QueryDsl Web查询Map字段的键

Question

概观

特定

• Spring Data JPA,Spring Data Rest,QueryDsl
• 一个Meetup实体
  • 与一个Map<String,String> properties领域
    • MEETUP_PROPERTY作为一个坚持在一张桌子@ElementCollection
• 一个 MeetupRepository
  • 延伸 QueryDslPredicateExecutor<Meetup>

我期待

一个Web查询

GET /api/meetup?properties[aKey]=aValue

仅返回具有指定键和值的属性条目的Meetup:aKey = aValue.

但是,这对我不起作用.我错过了什么？

试着

简单的领域

简单字段起作用,如名称和描述:

GET /api/meetup?name=whatever

与参与者一样,收集字段起作用

GET /api/meetup?participants.name=whatever

但不是这个Map字段.

自定义QueryDsl绑定

我已经尝试通过拥有存储库来自定义绑定

extend QuerydslBinderCustomizer<QMeetup>

并凌驾于

customize(QuerydslBindings bindings, QMeetup meetup)

方法,但是当customize()方法被命中时,lambda内的绑定代码不是.

编辑:了解这是因为QuerydslBindings评估查询参数的方法不会让它与pathSpecs它内部持有的地图相匹配- 它有自定义绑定.

一些细节

Meetup.properties字段

@ElementCollection(fetch = FetchType.EAGER)
@CollectionTable(name = "MEETUP_PROPERTY", joinColumns = @JoinColumn(name = "MEETUP_ID"))
@MapKeyColumn(name = "KEY")
@Column(name = "VALUE", length = 2048)
private Map<String, String> properties = new HashMap<>();

定制的querydsl绑定

编辑:见上文; 事实证明,这对我的代码没有任何作用.

public interface MeetupRepository extends PagingAndSortingRepository<Meetup, Long>,
                                          QueryDslPredicateExecutor<Meetup>,
                                          QuerydslBinderCustomizer<QMeetup> {

    @Override
    default void customize(QuerydslBindings bindings, QMeetup meetup) {
        bindings.bind(meetup.properties).first((path, value) -> {
            BooleanBuilder builder = new BooleanBuilder();
            for (String key : value.keySet()) {
                builder.and(path.containsKey(key).and(path.get(key).eq(value.get(key))));
            }
            return builder;
        });
}

其他调查结果

1. QuerydslPredicateBuilder.getPredicate()要求QuerydslBindings.getPropertyPath()尝试两种方法来返回一个路径,以便它可以创建一个QuerydslAwareRootResourceInformationHandlerMethodArgumentResolver.postProcess()可以使用的谓词.
   • 1是查看自定义绑定.我没有看到任何方式在那里表达地图查询
   • 2是默认为Spring的bean路径.那里的表达问题相同.你怎么表达地图？因此,看起来无法QuerydslPredicateBuilder.getPredicate()自动创建谓词.很好 - 我可以手动完成,如果我可以挂钩QuerydslAwareRootResourceInformationHandlerMethodArgumentResolver.postProcess()

我该如何覆盖该类,或者替换bean？它被实例化并作为RepositoryRestMvcConfiguration.repoRequestArgumentResolver()bean声明中的bean 返回.

2. 我可以通过声明我自己的repoRequestArgumentResolverbean 来覆盖该bean ,但它不会被使用.
   • 它会被RepositoryRestMvcConfigurations 覆盖.我不能强制设置它,它@Primary还是@Ordered(HIGHEST_PRECEDENCE).
   • 我可以通过显式组件扫描强制它RepositoryRestMvcConfiguration.class,但这也会混淆Spring Boot的自动配置,因为它会导致 RepositoryRestMvcConfiguration's在任何自动配置运行之前处理bean声明.除此之外,这导致杰克逊以不必要的方式序列化的回应.

问题

嗯 - 看起来像我预期的支持不存在.

所以问题就变成了: 我如何正确地覆盖repoRequestArgumentResolverbean？

顺便说一句 - QuerydslAwareRootResourceInformationHandlerMethodArgumentResolver尴尬地非公开.:/

Answer 1

更换豆子

实施应用程序上下文感知

这就是我在应用程序上下文中替换 bean 的方法。

感觉有点老套。我很想听到更好的方法来做到这一点。

@Configuration
public class CustomQuerydslHandlerMethodArgumentResolverConfig implements ApplicationContextAware {

    /**
     * This class is originally the class that instantiated QuerydslAwareRootResourceInformationHandlerMethodArgumentResolver and placed it into the Spring Application Context
     * as a {@link RootResourceInformationHandlerMethodArgumentResolver} by the name of 'repoRequestArgumentResolver'.<br/>
     * By injecting this bean, we can let {@link #meetupApiRepoRequestArgumentResolver} delegate as much as possible to the original code in that bean.
     */
    private final RepositoryRestMvcConfiguration repositoryRestMvcConfiguration;

    @Autowired
    public CustomQuerydslHandlerMethodArgumentResolverConfig(RepositoryRestMvcConfiguration repositoryRestMvcConfiguration) {
        this.repositoryRestMvcConfiguration = repositoryRestMvcConfiguration;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        DefaultListableBeanFactory beanFactory = (DefaultListableBeanFactory) ((GenericApplicationContext) applicationContext).getBeanFactory();
        beanFactory.destroySingleton(REPO_REQUEST_ARGUMENT_RESOLVER_BEAN_NAME);
        beanFactory.registerSingleton(REPO_REQUEST_ARGUMENT_RESOLVER_BEAN_NAME,
                                      meetupApiRepoRequestArgumentResolver(applicationContext, repositoryRestMvcConfiguration));
    }

    /**
     * This code is mostly copied from {@link RepositoryRestMvcConfiguration#repoRequestArgumentResolver()}, except the if clause checking if the QueryDsl library is
     * present has been removed, since we're counting on it anyway.<br/>
     * That means that if that code changes in the future, we're going to need to alter this code... :/
     */
    @Bean
    public RootResourceInformationHandlerMethodArgumentResolver meetupApiRepoRequestArgumentResolver(ApplicationContext applicationContext,
                                                                                                     RepositoryRestMvcConfiguration repositoryRestMvcConfiguration) {
        QuerydslBindingsFactory factory = applicationContext.getBean(QuerydslBindingsFactory.class);
        QuerydslPredicateBuilder predicateBuilder = new QuerydslPredicateBuilder(repositoryRestMvcConfiguration.defaultConversionService(),
                                                                                 factory.getEntityPathResolver());

        return new CustomQuerydslHandlerMethodArgumentResolver(repositoryRestMvcConfiguration.repositories(),
                                                               repositoryRestMvcConfiguration.repositoryInvokerFactory(repositoryRestMvcConfiguration.defaultConversionService()),
                                                               repositoryRestMvcConfiguration.resourceMetadataHandlerMethodArgumentResolver(),
                                                               predicateBuilder, factory);
    }
}

从 http 参数创建地图搜索谓词

扩展 RootResourceInformationHandlerMethodArgumentResolver

这些是基于 http 查询参数创建我自己的地图搜索谓词的代码片段。再次 - 很想知道更好的方法。

该postProcess方法调用：

        predicate = addCustomMapPredicates(parameterMap, predicate, domainType).getValue();

就predicate在引用被传递到构造函数并返回之前QuerydslRepositoryInvokerAdapter。

这是该addCustomMapPredicates方法：

    private BooleanBuilder addCustomMapPredicates(MultiValueMap<String, String> parameters, Predicate predicate, Class<?> domainType) {
        BooleanBuilder booleanBuilder = new BooleanBuilder();
        parameters.keySet()
                  .stream()
                  .filter(s -> s.contains("[") && matches(s) && s.endsWith("]"))
                  .collect(Collectors.toList())
                  .forEach(paramKey -> {
                      String property = paramKey.substring(0, paramKey.indexOf("["));
                      if (ReflectionUtils.findField(domainType, property) == null) {
                          LOGGER.warn("Skipping predicate matching on [%s]. It is not a known field on domainType %s", property, domainType.getName());
                          return;
                      }
                      String key = paramKey.substring(paramKey.indexOf("[") + 1, paramKey.indexOf("]"));
                      parameters.get(paramKey).forEach(value -> {
                          if (!StringUtils.hasLength(value)) {
                              booleanBuilder.or(matchesProperty(key, null));
                          } else {
                              booleanBuilder.or(matchesProperty(key, value));
                          }
                      });
                  });
        return booleanBuilder.and(predicate);
    }

    static boolean matches(String key) {
        return PATTERN.matcher(key).matches();
    }

和模式：

    /**
     * disallow a . or ] from preceding a [
     */
    private static final Pattern PATTERN = Pattern.compile(".*[^.]\\[.*[^\\[]");