hibernate 二级缓存的问题~~~~~~~~~~~~~

惊变二十八天 2010-03-18 11:14:30

我想用二级缓存，有点问题搞不明白求教中
Person.hbm.xml



<hibernate-mapping package="hiber.domain">



	<class name="Person"  >

		<cache usage="read-write"/>

		<id name="id">

			<generator class="increment"/>

		</id>

		<property name="name" not-null="true"/>

	</class>

</hibernate-mapping>

hibernate.hbm.xml



<property name="hibernate.cache.use_second_level_cache">true</property>

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

<property name="hibernate.generate_statistics">true</property>

ehcache.xml



<cache name="hiber.domain.Person"

        maxElementsInMemory="1000"

        eternal="true"

        timeToIdleSeconds="0"

        timeToLiveSeconds="0"

        overflowToDisk="false"

        />

测试类



public class One2One {



	public static void main(String[] args) {



		addPersonAndIdCard2();

		check();

	}

	public static void addPersonAndIdCard2() {



		Session s= HiberUtil.getSession();

		Transaction t = s.beginTransaction();

		try{

			Person person = new Person();

			person.setName("sunyaozong");

			

			s.save(person);		

			t.commit();

		}catch(HibernateException e){

			if(t!=null){

				t.rollback();

			}

			throw e;

		}finally{

			if(s!=null){

				

				s.close();

			}

		}

	}



	public  static  void check(){

		Session s= null;

		Transaction t =null;

		try{

			s= HiberUtil.getSession();

			t = s.beginTransaction();

			



			//s.getSessionFactory().evict(Person.class); //语句（1）

			Person p1 =(Person)s.get(Person.class, 1);//语句（2）

			System.out.println(""+p1.getName());

			s.clear();					//语句（3）

			Person p2 =(Person)s.get(Person.class, 1);	//语句（4）	

			System.out.println(""+p2.getName());

		}catch(HibernateException e){

			if(t!=null){

				t.rollback();

			}

			throw e;

		}finally{

			if(s!=null){

				s.close();

			}

		}

		try{

			s= HiberUtil.getSession();

			t = s.beginTransaction();

			s.getSessionFactory().evict(Person.class);//语句（5）

			Person p2 =(Person)s.get(Person.class, 1);	//语句（6）	

			System.out.println(""+p2.getName());

		}catch(HibernateException e){

			if(t!=null){

				t.rollback();

			}

			throw e;

		}finally{

			if(s!=null){

				s.close();

			}

		}

		Statistics st =s.getSessionFactory().getStatistics();

		System.out.println(st);

		System.out.println("put:"+st.getSecondLevelCachePutCount());

		System.out.println("hit:"+st.getSecondLevelCacheHitCount());

		System.out.println("miss:"+st.getSecondLevelCacheMissCount());	

	}

}

测试结果



Hibernate: select idcard0_.person_id as person1_3_0_, idcard0_.name as name3_0_ from idcard idcard0_ where idcard0_.person_id=?

sunyaozong

Hibernate: select idcard0_.person_id as person1_3_0_, idcard0_.name as name3_0_ from idcard idcard0_ where idcard0_.person_id=?

sunyaozong

Hibernate: select person0_.id as id2_1_, person0_.name as name2_1_, idcard1_.person_id as person1_3_0_, idcard1_.name as name3_0_ from Person person0_ left outer join idcard idcard1_ on person0_.id=idcard1_.person_id where person0_.id=?

sunyaozong

Statistics[start time=1268924734687,sessions opened=3,sessions closed=3,transactions=1,successful transactions=1,optimistic lock failures=0,flushes=1,connections obtained=3,statements prepared=5,statements closed=5,second level cache puts=2,second level cache hits=2,second level cache misses=1,entities loaded=1,entities updated=0,entities inserted=1,entities deleted=0,entities fetched=2,collections loaded=0,collections updated=0,collections removed=0,collections recreated=0,collections fetched=0,queries executed to database=0,query cache puts=0,query cache hits=0,query cache misses=0,max query time=0]

put:2

hit:2

miss:1