JPA (5) uses second-level cache, and jpa uses second-level cache

JPA (5) uses second-level cache, and jpa uses second-level cache

Jpa caches are classified into level-1 caches and level-2 caches. level-1 caches are session-level, while level-2 caches are cross-session-level.

The second-level cache is used and Ehcache is used. The first step is to configure the second-level cache in the configuration file.

<shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode> 

Note:It is a second-level cache. Of course, you need to know what to cache and what jpa products to use (which I understand), so this configuration must be at the end,

<? Xml version = "1.0" encoding = "UTF-8"?> <Persistence version = "2.0" xmlns = "http://java.sun.com/xml/ns/persistence" xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi: schemaLocation = "http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> <persistence-unit name = "jpa-1" transaction-type = "RESOURCE_LOCAL"> <! -- Configure what ORM product to use --> <! -- Note: 1. the implemented ORM policy inherits javax. persistence. spi. persistenceProvide interface. 2. If there is only one JPA implementation product in the project, it is acceptable if it is not specified --> <provider> org. hibernate. ejb. hibernatePersistence </provider> <! -- Add a persistence class --> <class> com. hotusm. commom. entity. user </class> <class> com. hotusm. commom. entity. phone </class> <class> com. hotusm. commom. entity. firstLover </class> <class> com. hotusm. commom. entity. teacher </class> <class> com. hotusm. commom. entity. student </class> <class> com. hotusm. commom. entity. food </class> <! -- Add second-level cache policy ALL: So ALL object classes are cached NONE: So ALL objects are not cached ENABLE_SELECTIVE: the entity marked with @ Cacheable (true) will be cached DISABLE_SELECTIVE: in addition to the entity UNSPECIFIFD labeled @ Cacheable (true), the cache defaults. The default value of JPA is used, this depends on the specific implementation product of JPA --> <shared-cache-mode> ENABLE_SELECTIVE </shared-cache-mode> <properties> <property name = "javax. persistence. jdbc. driver "value =" com. mysql. jdbc. driver "/> <property name =" javax. persistence. jdbc. url "value =" jdbc: mysql: // jpa "/> <property name =" javax. persistence. jdbc. user "value =" root "/> <property name =" javax. persistence. jdbc. password "value =" 1234 "/> <! -- Configure the jpa implementation product --> <property name = "hibernate. show_ SQL "value =" true "/> <property name =" hibernate. hbm2ddl. auto "value =" update "/> <property name =" hibernate. format_ SQL "value =" true "/> <! -- Use level 2 Cache --> <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> </persistence-unit> </persistence>

In this way, you can configure @ Cacheable on the object class to specify whether to use the second-level cache,