在JPA存储库中使用@MOdify和@Query有哪些规则支配? [英] What rules govern using @MOdify and @Query in JPA Repository?

问题描述

现在我的项目已成功完成，我们正在尝试记录所汲取的经验教训.仍然让我感到困惑的是以下内容:

Now that my project is successfully completed, we are trying to document lessons learned. One that still confuses me is the following:

我们有一个地址数据库，并且在用户开始输入街道名称时需要自动完成.使用JPA存储库，我们实现了一个PString类(简单地是一个String的持久包装器)，然后实现了以下接口:

We have a database of addresses, and needed to autocomplete when a User started typing in a street name. Using JPA repository, we implemented a PString class (simply a persistent wrapper for a String), and then implemented this interface:

@RepositoryRestResource(collectionResourceRel = "locations", path = "locations")
public interface LocationRepository extends JpaRepository<Location, Integer>, LocationRepositoryCustom {
   List<Location> findByStreetNameAndCommunity_ID(@Param("street") String streetName, @Param("commId") Integer commId);

   @Modifying
   @Query("select distinct x.streetName from Location x where x.streetName like :street%")
   List<PString> findStreetNameStartingWith(@Param("street") String streetName);
}

尝试通过网络致电location/search/findStreetNameStartingWith?street = N％20College导致:

Trying to call locations/search/findStreetNameStartingWith?street=N%20College over the web resulted in:

{"cause":null，"message":"PersistentEntity不能为null！"}

{"cause":null,"message":"PersistentEntity must not be null!"}

但是，我们添加了一个控制器来调用该方法:

However, we added a controller to call the method:

@RestController
@RequestMapping("/custom/locations")
public class LocationController {

   @Autowired
   private LocationRepository repo;

   @RequestMapping(value = "/findStreetNamesStartingWith", method=RequestMethod.GET)
   public List<PString> findStreetNameStartingWith(
        @Param("streetName") String streetName) {

      return repo.findStreetNameStartingWith(streetName);
   }
}

调用/custom/locations/findStreetNamesStartingWith?streetName = N％20Coll返回预期的三个结果.为什么直接调用该方法不起作用，但是通过控制器通过管道运行时却像灵缇一样运行?

Calling /custom/locations/findStreetNamesStartingWith?streetName=N%20Coll returns the expected three results. Why does the method not work if called directly, but runs like a greyhound when we pipe it through a controller?

推荐答案

确保已配置

Make sure you configured Spring Data REST properly, like adding the RepositoryRestConfiguration:

@Configuration
public class CustomizedRestMvcConfiguration extends RepositoryRestMvcConfiguration {

  @Override
  public RepositoryRestConfiguration config() {
    RepositoryRestConfiguration config = super.config();
    config.setBasePath("/custom");
    return config;
  }
}

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