[mybatis]缓存_二级缓存使用细节

二级缓存

开启全局二级缓存

 <setting name="cacheEnabled" value="true"/>

去mapper.xml中配置使用二级缓存

<cache></cache>

<cache eviction="FIFO" flushInterval="60000" readOnly="false" size="1024" ></cache>

cache中的配置

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type = “”：指定自定义缓存的全类名；实现Cache接口即可；

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我们的POJO需要实现序列化接口

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测试

@Testpublic void testSecondLevelCache() throws IOException {SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();SqlSession sqlSession = sqlSessionFactory.openSession();SqlSession sqlSession1 =   sqlSessionFactory.openSession();try{EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);EmployeeMapper mapper1 = sqlSession1.getMapper(EmployeeMapper.class);Employee emp01 = mapper.getEmpById(1);System.out.println(emp01);sqlSession.close();Employee emp02 = mapper1.getEmpById(1);System.out.println(emp02);sqlSession1.close();}finally {sqlSession.close();}}

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二级缓存失效

只有会话提交或者关闭以后，一级缓存中的数据才会转移到二级缓存中

  @Testpublic void testSecondLevelCache() throws IOException {SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();SqlSession sqlSession = sqlSessionFactory.openSession();SqlSession sqlSession1 =   sqlSessionFactory.openSession();try{EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);EmployeeMapper mapper1 = sqlSession1.getMapper(EmployeeMapper.class);Employee emp01 = mapper.getEmpById(1);System.out.println(emp01);Employee emp02 = mapper1.getEmpById(1);System.out.println(emp02);sqlSession.close();sqlSession1.close();}finally {}}