[BUG] Generic Client with Custom Deserializer fails to deserialize aggregations

[dsinghal-nice]

What is the bug? I am using opensearch-java client 2.12.0

Describe the issue: I have a specific requirement where I will be using aggregations on a index, but I want to use SQL plugin for that. Since the response for the aggregations from OpenSearchClient is very complicated.

I am trying to deserialize the response but getting below error:

Exception in thread "main" jakarta.json.stream.JsonParsingException: Property name 'year' is not in the 'type#name' format. Make sure the request has 'typed_keys' set.

final String body = response.getBody().map(org.opensearch.client.opensearch.generic.Body::bodyAsString).orElse("");

I get the below response as part of Response body

{"took":17,"timed_out":false,"_shards":{"total":5,"successful":5,"skipped":0,"failed":0},"hits":{"total":{"value":1,"relation":"eq"},"max_score":null,"hits":[]},"aggregations":{"year":{"doc_count_error_upper_bound":0,"sum_other_doc_count":0,"buckets":[{"key":1960,"doc_count":1,"COUNT(1)":{"value":0}}]}}}

Below is the code I am trying to deserialize the response

JacksonJsonpMapper jacksonJsonpMapper = new JacksonJsonpMapper();
            final SearchResponse<Book> result = response.getBody().
                    map(b -> Bodies.json(b, SearchResponse.createSearchResponseDeserializer(Book.createBookDeserializer()), jacksonJsonpMapper))
                    .orElse(null);

Below is my code for the same

private static void searchUsingGenericClient(OpenSearchGenericClient openSearchGenericClient) throws IOException {
    JsonObject jsonObject = Json.createObjectBuilder().add("query", "SELECT title, count(1) from books_test where year > 1951 group by year").build();

    try (org.opensearch.client.opensearch.generic.Response response = openSearchGenericClient
            .execute(
                    Requests.builder()
                            .endpoint("/_plugins/_sql?format=json")
                            .method("POST")
                            .json(jsonObject)
                            .build())) {
        // Retrieve the response body as a simple string
        final String body = response.getBody().map(org.opensearch.client.opensearch.generic.Body::bodyAsString).orElse("");

        JacksonJsonpMapper jacksonJsonpMapper = new JacksonJsonpMapper();
        final SearchResponse<Book> result = response.getBody().
                map(b -> Bodies.json(b, SearchResponse.createSearchResponseDeserializer(Book.createBookDeserializer()), jacksonJsonpMapper))
                .orElse(null);

        System.out.println("object conversion from generic client :: " + result.hits().hits().get(0).source());
    }
    System.out.println("End searchUsingGenericClient :: ");
}

Do you have any additional context? (https://forum.opensearch.org/t/generic-client-with-custom-deserializer-fails-to-deserialize-aggregations/20739)

[dblock]

[Weekly Catch All Triage - 1]