Question

i am using springboot 1.5.9.RELEASE and i am using spring @Cacheable and what i am trying to accomplish is to cache a country lookup on application startup as follows:

public interface CountryRepository extends JpaRepository<Country, BigInteger> {

    @Cacheable(cacheNames = Constants.CACHE_NAME_ALL_COUNTRIES)
    List<Country> findAll();

}

and call it on startup as follows:

@Component
public class StartUpInit {

    @Autowired
    private CountryRepository countryRepository;

    @EventListener
    public void onApplicationReady(ApplicationReadyEvent ready) {
        List<Country> list = countryRepository.findAll();
    }

}

the obvious thing is that subsequent calls to findAll will load the data from the cache, but what i am trying to do is something like the following :

@Entity
@Table(name = "PROJECT")
public class Project {

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "COUNTRY_ID")
    private Country country;

    @Cacheable(cacheNames = Constants.CACHE_NAME_ALL_COUNTRIES)
    public Country getCountry() {
        return country;
    }

    public void setCountry(Country country) {
        this.country = country;
    }

}

i want when trying to get country from project object the country to be retrieved from the cache instead of database,i know that i can cache the whole project object with all data in it but i don't want to do that i want only to get the lookup inside it from the cache , please advise how to do that.

Answer 1

@Cacheable注释需要放在Spring Beans上，而不是实体上，但我也不认为它适用于存储库。您的配置中还需要@EnableCaching。这是一个很好的教程： Caching Data with Spring显示了一个例子。所以基本上你会创建一个由CountryService支持的CountryRepository，并且在服务上有注释。

修改：无法在实体中使用该注释，@Cacheable必须位于Spring Bean中。您可以做的只是在项目中保存国家/地区的ID，并使用具有缓存的CountryService来检索国家/地区，这将阻止您每次检索Project时访问国家/地区表，但如果你的问题只是如何让@Cacheable在一个不可能的实体中工作。

Cache lookups on application startup and reuse it in hibernate entity

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