Interrogating the JPA L2 cache

JPACacheOps.java

@Stateless
public class JPACacheOps{
  @persistenceContext("emp_PU")
  EntityManager em;
  
  public void testL2Cache(String id){
    String id = "007";
    String anotherID = "42";
    
    em.find(Employee.class, id);
    em.find(Employee.class, id);
    //both '007' and '42' are in L2 cache
    
    String orgID = "org123";
    em.find(Org.class, orgID); //'org123' is now in L2 cache
    
    Cache sharedL2Cache = em.getEntityManagerFactory().getCache();
    
    sharedL2Cache.contains(Employee.class , id); //returns true
    sharedL2Cache.evict(Employee.class, id); //'007' removed from shared cache
    sharedL2Cache.contains(Employee.class, id); //returns false
    
    sharedL2Cache.evict(Employee.class); //ALL 'Employee' entities removed
    sharedL2Cache.contains(Employee.class, anotherID); //returns false
    
    sharedL2Cache.contains(Org.class , orgID); //returns true
    sharedL2Cache.evictAll(); //ALL entities removed
    sharedL2Cache.contains(Ord.class, orgID); //returns false
  }
}