org.hibernate.validator.ap.util

Class ConstraintHelper

java.lang.Object

org.hibernate.validator.ap.util.ConstraintHelper

public class ConstraintHelper
extends Object

Helper class that deals with all constraint-related stuff, such as determining whether a given annotation represents a constraint annotation or whether a given annotation is allowed to be declared at a given element.

Author:

Gunnar Morling, Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConstraintHelper.AnnotationProcessorConstraintTarget The validation target of a constraint annotation.
static class	ConstraintHelper.AnnotationProcessorValidationTarget Defines the object on which a validation is targeted.
static class	ConstraintHelper.AnnotationType The type of an annotation with respect to the BV API.
static class	ConstraintHelper.ConstraintCheckResult Possible results of a constraint check as returned by checkConstraint(DeclaredType, TypeMirror).

Constructor Summary

Constructors

Constructor and Description
ConstraintHelper(Types typeUtils, AnnotationApiHelper annotationApiHelper)

Method Summary

Modifier and Type	Method and Description
ConstraintHelper.ConstraintCheckResult	checkConstraint(DeclaredType constraintAnnotationType, TypeMirror typeOfAnnotatedElement) Checks whether the given annotation type (which must be a constraint annotation type) may be specified at elements of the specified type.
ConstraintHelper.ConstraintCheckResult	checkCrossParameterTypes(DeclaredType constraintAnnotationType) Check that a constraint has at most one cross-parameter validator that resolves to Object or Object[].
ConstraintHelper.AnnotationType	getAnnotationType(AnnotationMirror annotationMirror) Returns the ConstraintHelper.AnnotationType of the given annotation.
List<AnnotationMirror>	getPartsOfMultiValuedConstraint(AnnotationMirror annotationMirror) Returns a list with the constraint annotations contained in the given array-valued annotation mirror.
Set<ConstraintHelper.AnnotationProcessorValidationTarget>	getSupportedValidationTargets(DeclaredType constraintAnnotationType) Returns the set of AnnotationProcessorValidationTarget supported by the given constraint annotation type.
boolean	isComposedConstraint(TypeElement element) Checks whether the given type element represents a composed constraint or not.
boolean	isConstraintAnnotation(Element element) Checks whether the given type element represents a constraint annotation or not.
ConstraintHelper.AnnotationProcessorValidationTarget	resolveValidationTarget(ExecutableElement element, AnnotationMirror annotation) Resolve the actual AnnotationProcessorValidationTarget of a constraint annotation, when applied to a method/constructor.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConstraintHelper

public ConstraintHelper(Types typeUtils,
                        AnnotationApiHelper annotationApiHelper)

Method Detail

isConstraintAnnotation

public boolean isConstraintAnnotation(Element element)

Checks whether the given type element represents a constraint annotation or not. That's the case, if the given element is annotated with the @Constraint meta-annotation (which is only allowed at annotation declarations).

Parameters:

element - The element of interest.

Returns:

True, if the given element is a constraint annotation type, false otherwise.

getAnnotationType

public ConstraintHelper.AnnotationType getAnnotationType(AnnotationMirror annotationMirror)

Returns the ConstraintHelper.AnnotationType of the given annotation.

Parameters:

annotationMirror - The annotation mirror of interest.

Returns:

The given mirror's annotation type.

getPartsOfMultiValuedConstraint

public List<AnnotationMirror> getPartsOfMultiValuedConstraint(AnnotationMirror annotationMirror)

Returns a list with the constraint annotations contained in the given array-valued annotation mirror.

Parameters:

annotationMirror - An array-valued annotation mirror (meaning it has an array-typed attribute with name "value").

Returns:

A list with the constraint annotations part of the given multi-valued constraint annotation. Will return an empty list if the given annotation is no multi-valued annotation or if no constraint annotations are contained within the given array-valued annotation.

checkConstraint

public ConstraintHelper.ConstraintCheckResult checkConstraint(DeclaredType constraintAnnotationType,
                                                              TypeMirror typeOfAnnotatedElement)

Checks whether the given annotation type (which must be a constraint annotation type) may be specified at elements of the specified type.

Parameters:

constraintAnnotationType - A constraint annotation type.

typeOfAnnotatedElement - A type which with an element is annotated.

Returns:

Whether the given constraint annotation may be specified at elements of the given type.

isComposedConstraint

public boolean isComposedConstraint(TypeElement element)

Checks whether the given type element represents a composed constraint or not.

Parameters:

element - The type element of interest. Must not be null.

Returns:

True if the given element represents a composed constraint, false otherwise.

resolveValidationTarget

public ConstraintHelper.AnnotationProcessorValidationTarget resolveValidationTarget(ExecutableElement element,
                                                                                    AnnotationMirror annotation)

Resolve the actual AnnotationProcessorValidationTarget of a constraint annotation, when applied to a method/constructor.

When the annotation supports multiple ConstraintHelper.AnnotationProcessorValidationTargets (i.e. it is both cross-parameter and generic), the actual target is resolved using the 'validationAppliesTo()' attribute of the annotation.

Parameters:

element - the method/constructor on which the annotation is applied

annotation - the constraint annotation

Returns:

the resolved AnnotationProcessorValidationTarget, null if the target cannot be inferred

getSupportedValidationTargets

public Set<ConstraintHelper.AnnotationProcessorValidationTarget> getSupportedValidationTargets(DeclaredType constraintAnnotationType)

Returns the set of AnnotationProcessorValidationTarget supported by the given constraint annotation type.

A constraint annotation can support ConstraintHelper.AnnotationProcessorValidationTarget.ANNOTATED_ELEMENT, ConstraintHelper.AnnotationProcessorValidationTarget.PARAMETERS or both.

Parameters:

constraintAnnotationType - the constraint annotation type

Returns:

the set of supported AnnotationProcessorValidationTargets

checkCrossParameterTypes

public ConstraintHelper.ConstraintCheckResult checkCrossParameterTypes(DeclaredType constraintAnnotationType)

Check that a constraint has at most one cross-parameter validator that resolves to Object or Object[].

Parameters:

constraintAnnotationType - the constraint type

Returns:

ConstraintCheckResult#MULTIPLE_VALIDATORS_FOUND if the constraint has more than one cross-parameter validator, ConstraintCheckResult#DISALLOWED if the constraint has one cross-parameter validator with a wrong generic type, ConstraintCheckResult#ALLOWED otherwise