Can't get Eclipselink level 2 cache to work

问题

I have a minimal web app that you can download here (6Kb): http://www.mediafire.com/?6vo1tc141t65r1g

the relevant config is :

-eclipselink 2.3.2

-server is tomee 1.0 (but glassfish 3.1 is the same)

When I hit the page and press F5 to refresh repeatedly :

http://localhost:8080/testCache/jsf/test.xhtml

I see several lines like that in the console

[EL Fine]: 2012-08-29 19:01:30.821--ServerSession(32981564)--Connection(27242067)--Thread(Thread[http-bio-8080-exec-12,5,main])--SELECT id, tasktype FROM tasktype

And by running a sniffer I see that SQL requests are always sent to the server. I though the level 2 cache of Eclipselink would return the results (5 rows in a table) without querying the db. So what's wrong, how do I activate the cache ?

Some extracts from the files

persistence.xml :

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
  <persistence-unit name="xxxPU" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>microsoft</jta-data-source>
    <properties>

        <property name="eclipselink.logging.level" value="FINE"/>
      <property name="eclipselink.logging.parameters" value="true"/>

    </properties>
  </persistence-unit>
</persistence>

the EJB performing the query

/**
 * Some useless class required to use JTA transactions
 * 
 * @author Administrator
 * 
 */
@Stateless
public class Facade {
    @PersistenceContext(unitName = "xxxPU")
    private EntityManager em;


    public List findAll(Class entityClass) {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        cq.select(cq.from(entityClass));
        return em.createQuery(cq).getResultList();
    }

    public EntityManager getEntityManager() {
        return em;

    }

}

the entity bean :

@Entity
@Table(name = "tasktype")

public class TaskType {

    @Id

    @Column(name = "id")
    private Integer id;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 10)
    @Column(name = "tasktype")
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

}

回答1:

The L2 shared cache, caches objects by there Id. The find() operation, and queries by Id will obtain cache hits, other queries will not. The resulting objects will still be resolved with the cache, so you will not encure any additional queries for relationships once the objects are cached.

You can enable caching on a query, or (in 2.4) you can index non-Id fields, or query in-memory.

See, http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Caching

http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Caching/Query_Cache

http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Caching/Query_Options

来源：https://stackoverflow.com/questions/12177750/cant-get-eclipselink-level-2-cache-to-work

标签

java

caching

jpa

eclipselink