JPA Criteria API: how to express literal true and literal false?

CriteriaBuilder#conjunction() returns a TRUE predicate.

CriteriaBuilder#disjunction() returns a FALSE predicate.

/**
 * Create a conjunction (with zero conjuncts).
 * A conjunction with zero conjuncts is true.
 *
 * @return and predicate
 */
Predicate conjunction();

/**
 * Create a disjunction (with zero disjuncts).
 * A disjunction with zero disjuncts is false.
 *
 * @return or predicate
 */
Predicate disjunction();

To get an always true Predicate instance, use criteriaBuilder.and().
To get an always false Predicate instance, use criteriaBuilder.or().

Although the other answers solve the problem, I think they don't show the intention of the code, which should be "an always true predicate".

Personally I think the approach below is more clear, although a bit longer.

Always true

criteriaBuilder.isTrue(criteriaBuilder.literal(true));

Always false

criteriaBuilder.isFalse(criteriaBuilder.literal(true));