T
- The generic type of object value to validate.public interface Validator<T>
extends java.util.EventListener
A Validator
implementation is a class that can perform validation (correctness
checks) on a EditableValueHolder
. Zero
or more Validator
s can be associated with each EditableValueHolder
in the view, and are
called during the Process Validations phase of the request
processing lifecycle.
Individual Validator
s should examine the value and
component that they are passed, and throw a ValidatorException
containing a FacesMessage
, documenting
any failures to conform to the required rules.
For maximum generality, Validator
instances may be
configurable based on properties of the Validator
implementation
class. For example, a range check Validator
might support
configuration of the minimum and maximum values to be used.
Validator
implementations must have a zero-arguments
public constructor. In addition, if the Validator
class
wishes to have configuration property values saved and restored with
the view, the implementation must also implement StateHolder
.
If the class implementing
Validator
has a ResourceDependency
annotation, the action
described in ResourceDependency
must be taken when
EditableValueHolder.addValidator(javax.faces.validator.Validator)
is
called. If the class implementing Validator
has a ResourceDependencies
annotation, the
action described in ResourceDependencies
must be taken
when EditableValueHolder.addValidator(javax.faces.validator.Validator)
is called.
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
NOT_IN_RANGE_MESSAGE_ID
Deprecated.
|
Modifier and Type | Method and Description |
---|---|
void |
validate(FacesContext context,
UIComponent component,
T value)
|
static final java.lang.String NOT_IN_RANGE_MESSAGE_ID
DoubleRangeValidator.NOT_IN_RANGE_MESSAGE_ID
or
LongRangeValidator.NOT_IN_RANGE_MESSAGE_ID
instead.The message identifier of the FacesMessage
to be created if
the maximum or minimum value check fails, and both the maximum
and minimum values for this validator have been set. The message
format string for this message may optionally include a
{0}
placeholder, which will be replaced by the
configured minimum value, and a {1}
placeholder,
which will be replaced by the configured maximum value.
void validate(FacesContext context, UIComponent component, T value) throws ValidatorException
Perform the
correctness checks implemented by this Validator
against
the specified UIComponent
. If any violations are found,
a ValidatorException
will be thrown containing the FacesMessage
describing the failure.
For a validator to be fully compliant with Version 2 and later
of the specification, it must not fail validation on
null
or empty values unless it is specifically
intended to address null
or empty values. An
application-wide <context-param>
is provided
to allow validators designed for JSF 1.2 to work with JSF 2 and
later. The javax.faces.VALIDATE_EMPTY_FIELDS
<context-param>
must be set to
false
to enable this backwards compatibility
behavior.
context
- FacesContext for the request we are processingcomponent
- UIComponent we are checking for correctnessvalue
- the value to validateValidatorException
- if validation failsjava.lang.NullPointerException
- if context
or component
is null
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