Interface PredicateSpecification<T>

Type Parameters:

T - the type of the From target to which the specification is applied.

All Superinterfaces:

Serializable

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface PredicateSpecification<T>
extends Serializable

Specification in the sense of Domain Driven Design.

Specifications can be composed into higher order functions from other specifications using and(PredicateSpecification), or(PredicateSpecification) or factory methods such as allOf(Iterable) with reduced type interference of the query source type.

PredicateSpecifications are building blocks for composition and do not express their type opinion towards a specific entity source or join source type for improved reuse.

Composition considers whether one or more specifications contribute to the overall predicate by returning a Predicate or null. Specifications returning null, such as unrestricted(), are considered to not contribute to the overall predicate, and their result is not considered in the final predicate.

Since:

4.0

Author:

Mark Paluch, Peter Aisher

Method Summary

Modifier and Type	Method	Description
static <T> PredicateSpecification<T>	allOf(Iterable<PredicateSpecification<T>> specifications)	Applies an AND operation to all the given PredicateSpecifications.
static <T> PredicateSpecification<T>	allOf(PredicateSpecification<T>... specifications)	Applies an AND operation to all the given PredicateSpecifications.
default PredicateSpecification<T>	and(PredicateSpecification<T> other)	ANDs the given PredicateSpecification to the current one.
static <T> PredicateSpecification<T>	anyOf(Iterable<PredicateSpecification<T>> specifications)	Applies an OR operation to all the given PredicateSpecifications.
static <T> PredicateSpecification<T>	anyOf(PredicateSpecification<T>... specifications)	Applies an OR operation to all the given PredicateSpecifications.
static <T> PredicateSpecification<T>	not(PredicateSpecification<T> spec)	Negates the given PredicateSpecification.
default PredicateSpecification<T>	or(PredicateSpecification<T> other)	ORs the given specification to the current one.
@Nullable jakarta.persistence.criteria.Predicate	toPredicate(jakarta.persistence.criteria.From<?,T> from, jakarta.persistence.criteria.CriteriaBuilder criteriaBuilder)	Creates a WHERE clause for a query of the referenced entity in form of a Predicate for the given From and CriteriaBuilder.
static <T> PredicateSpecification<T>	unrestricted()	Simple static factory method to create a specification which does not participate in matching.
static <T> PredicateSpecification<T>	where(PredicateSpecification<T> spec)	Simple static factory method to add some syntactic sugar around a PredicateSpecification.

Method Details

unrestricted

static <T> PredicateSpecification<T> unrestricted()

Simple static factory method to create a specification which does not participate in matching. The specification returned is null-like, and is elided in all operations.

unrestricted().and(other) // consider only `other`
unrestricted().or(other) // consider only `other`
not(unrestricted()) // equivalent to `unrestricted()`

Type Parameters:

T - the type of the From the resulting PredicateSpecification operates on.

Returns:

guaranteed to be not null.

where

static <T> PredicateSpecification<T> where(PredicateSpecification<T> spec)

Simple static factory method to add some syntactic sugar around a PredicateSpecification.

Type Parameters:

T - the type of the From the resulting PredicateSpecification operates on.

Parameters:

spec - must not be null.

Returns:

guaranteed to be not null.

Since:

2.0

and

@Contract("_ -> new")
@CheckReturnValue
default PredicateSpecification<T> and(PredicateSpecification<T> other)

ANDs the given PredicateSpecification to the current one.

Parameters:

other - the other PredicateSpecification.

Returns:

the conjunction of the specifications.

or

@Contract("_ -> new")
@CheckReturnValue
default PredicateSpecification<T> or(PredicateSpecification<T> other)

ORs the given specification to the current one.

Parameters:

other - the other PredicateSpecification.

Returns:

the disjunction of the specifications.

not

static <T> PredicateSpecification<T> not(PredicateSpecification<T> spec)

Negates the given PredicateSpecification.

Type Parameters:

T - the type of the From the resulting PredicateSpecification operates on.

Parameters:

spec - can be null.

Returns:

guaranteed to be not null.

allOf

@SafeVarargs
static <T> PredicateSpecification<T> allOf(PredicateSpecification<T>... specifications)

Applies an AND operation to all the given PredicateSpecifications. If specifications is empty, the resulting PredicateSpecification will be unrestricted() applying to all objects.

Parameters:

specifications - the PredicateSpecifications to compose.

Returns:

the conjunction of the specifications.

See Also:

• allOf(Iterable)
• and(PredicateSpecification)

allOf

static <T> PredicateSpecification<T> allOf(Iterable<PredicateSpecification<T>> specifications)

Applies an AND operation to all the given PredicateSpecifications. If specifications is empty, the resulting PredicateSpecification will be unrestricted() applying to all objects.

Parameters:

specifications - the PredicateSpecifications to compose.

Returns:

the conjunction of the specifications.

See Also:

• and(PredicateSpecification)
• allOf(PredicateSpecification[])

anyOf

@SafeVarargs
static <T> PredicateSpecification<T> anyOf(PredicateSpecification<T>... specifications)

Applies an OR operation to all the given PredicateSpecifications. If specifications is empty, the resulting PredicateSpecification will be unrestricted() applying to all objects.

Parameters:

specifications - the PredicateSpecifications to compose.

Returns:

the disjunction of the specifications.

See Also:

• or(PredicateSpecification)
• anyOf(Iterable)

anyOf

static <T> PredicateSpecification<T> anyOf(Iterable<PredicateSpecification<T>> specifications)

Applies an OR operation to all the given PredicateSpecifications. If specifications is empty, the resulting PredicateSpecification will be unrestricted() applying to all objects.

Parameters:

specifications - the PredicateSpecifications to compose.

Returns:

the disjunction of the specifications.

See Also:

• or(PredicateSpecification)
• anyOf(PredicateSpecification[])

toPredicate

@Nullable jakarta.persistence.criteria.Predicate toPredicate(jakarta.persistence.criteria.From<?,T> from,
 jakarta.persistence.criteria.CriteriaBuilder criteriaBuilder)

Creates a WHERE clause for a query of the referenced entity in form of a Predicate for the given From and CriteriaBuilder.

Parameters:

from - must not be null.

criteriaBuilder - must not be null.

Returns:

a Predicate, may be null.