Package net.sourceforge.pmd.properties

Interface PropertyConstraint<T>

Type Parameters:

T - Type of value to handle

public interface PropertyConstraint<T>

Validates the value of a property.

Author:

Clément Fournier

Since:

6.10.0

See Also:

• PropertyBuilder.require(PropertyConstraint)

Method Summary

Modifier and Type	Method	Description
static <U> PropertyConstraint<U>	fromPredicate(Predicate<? super U> pred, String constraintDescription)	Builds a new validator from a predicate, and description.
static <U> PropertyConstraint<U>	fromPredicate(Predicate<? super U> pred, String constraintDescription, Map<String,String> xmlConstraint)	Builds a new constraint from a predicate, a description and xml attributes to serialize the constraint.
String	getConstraintDescription()	Returns a description of the constraint imposed by this validator on the values.
default Map<String,String>	getXmlConstraint()	Serializes this constraint as XML attributes, that are part of the property element of a rule definition.
default PropertyConstraint<Iterable<? extends T>>	toCollectionConstraint()	Returns a constraint that validates a collection of Ts by checking each component conforms to this validator.
default PropertyConstraint<Optional<? extends T>>	toOptionalConstraint()	Returns a constraint that validates an Optional<T> by checking that the value conforms to this constraint if it is non-empty.
void	validate(T value)	Checks that the value conforms to this constraint.

Method Details

validate

void validate(T value)

Checks that the value conforms to this constraint. Throws if that is not the case.

Parameters:

value - The value to validate

Throws:

ConstraintViolatedException - If this constraint is violated

getConstraintDescription

String getConstraintDescription()

Returns a description of the constraint imposed by this validator on the values. E.g. "Should be positive", or "Should be one of A | B | C."

This is used to generate documentation.

Returns:

A description of the constraint

getXmlConstraint

default Map<String,String> getXmlConstraint()

Serializes this constraint as XML attributes, that are part of the property element of a rule definition.

Note: This is only used for constraints, which can be defined in a rule definition in a ruleset (e.g. for XPath rules).

Returns:

a map with attribute name and attribute value, suitable to be used in XML.

See Also:

• SchemaConstants.PROPERTY_MIN
• SchemaConstants.PROPERTY_MAX

toOptionalConstraint

default PropertyConstraint<Optional<? extends T>> toOptionalConstraint()

Returns a constraint that validates an Optional<T> by checking that the value conforms to this constraint if it is non-empty.

toCollectionConstraint

default PropertyConstraint<Iterable<? extends T>> toCollectionConstraint()

Returns a constraint that validates a collection of Ts by checking each component conforms to this validator.

Returns:

A collection validator

fromPredicate

static <U> PropertyConstraint<U> fromPredicate(Predicate<? super U> pred,
 String constraintDescription)

Builds a new validator from a predicate, and description.

Type Parameters:

U - Type of value to validate

Parameters:

pred - The predicate. If it returns false on a value, then the value is deemed to have a problem

constraintDescription - Description of the constraint, see getConstraintDescription().

Returns:

A new validator

fromPredicate

static <U> PropertyConstraint<U> fromPredicate(Predicate<? super U> pred,
 String constraintDescription,
 Map<String,String> xmlConstraint)

Builds a new constraint from a predicate, a description and xml attributes to serialize the constraint.

See Also:

• fromPredicate(Predicate, String)