javax.validation.ConstraintValidator Maven / Gradle / Ivy
/*
* Bean Validation API
*
* License: Apache License, Version 2.0
* See the license.txt file in the root directory or .
*/
package javax.validation;
import java.lang.annotation.Annotation;
import javax.validation.constraintvalidation.SupportedValidationTarget;
/**
* Defines the logic to validate a given constraint {@code A}
* for a given object type {@code T}.
*
* Implementations must comply to the following restriction:
*
* - {@code T} must resolve to a non parameterized type
* - or generic parameters of {@code T} must be unbounded
* wildcard types
*
*
* The annotation {@link SupportedValidationTarget} can be put on a
* {@code ConstraintValidator} implementation to mark it as supporting
* cross-parameter constraints. Check out {@link SupportedValidationTarget}
* and {@link Constraint} for more information.
*
* @param the annotation type handled by an implementation
* @param the target type supported by an implementation
*
* @author Emmanuel Bernard
* @author Hardy Ferentschik
*/
public interface ConstraintValidator {
/**
* Initializes the validator in preparation for
* {@link #isValid(Object, ConstraintValidatorContext)} calls.
* The constraint annotation for a given constraint declaration
* is passed.
*
* This method is guaranteed to be called before any use of this instance for
* validation.
*
* The default implementation is a no-op.
*
* @param constraintAnnotation annotation instance for a given constraint declaration
*/
default void initialize(A constraintAnnotation) {
}
/**
* Implements the validation logic.
* The state of {@code value} must not be altered.
*
* This method can be accessed concurrently, thread-safety must be ensured
* by the implementation.
*
* @param value object to validate
* @param context context in which the constraint is evaluated
*
* @return {@code false} if {@code value} does not pass the constraint
*/
boolean isValid(T value, ConstraintValidatorContext context);
}