JPA系列十：二级缓存

落日映苍穹つ 2022-02-09 11:13 273阅读 0赞

1、在persistence.xml中配置

<shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
    
    
     <properties>
    	<property name="hibernate.cache.use_second_level_cache" value="true"/>
    	<property name="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.EhCacheRegionFactory"/>
    	<property name="hibernate.cache.use_query_cache" value="true"/>
    </properties>

2、添加ehcache  
（1）、引入依赖

<dependency>
         <groupId>net.sf.ehcache</groupId>
         <artifactId>ehcache-core</artifactId>
         <version>2.4.3</version>
     </dependency>
      <dependency>
    	 <groupId>org.hibernate</groupId>
         <artifactId>hibernate-ehcache</artifactId>
         <version>4.2.4.Final</version>
     </dependency>

（2）、创建ehcache.xml

3、在实体类Customer添加注解@Cacheable

@Cacheable
    @Table(name="JPA_CUTOMERS")
    @Entity
    public class Customer {
    }

测试：

@Test
    public void testSecondLevelCache(){
    	Customer customer1 = entityManager.find(Customer.class, 6);
    	System.out.println(customer1);
    	transaction.commit();
    	entityManager.close();
    	entityManager = entityManagerFactory.createEntityManager();
    	transaction = entityManager.getTransaction();
    	transaction.begin();
    	Customer customer2 = entityManager.find(Customer.class, 6);
    	System.out.println(customer2);
    }

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