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

Question

How can I express literal true and literal false in JPA's Criteria API?

I'm looking for something like Predicate alwaysTrue = CriterialBuilder.DefaultLiterals.TRUE (analogous to java.lang.Boolean.TRUE).

Answer 1

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

Answer 2

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();