剛開始學習hibernate,並瞭解休眠二級緩存。我創建了一個評論實體並嘗試着去實現它。這是我的代碼!休眠二級緩存瞭解
@Entity
@Table(name = "comment")
@FilterDefs(value={@FilterDef(name="projectFilter",[email protected](name="projectID", type="java.lang.Long")), @FilterDef(name="issueFilter", [email protected](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;
我想根據項目或項目和問題獲取用戶評論。在DAO中,我寫了以下基於projectid的評論函數。
@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();
}
和ehcahe.xml低於
<?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"
/>
我已經添加在表500個徵求意見2個projectids。
當控制器調用DAO方法獲取基於項目ID的註釋以及隨後對該項目ID的調用似乎與二級緩存完美協作並且數據庫沒有被擊中時。但是如果我不斷地在兩個projectID之間切換,那麼每次DB被擊中時,我都不想要。
有人可以告訴我我做了什麼樣的錯誤或需要做更多的配置。
在此先感謝!
編輯!
類路徑:hibernate.cfg.xml的
<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>
可能重複[什麼是休眠的第一和第二級緩存?](http://stackoverflow.com/questions/337072/what-is-first-and-second-level-caching-in-hibernate) – NimChimpsky