我想使用Spring Data Elasticsearch从ES获取聚合，代码如下（在服务中）：

public SearchHits<Document> getDocumentMetadata() {
    Query query = new NativeSearchQueryBuilder()
        .withAggregations(terms("documents-aggr").field("type.keyword"))
        .withQuery(QueryBuilders.matchAllQuery())
        .withMaxResults(0)
        .build();

    return elasticsearchOperations.search(query, Document.class);
}

在控制器中，代码看起来像这样：

@GetMapping("documents")
public SearchHits<Document> getDocumentsMetadata() {
    return documentService.getDocumentMetadata();
}

Document类非常简单，看起来像这样：

@Data
@NoArgsConstructor
@AllArgsConstructor
@org.springframework.data.elasticsearch.annotations.Document(indexName = "rtk-documents")
public class Document {

  private List<String> authors;
  private String title;
  private DocumentType type;
}

当我向这个端点发送请求时，我得到：

{
    "timestamp": "2022-04-26T10:52:28.653+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "path": "/documents"
}

内部异常看起来像这样：

2022-04-26 12:52:28.648 ERROR 277610 --- [io-10210-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class org.springframework.data.elasticsearch.core.clients.elasticsearch7.ElasticsearchAggregations]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.springframework.data.elasticsearch.core.clients.elasticsearch7.ElasticsearchAggregations and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: org.springframework.data.elasticsearch.core.SearchHitsImpl["aggregations"])] with root cause

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.springframework.data.elasticsearch.core.clients.elasticsearch7.ElasticsearchAggregations and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: org.springframework.data.elasticsearch.core.SearchHitsImpl["aggregations"])
    at 
    ...

使用的版本：

• spring-boot-starter-web，spring-data-elasticsearch：2.6.7

我想知道如何使控制器序列化ES的答案并将其发送到客户端。我搜索了这个问题，但没有找到任何与我的问题相关的答案。