hibernate二级缓存理解

Question

刚开始学习hibernate，并了解hibernate二级缓存。我创建了一个评论实体并尝试处理它。这是我的代码！

 @Entity
 @Table(name = "comment")
 @FilterDefs(value={@FilterDef(name="projectFilter",parameters=@ParamDef(name="projectID", type="java.lang.Long" )),   @FilterDef(name="issueFilter", parameters=@ParamDef( name="issueID", type="java.lang.Long" ) )})
 @Filters(value={@Filter(name = "projectFilter", condition = "project_id = :projectID"), 
    @Filter(name = "issueFilter", condition = "issue_id = :issueID")})
  @Cache(usage=CacheConcurrencyStrategy.READ_WRITE, region="comment")
  public class Comment {

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name = "id", unique = true, nullable = false, precision = 5, scale = 0 )
private long id;
@Column(name = "project_id", nullable = false)
private long projectId;
@Column(name = "issue_id", nullable = false)
private long issueId;
@Column(name = "author_id", nullable = false)
private long auhorId;
@Column(name = "author_name", nullable = false)
private String authorName;
@Column(name = "comment")
private String comment;
@Column(name = "created_date")
private Date createdDate;

我想根据项目或项目和问题获取用户评论。在DAO中，我基于projectid为cmets编写了如下函数。

   @Autowired
   private SessionFactory sessionFactory;
  ...
  @Override
  public List<Comment> getAllProjectComments(long projectId) {  
    Session session = getCurrentSession();
    Filter filter = session.enableFilter("projectFilter");
    filter.setParameter("projectID", projectId);
    return session.createQuery("from Comment").setCacheable(true).list();

}

下面是ehcahe.xml

    <?xml  version="1.0" encoding="UTF-8"?>
    <ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xsi:noNamespaceSchemaLocation="../config/ehcache.xsd" updateCheck="false">
    <diskStore path="java.io.tmpdir/hibernate-cache"/>

    <defaultCache maxElementsInMemory="500"
            eternal="false"
            timeToIdleSeconds="1200"
            timeToLiveSeconds="2400"
            overflowToDisk="false"
            maxElementsOnDisk="1000"
            diskPersistent="false"
            diskExpiryThreadIntervalSeconds="1200"
            memoryStoreEvictionPolicy="LRU"/>

    <cache  name="org.trackMyProject.entity.Comment"
   maxElementsInMemory="50"
   maxElementsOnDisk="500"
   eternal="false"
       timeToIdleSeconds="30"
       timeToLiveSeconds="120"
       overflowToDisk="true"
    />

我在表格中为 2 个投影添加了 500 cmets。

当控制器调用 DAO 方法以根据项目 id 获取 cmets 以及随后对该项目 id 的调用似乎与 2 级缓存完美配合，并且 DB 没有被命中。但是，如果我不断在 2 个 projectID 之间切换，那么每次 DB 都被击中，这是我不想要的。

谁能告诉我我犯了什么样的错误或需要做更多的配置。

提前致谢！！

编辑！

类路径：hibernate.cfg.xml

<property name="hibernateProperties">
    <props>
        <prop key="hibernate.dialect">${jdbc.dialect}</prop>
        <prop key="hibernate.show_sql">true</prop>
        <!-- <prop key="hibernate.cache.use_query_cache">true</prop> -->
        <prop key="hibernate.connection.release_mode">after_transaction</prop>
        <prop key="hibernate.bytecode.use_reflection_optimizer">true</prop>
        <prop key="hibernate.hbm2ddl.auto">update</prop>
        <prop key="hibernate.cache.provider_configuration_file_resource_path">ehcache.xml</prop>
        <prop key="hibernate.cache.use_second_level_cache">true</prop>
        <prop key="hibernate.cache.use_query_cache">true</prop>
        <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop>
        <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop>
    </props>
</property>
</bean>

Answer 1

您正在使用 createQuery，这意味着您需要查询级别缓存，请尝试添加：

<property name='hibernate.cache.use_query_cache'>true</property>