OpenJpa request caching does not update if null

Question

I ran into some problem in OpenJpa second level caching. Most often, caching works, but in one specific case it does not work. Here is the scenario when it does not work, When your code returns a null value, it stores it in the cache, and then it never clears that value. Although it clears the values ​​only when the query returns a value.

Here is the code I wrote to get the value from the database,

List<PartnerapiworkflowEntity> partnerapiworkflowEntityList = null;
        try {
            partnerapiworkflowEntityList = entityManager.createQuery("select p from someentity p where p.id = :Id and p.name = :name and " +
                    "p.code = :Code and p.operationname = :operationName")
                    .setParameter("Id", Id)
                    .setParameter("name", name)
                    .setParameter("code", Code)
                    .setParameter("operationName", operationName).getResultList();//.getSingleResult();
            if(partnerapiworkflowEntityList != null && partnerapiworkflowEntityList.size() > 0){
                return Boolean.TRUE;
            }
        } catch (NoResultException ne) {
            logger.severe("some logging info.");
        }
        finally {
//            entityManager.detach(partnerapiworkflowEntity);
        }

And here is the code that updates the cache.

try{
    entityManager.flush();
    entityManager.clear();
    entityManager.getEntityManagerFactory().getCache().evictAll();
    //((JpaEntityManager)entityManager.getDelegate()).getServerSession().getIdentityMapAccessor().invalidateAll();
    entityManager.flush();

} catch (Exception e){
    throw e;
}

And this is the persistence.xml code

<property name="openjpa.jdbc.DBDictionary" value="mysql"/>
<property name="openjpa.DataCache" value="true(EnableStatistics=true, CacheSize=10000, SoftReferenceSize=0, EvictionSchedule='+10')"/>
<property name="openjpa.QueryCache" value="true(EvictPolicy='timestamp')"/>
<!--<property name="openjpa.jdbc.QuerySQLCache" value="true(EnableStatistics=true)"/>-->
<property name="javax.persistence.sharedCache.mode" value="ENABLE_SELECTIVE"/>

<property name="openjpa.Instrumentation" value="jmx(Instrument='DataCache,QueryCache,QuerySQLCache')"/>
<property name="openjpa.MetaDataRepository" value="Preload=true"/>

<property name="openjpa.Log" value="SQL=Trace" />
<property name="openjpa.ConnectionFactoryProperties" value="PrintParameters=true" />

Everything works fine when the query always returns a value. The problem starts when null is returned. It is then first stored in the cache, and then it is never updated.

I am using OpenJpa2 and Hibernate.

Answer 1

OpenJPA 2.2.2. , , L2 (https://issues.apache.org/jira/browse/OPENJPA-2285)

https://issues.apache.org/jira/browse/OPENJPA-2522

---

:

. .

( ), openjpa.QueryCache false:

<property name="openjpa.QueryCache" value="false"/>

2. sql false

   • :

     <property name="openjpa.jdbc.QuerySQLCache" value="com.mycompany.MyCustomCache"/>

   • :

     <property name="openjpa.jdbc.QuerySQLCache" value="false"/>

   • :

     <property name="openjpa.jdbc.QuerySQLCache" value="all"/>

   ---

   3. JPA - L2 Cache

. .

, , . NullPointerException . , OpenJPA .: D

---

4. SQL JPQL.

SQL- , SPI OpenJPA EntityManager:

OpenJPAEntityManagerSPI.setQuerySQLCache(boolean) 

5. openjpa.jdbc.QuerySQLCache JPQL, .

   <property name="openjpa.jdbc.QuerySQLCache" value="true(excludes='select c from Company c;select d from Department d')"/>

JPQL select c from Company c select d from Department d.

:

, . , JPA , , , . , , , , . , , , . , , , .

IBM:

L2 , L2. . L2 - , . L2 .

:

JPA 2.4.0

Answer 2

, ? , , ... , null . ?

EDIT:

<property name="openjpa.QueryCache" value="false"/>

. .

- NULL ? - ?