Question

我正在使用Hibernate 3.3.4.GA.在我们的hibernate.cfg.xml文件中，我们指定了......

    <property name="hibernate.cache.provider_class">net.sf.ehcache.hibernate.SingletonEhCacheProvider</property>
    <property name="hibernate.cache.use_query_cache">true</property>
    <property name="hibernate.cache.use_second_level_cache">true</property>
    <property name="hibernate.cache.provider_configuration">classpath:ehcache.xml</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.format_sql">true</property>
    <property name="hibernate.use_sql_comments">true</property>
    <property name="hibernate.generate_statistics">true</property>
    <property name="hibernate.cache.use_structured_entries">true</property>

但是对DB执行测试（来自JUnit）会导致错过计数为零，命中数为零，这完全令人困惑......

@Test
public void testCache() {
    final String cacheRegion = WebLead.class.getCanonicalName();
    final SecondLevelCacheStatistics settingsStatistics = sessionFactory.getStatistics().getSecondLevelCacheStatistics(cacheRegion);

    // Make first query.
    webLeadsDAO.getLeads(lead);
    System.out.println("miss count:" + settingsStatistics.getMissCount());
    System.out.println("hit count:" + settingsStatistics.getHitCount());

    // Make second query, expect this to hit cache.
    webLeadsDAO.getLeads(lead);
    System.out.println("after second query, hit count: " + settingsStatistics.getHitCount());
}

以下是我们用于检索结果的方法。任何错过计数和命中数的原因都是零？

@Entity
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
@Table(name="LEAD")
public WebLeads getLeads(WebLead webLead) {
    final Session session = sessionFactory.openSession();
    final Criteria crit = session.createCriteria(WebLead.class);
    crit.setCacheable(Boolean.TRUE);

    // Find webLeads matching input
    crit.add( Example.create(webLead) );
    // Make special exception for primary key since that isn't covered by Example.create
    if (webLead.getLEAD_ID() != null) { 
        crit.add(Restrictions.eq("LEAD_ID", webLead.getLEAD_ID()));
    }   // if

    @SuppressWarnings("unchecked")
    final List<WebLead> results = crit.list();
    final WebLeads webLeads = new WebLeads();
    webLeads.addAll( results );

    session.close();
    return webLeads;
}

显然，缓存未启用，但我无法弄清楚原因。 - 戴夫

Answer 1

请在此处查看我的答案，了解有效的二级缓存配置：

Second Level Cache Configuration

我希望它有所帮助。

<强>更新

试试这个：

Statistics stats = sessionFactory.getStatistics();
stats.setStatisticsEnabled(true);
SecondLevelCacheStatistics cacheStats = stats.getSecondLevelCacheStatistics(cacheRegion);

Answer 2

您正在使用Hibernate 3.3.4，但正在为cache.provider_class配置pre 3.3 Hibernate。

点击此链接了解详情：http://ehcache.org/documentation/user-guide/hibernate

Hibernate：无法启用二级缓存

2 个答案: