Question

我正在尝试使用ehcache实现来获得二级hibernate缓存。

我确定这是我正在做的一个明显的noob错误，但我看不出它是什么！

要测试我的缓存，我正在执行以下操作：

创建对象并保存。我在事务中得到了一次，我可以看到我在没有db命中的情况下返回对象，这只是hibernate的第一级缓存做的事情。

然后我提交交易并开始新的会话。

这次，当我'得到'对象时，我可以在调试中看到来自ehcache的缓存未命中。自从我将它保存在上一个事务中之后，我原本期望该对象在缓存中吗？

这是我的代码：

  Session session = getSession();   
  session.beginTransaction();

  Test1 test1a = new Test1();
  test1a.setId(5);
  test1a.setName("Test 1");
  test1a.setValue(10);
  // Touch it
  session.save(test1a);

  // Now get it
  Test1 test1b = (Test1)session.get(Test1.class, 5);

  // Within a transaction, the session caches it - no db hit
  System.out.println("GOT object with value "+test1b.getValue());

  session.getTransaction().commit();

  System.out.println("Between sessions");

  session = getSession();
  session.beginTransaction();

  test1b = (Test1)session.get(Test1.class, 5);

  System.out.println("GOT object with value "+test1b.getValue());

  session.getTransaction().commit();

这是我的hibernate.cfg.xml的相关部分

<property name="cache.provider_class">org.hibernate.cache.EhCacheProvider</property>

我的ehcache.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="http://ehcache.sf.net/ehcache.xsd"> 
    <cache name="com.play.hibernate1.Test1" maxElementsInMemory="1000" eternal="false"     timeToLiveSeconds="600" overflowToDisk="false"/>
    <defaultCache maxElementsInMemory="10000" eternal="false"
overflowToDisk="true" timeToIdleSeconds="10" timeToLiveSeconds="20" diskPersistent="true" />
    </ehcache>

我的注释

@Entity
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class Test1 {

调试日志

11:21:03,474 DEBUG CacheManager:239 - Configuring ehcache from classpath.
11:21:03,479 DEBUG ConfigurationFactory:122 - Configuring ehcache from ehcache.xml found in the classpath: file:/Users/bw/Documents/workspace/hibernate1/target/classes/ehcache.xml
11:21:03,479 DEBUG ConfigurationFactory:87 - Configuring ehcache from URL: file:/Users/brucewood/Documents/workspace/hibernate1/target/classes/ehcache.xml
11:21:03,480 DEBUG ConfigurationFactory:139 - Configuring ehcache from InputStream
11:21:03,485 DEBUG BeanHandler:213 - Ignoring ehcache attribute xmlns:xsi
11:21:03,485 DEBUG BeanHandler:213 - Ignoring ehcache attribute xsi:noNamespaceSchemaLocation
11:21:03,517 DEBUG ConfigurationHelper:208 - No CacheManagerEventListenerFactory class specified. Skipping...
11:21:03,518 DEBUG ConfigurationHelper:183 - No CachePeerListenerFactoryConfiguration specified. Not configuring a CacheManagerPeerListener.
11:21:03,518 DEBUG ConfigurationHelper:159 - No CachePeerProviderFactoryConfiguration specified. Not configuring a CacheManagerPeerProvider.
11:21:03,525 DEBUG ConfigurationHelper:135 - No BootstrapCacheLoaderFactory class specified. Skipping...
11:21:03,526 DEBUG ConfigurationHelper:135 - No BootstrapCacheLoaderFactory class specified. Skipping...
11:21:03,532 DEBUG MemoryStore:73 - Initialized net.sf.ehcache.store.LruMemoryStore for com.play.hibernate1.Test1
11:21:03,533 DEBUG LruMemoryStore:71 - com.play.hibernate1.Test1 Cache: Using SpoolingLinkedHashMap implementation
11:21:03,533 DEBUG Cache:429 - Initialised cache: com.play.hibernate1.Test1
1528 [Finalizer] INFO org.hibernate.connection.DriverManagerConnectionProvider - cleaning up connection pool: jdbc:mysql://localhost:3306/play
1668 [main] INFO org.hibernate.impl.SessionFactoryObjectFactory - Not binding factory to JNDI, no JNDI name configured
GOT object with value 10
Hibernate: 
    /* insert com.play.hibernate1.Test1
        */ insert 
        into
            Test1
            (name, value, id) 
        values
            (?, ?, ?)
1274984463818|1|1|batch|/* insert com.play.hibernate1.Test1 */ insert into Test1 (name, value, id) values (?, ?, ?)|/* insert com.play.hibernate1.Test1 */ insert into Test1 (name, value, id) values ('Test 1', 10, 5)
1274984463820|1|1|statement|/* insert com.play.hibernate1.Test1 */ insert into Test1 (name, value, id) values (?, ?, ?)|/* insert com.play.hibernate1.Test1 */ insert into Test1 (name, value, id) values ('Test 1', 10, 5)
1274984463821|1|1|commit||
Between sessions
11:21:03,823 DEBUG EhCache:68 - key: com.play.hibernate1.Test1#5
11:21:03,823 DEBUG MemoryStore:138 - com.play.hibernate1.Test1Cache: com.play.hibernate1.Test1MemoryStore miss for com.play.hibernate1.Test1#5
11:21:03,823 DEBUG Cache:661 - com.play.hibernate1.Test1 cache - Miss
11:21:03,824 DEBUG EhCache:77 - Element for com.play.hibernate1.Test1#5 is null
Hibernate: 
    /* load com.play.hibernate1.Test1 */ select
        test1x0_.id as id0_0_,
        test1x0_.name as name0_0_,
        test1x0_.value as value0_0_ 
    from
        Test1 test1x0_ 
    where
        test1x0_.id=?
1274984463829|4|1|statement|/* load com.play.hibernate1.Test1 */ select test1x0_.id as id0_0_, test1x0_.name as name0_0_, test1x0_.value as value0_0_ from Test1 test1x0_ where test1x0_.id=?|/* load com.play.hibernate1.Test1 */ select test1x0_.id as id0_0_, test1x0_.name as name0_0_, test1x0_.value as value0_0_ from Test1 test1x0_ where test1x0_.id=5
1274984463831|-1||resultset|/* load com.play.hibernate1.Test1 */ select test1x0_.id as id0_0_, test1x0_.name as name0_0_, test1x0_.value as value0_0_ from Test1 test1x0_ where test1x0_.id=5|name0_0_ = Test 1, value0_0_ = 10
GOT object with value 10
1274984463834|0|1|commit||

感谢您的帮助！

Answer 1

问题在于我使用的是NONSTRICT_READ_WRITE。它似乎符合文档中这个解释的说法：

如果申请只是偶尔需要更新数据（即如果是的话）两个人极不可能交易会尝试更新相同的项目同时），严格不需要事务隔离，非严格读写缓存可能是适当。如果在a中使用缓存 JTA环境，必须指定 hibernate.transaction.manager_lookup_class属性。在其他环境中，你应该确保交易在Session.close（）或时完成调用Session.disconnect（）。

但实际上它似乎没有将保存的对象添加到缓存中。文档在这里有点薄，IMO。使用Hibernate对Java Persistence中的缓存选项有一个更好的处理方法，尽管对于数据实际发生的具体解释仍然有点薄弱。反正..

我将缓存选项更改为READ_WRITE，现在它按预期工作。

另请注意，第一次将对象添加到缓存时，ehcache调试中会出现“缓存未命中”。据推测，它在其缓存中查找，发现对象不存在，记录未命中，然后添加对象。在那之后，你得到'命中'。

Answer 2

还要警惕org.hibernate.action.internal.BulkOperationCleanupAction中的错误。＃affectededntity见两者中的讨论

https://forum.hibernate.org/viewtopic.php?f=1&t=998970

和

https://hibernate.atlassian.net/browse/HHH-4035

休眠二级ehcache小姐

2 个答案: