of the property to analyze. Will be coerced toa String. If the propertyResolved property of ELContext was set to true, thenthe most general acceptable type; otherwise undefined.
throws:
NullPointerException - if context is null
throws:
PropertyNotFoundException - if base is notnull and the specified property does not existor is not readable.
throws:
ELException - if an exception was thrown while performingthe property or variable resolution. The thrown exceptionmust be included as the cause property of this exception, ifavailable. |
| getValue | | public Object getValue(ELContext context, Object base, Object property)(Code) | | If the base object is not null, returns the current
value of the given property on this bean.
If the base is not null, 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.
The provided property name will first be coerced to a
String. If the property is a readable property of the
base object, as per the JavaBeans specification, then return the
result of the getter call. If the getter throws an exception,
it is propagated to the caller. If the property is not found or is
not readable, a PropertyNotFoundException is thrown.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean on which to get the property.
Parameters:
property - The name of the property to get. Will be coerced toa String. If the propertyResolved property of ELContext was set to true, thenthe value of the given property. Otherwise, undefined.
throws:
NullPointerException - if context is null.
throws:
PropertyNotFoundException - if base is notnull and the specified property does not existor is not readable.
throws:
ELException - if an exception was thrown while performingthe property or variable resolution. The thrown exceptionmust be included as the cause property of this exception, ifavailable. |
| isReadOnly | | public boolean isReadOnly(ELContext context, Object base, Object property)(Code) | | If the base object is not null, returns whether a call
to
BeanELResolver.setValue will always fail.
If the base is not null, 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 can safely assume no value was set.
If this resolver was constructed in read-only mode, this method will
always return true.
The provided property name will first be coerced to a
String. If property is a writable property of
base, false is returned. If the property is
found but is not writable, true is returned. If the
property is not found, a PropertyNotFoundException
is thrown.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean to analyze.
Parameters:
property - The name of the property to analyzed. Will be coerced toa String. If the propertyResolved property of ELContext was set to true, thentrue if calling the setValue methodwill always fail or false if it is possible thatsuch a call may succeed; otherwise undefined.
throws:
NullPointerException - if context is null
throws:
PropertyNotFoundException - if base is notnull and the specified property does not exist.
throws:
ELException - if an exception was thrown while performingthe property or variable resolution. The thrown exceptionmust be included as the cause property of this exception, ifavailable. |
| setValue | | public void setValue(ELContext context, Object base, Object property, Object val)(Code) | | If the base object is not null, attempts to set the
value of the given property on this bean.
If the base is not null, 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 can safely assume no value was set.
If this resolver was constructed in read-only mode, this method will
always throw PropertyNotWritableException.
The provided property name will first be coerced to a
String. If property is a writable property of
base (as per the JavaBeans Specification), the setter
method is called (passing value). If the property exists
but does not have a setter, then a
PropertyNotFoundException is thrown. If the property
does not exist, a PropertyNotFoundException is thrown.
Parameters:
context - The context of this evaluation.
Parameters:
base - The bean on which to set the property.
Parameters:
property - The name of the property to set. Will be coerced toa String.
Parameters:
val - The value to be associated with the specified key.
throws:
NullPointerException - if context is null.
throws:
PropertyNotFoundException - if base is notnull and the specified property does not exist.
throws:
PropertyNotWritableException - if this resolver was constructedin read-only mode, or if there is no setter for the property.
throws:
ELException - if an exception was thrown while performingthe property or variable resolution. The thrown exceptionmust be included as the cause property of this exception, ifavailable. |
| Methods inherited from javax.el.ELResolver | abstract public Class getCommonPropertyType(ELContext context, Object base)(Code)(Java Doc)
abstract public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base)(Code)(Java Doc)
abstract public Class getType(ELContext context, Object base, Object property)(Code)(Java Doc)
abstract public Object getValue(ELContext context, Object base, Object property)(Code)(Java Doc)
abstract public boolean isReadOnly(ELContext context, Object base, Object property)(Code)(Java Doc)
abstract public void setValue(ELContext context, Object base, Object property, Object value)(Code)(Java Doc)
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