Hibernate 5 二级缓存不工作，仍在从数据库中获取

Question

我计划用 Hibernate 5 实现二级缓存。实体 class 用 @Cacheable 注释并添加策略 CacheConcurrencyStrategy.READ_WRITE 。但它仍在数据库中而不是缓存中寻找数据。日志显示 2 SQL 个查询。

请看我的主要方法

public static void main(String[] args) {
    HolidayDAOImpl holidayImpl = new HolidayDAOImpl();
    holidayImpl.setSessionFactory(HibernateUtil.INSTANCE.getSessionFactoryInstance());
    holidayImpl.load().forEach(System.out :: println);
    System.out.println("Loading second time");
    holidayImpl.load().forEach(System.out::println);
}

请参阅 HibernateUtil 枚举

public enum HibernateUtil{
INSTANCE;

public SessionFactory getSessionFactoryInstance(){  
    Properties properties = new Properties();
    properties.setProperty(Environment.URL, "jdbc:mysql://dummy");
    properties.setProperty(Environment.DIALECT, "org.hibernate.dialect.MySQLDialect");
    properties.setProperty(Environment.DRIVER, "com.mysql.jdbc.Driver");
    properties.setProperty(Environment.USER, "demo");
    properties.setProperty(Environment.PASS, "demo");

    //second level cache prop

    properties.setProperty(Environment.USE_SECOND_LEVEL_CACHE, "true");
    properties.setProperty(Environment.USE_QUERY_CACHE, "true");
    properties.setProperty(Environment.CACHE_REGION_FACTORY, "org.hibernate.cache.ehcache.EhCacheRegionFactory");

    //logging

    properties.setProperty("hibernate.show_sql","true");
    properties.setProperty("hibernate.format_sql","true");

    Configuration cfg = new Configuration();
    cfg.setProperties(properties);
    cfg.addAnnotatedClass(Holidays.class);
    StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(cfg.getProperties()).build();
    SessionFactory sessionFactory = cfg.buildSessionFactory(serviceRegistry);
    return sessionFactory;
}
}

请参阅 DAOImpl class

public List<Holidays> load() {
    try (Session session = sessionFactory.openSession()) {

        //List<Holidays> result = session.createQuery("from Holidays", Holidays.class).getResultList();
        Criteria criteria  = session.createCriteria(Holidays.class);
        criteria.add(Restrictions.like("holiday_name", "%QA%"));

        return criteria.list();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

pom.xml

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.13</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.4.1.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-ehcache</artifactId>
        <version>5.4.1.Final</version>
    </dependency>
</dependencies>

在查看一些堆栈溢出的答案时，可以了解到在最新版本的 Hibernate（版本 4 之后）中，配置发生了一些变化。不确定我在配置中是否有任何错误。

谁能调查一下，弄清楚为什么它仍在寻找数据库而不是缓存？

Answer 1

要使用 hibernate 查询缓存，您必须在每个查询中添加 setCacheable (true)。

如果在DAOImplclass中添加criteria.setCacheable (true);，则第二个查询结果来自缓存。

Hibernate 5 二级缓存不工作，仍在从数据库中获取

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