contains(cls, primaryKey) - JPA Cache's method

boolean contains(
  Class cls,
  Object primaryKey

Whether the cache contains data for the given entity.
cls - entity class
primaryKey - primary key
boolean indicating whether the entity is in the cache
JPA 2.0

This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
ObjectDB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.