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 的方式。

感觉有点笨拙。我很想听到一个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

Extend RootResourceInformationHandlerMethodArgumentResolver

这些是代码片段，它们基于 http 查询参数创建我自己的 Map 搜索谓词。再次 - 很想知道更好的方法。

该方法调用：postProcess

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

就在引用传递到构造函数并返回之前。predicateQuerydslRepositoryInvokerAdapter

这是该方法：addCustomMapPredicates

    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(".*[^.]\\[.*[^\\[]");

我花了几天时间研究如何做到这一点。最后，我只是手动添加到谓词中。这个解决方案感觉简单而优雅。

因此，您可以通过以下方式访问地图

GET /api/meetup?properties.aKey=aValue

在控制器上，我注入了请求参数和谓词。

public List<Meetup> getMeetupList(@QuerydslPredicate(root = Meetup.class) Predicate predicate,
                                                @RequestParam Map<String, String> allRequestParams,
                                                Pageable page) {
    Predicate builder = createPredicateQuery(predicate, allRequestParams);
    return meetupRepo.findAll(builder, page);
}

然后，我只是简单地解析查询参数并添加包含

private static final String PREFIX = "properties.";

private BooleanBuilder createPredicateQuery(Predicate predicate, Map<String, String> allRequestParams) {
    BooleanBuilder builder = new BooleanBuilder();
    builder.and(predicate);
    allRequestParams.entrySet().stream()
            .filter(e -> e.getKey().startsWith(PREFIX))
            .forEach(e -> {
                var key = e.getKey().substring(PREFIX.length());
                builder.and(QMeetup.meetup.properties.contains(key, e.getValue()));
            });
    return builder;
}