How to enable a second-level cache in Hibernate?
2 answers
@casper To enable a second-level cache in Hibernate, you will need to do the following steps:
- Add the following dependencies to your project's classpath:
- hibernate-ehcache for Ehcache support
- hibernate-infinispan for Infinispan support
- Configure the second-level cache in your Hibernate configuration file (e.g., hibernate.cfg.xml). For example:
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<hibernate-configuration> <session-factory> <!-- Enable the second-level cache --> <property name="hibernate.cache.use_second_level_cache">true</property> <!-- Choose a cache provider --> <property name="hibernate.cache.region.factory_class"> org.hibernate.cache.ehcache.EhCacheRegionFactory </property> </session-factory> </hibernate-configuration> |
- Annotate the entities that you want to cache with @Cache and specify the cache region. For example:
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@Entity @Cache(usage = CacheConcurrencyStrategy.READ_WRITE, region = "employee") public class Employee { ... } |
- Optionally, you can configure the second-level cache settings in your ehcache.xml file or infinispan.xml file.
Note that the second-level cache is disabled by default in Hibernate. You need to enable it explicitly in the configuration. Also, keep in mind that the second-level cache is a shared cache that is used across all sessions, so you need to carefully design your cache invalidation strategy to avoid stale data.
@casper
Additionally, you may also need to configure the cache settings specific to the cache provider you are using. For example, if you are using Ehcache, you can specify the configuration in the ehcache.xml file. Here is an example of how to configure Ehcache:
- Create an ehcache.xml file in your project's classpath, for example:
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<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="http://www.ehcache.org/ehcache.xsd"
updateCheck="false">
<defaultCache maxEntriesLocalHeap="10000" eternal="false"
timeToIdleSeconds="120" timeToLiveSeconds="120" />
<cache name="employee"
maxEntriesLocalHeap="10000" eternal="false"
timeToIdleSeconds="120" timeToLiveSeconds="120">
<persistence strategy="none" />
</cache>
</ehcache>
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- Configure the cache provider class in your Hibernate configuration file:
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<hibernate-configuration>
<session-factory>
<!-- Enable the second-level cache -->
<property name="hibernate.cache.use_second_level_cache">true</property>
<!-- Choose a cache provider and specify the location of the ehcache.xml file -->
<property name="hibernate.cache.region.factory_class">
org.hibernate.cache.ehcache.EhCacheRegionFactory
</property>
<property name="net.sf.ehcache.configurationResourceName">ehcache.xml</property>
</session-factory>
</hibernate-configuration>
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With these configurations, Hibernate will enable the second-level cache and use the specified cache provider and cache settings to cache entities in your application.