二级缓存在 Hibernate 中没有激活？

Question

我正在研究 Hibernate 中的 Second Hibernate Cache。我有一个问题，我花更多的时间去探索，但没有。

• 我使用Oracle，通过注解创建表。

hibernate.cfg.xml：

<session-factory>
    <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
    <property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:quan</property>
    <property name="connection.username">system</property>
    <property name="connection.password">123456</property>

    <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>

     <!-- Enable Second Level Cache -->
    <property name="hibernate.cache.use_second_level_cache">true</property>
    <property name="net.sf.ehcache.configurationResourceName">ehcache.xml</property>
    <property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</property>


    <property name="show_sql">true</property>
    <property name="format_sql">true</property>
    <property name="hbm2ddl.auto">update</property>
    <mapping class="com.javamakeuse.poc.pojo.Employee"/>

</session-factory>

主类：

Transaction t=null;

        t=s.beginTransaction();
        Employee e=(Employee)s.get(Employee.class, new Integer(1));
        if(e!=null){
        System.out.print("ID :"+e.getEmpid());
        System.out.print(", Name :"+e.getEmpname());
        System.out.print(", Phone :"+e.getEmpmobile());
        System.out.println("Salary :"+e.getEmpsalary());
        }else{
            System.out.println("No records:!!");
        }

        //// second time loading same entity from the first level cache

        e=(Employee)s.get(Employee.class, new Integer(1));
        if(e!=null){
        System.out.print("ID :"+e.getEmpid());
        System.out.print(", Name :"+e.getEmpname());
        System.out.print(", Phone :"+e.getEmpmobile());
        System.out.println("Salary :"+e.getEmpsalary());
        }else{
            System.out.println("No records:!!");
        }

        // remove Cache
        s.evict(e);
        // Going to print Employee*** from Second level Cache
        // Why i have a new query???????????????????

         e=(Employee)s.get(Employee.class, new Integer(1));
        if(e!=null){
        System.out.print("ID :"+e.getEmpid());
        System.out.print(", Name :"+e.getEmpname());
        System.out.print(", Phone :"+e.getEmpmobile());
        System.out.println("Salary :"+e.getEmpsalary());
        }else{
            System.out.println("No records:!!");
        }

        t.commit();

ehcache.xml

<ehcache>
<defaultCache maxEntriesLocalHeap="4000" eternal="false"
    timeToIdleSeconds="60" timeToLiveSeconds="120" diskSpoolBufferSizeMB="20"
    maxEntriesLocalDisk="10000000" diskExpiryThreadIntervalSeconds="120"
    memoryStoreEvictionPolicy="LRU" statistics="true">
    <persistence strategy="localTempSwap" />
</defaultCache>

<cache name="country" maxEntriesLocalHeap="4000" eternal="false"
    timeToIdleSeconds="5" timeToLiveSeconds="10">
    <persistence strategy="localTempSwap" />
</cache>

<cache name="org.hibernate.cache.spi.UpdateTimestampsCache"
    maxEntriesLocalHeap="5000" eternal="true">
    <persistence strategy="localTempSwap" />
</cache>

控制台输出

ID :1Hibernate: 
select
    employee0_.empid as empid1_0_0_,
    employee0_.empmobile as empmobile2_0_0_,
    employee0_.empname as empname3_0_0_,
    employee0_.empsalary as empsalary4_0_0_ 
from
    employee2 employee0_ 
where
    employee0_.empid=?
Name :Nguyen VQ, Phone :948380166Salary :6.2
ID :1, Name :Nguyen VQ, Phone :948380166Salary :6.2
ID :1Hibernate: 
select
    employee0_.empid as empid1_0_0_,
    employee0_.empmobile as empmobile2_0_0_,
    employee0_.empname as empname3_0_0_,
    employee0_.empsalary as empsalary4_0_0_ 
from
    employee2 employee0_ 
where
    employee0_.empid=?
Name :Nguyen VQ, Phone :948380166Salary :6.2
ID4: 1,Name4 :Nguyen VQ,Mobile: 948380166, Salary: 6.2

当我通过 s.evict(e) 删除 e 时；然后是 SessionFactory，但它不工作（它创建新查询）

Answer 1

二级配置似乎设置正确。我怀疑的一件事是@Cache 属性。您是否使用 @Cache 注释在 Employee 对象上启用了 CacheConcurrencyStrategy。

@Cache(usage=CacheConcurrencyStrategy.READ_WRITE | NONSTRICT_READ_WRITE | TRANSACTIONAL)