Possible bug building SortOptions object from json

[aianta]

Java API client version

8.7.1

Java version

19.0.1

Elasticsearch Version

8.4.3

Problem description

I'm trying to create a SortOptions object for an elastic search query using the Create API objects from JSON data method. But I keep getting the following exception:

class co.elastic.clients.json.JsonpDeserializer$3 cannot be cast to class co.elastic.clients.json.ObjectDeserializer (co.elastic.clients.json.JsonpDeserializer$3 and co.elastic.clients.json.ObjectDeserializer are in unnamed module of loader 'app')
java.lang.ClassCastException: class co.elastic.clients.json.JsonpDeserializer$3 cannot be cast to class co.elastic.clients.json.ObjectDeserializer (co.elastic.clients.json.JsonpDeserializer$3 and co.elastic.clients.json.ObjectDeserializer are in unnamed module of loader 'app')
    at co.elastic.clients.util.WithJsonObjectBuilderBase.withJson(WithJsonObjectBuilderBase.java:53)
    at co.elastic.clients.json.WithJson.withJson(WithJson.java:57)
    at ElasticsearchFromJsonTest.lambda$parseSortOptions$0(ElasticsearchFromJsonTest.java:27)
    at co.elastic.clients.elasticsearch._types.SortOptions.of(SortOptions.java:119)
    at ElasticsearchFromJsonTest.parseSortOptions(ElasticsearchFromJsonTest.java:27)
...

Code sample:

import co.elastic.clients.elasticsearch._types.SortOptions;

import org.junit.jupiter.api.Test;
import java.io.StringReader;

public class ElasticsearchFromJsonTest {

    @Test
    void parseSortOptions(){

        String test = """
                {
                  "sort" : [
                    { "term" : "asc"}
                  ]
                }
                """;

        SortOptions so = SortOptions.of(b->b.withJson(new StringReader(test)));

    }

}

I've also tried setting test to:

[{"term" : "asc"}]

And got the same results. I'll admit the 'bug' may just be in my simple minded interpretation of what subsection/format of json input is required to get this to work 😓, on the plus side that would be an easy fix.

[l-trotta]

Hello, thank you for the report! Definitely a bug, we'll investigate this.

[prchen]

For new guests to this issue, this comment may help you resolve this ancient issue temporarily 😂

I've figured out a possible solution by copying and override some source code:

1. Write a child class for SortOptions.Builder
2. Override withJson methods to make it works
3. Build SortOptions instance one-by-one for each item in the sort array

Code example:

import co.elastic.clients.elasticsearch._types.SortOptions;
import co.elastic.clients.json.JsonpMapper;
import com.fasterxml.jackson.databind.ObjectMapper;
import jakarta.json.stream.JsonParser;

import java.io.StringReader;
import java.util.Map;

public class DummySortOptionBuilder extends SortOptions.Builder {

    @Override
    public SortOptions.Builder withJson(JsonParser parser, JsonpMapper mapper) {
        var option = SortOptions._DESERIALIZER.deserialize(parser, mapper);
        if (option.isScore()) {
            score(option.score());
        } else if (option.isDoc()) {
            doc(option.doc());
        } else if (option.isGeoDistance()) {
            geoDistance(option.geoDistance());
        } else if (option.isScript()) {
            script(option.script());
        } else if (option.isField()) {
            field(option.field());
        }
        return this;
    }

    public static SortOptions fromJson(String json) {
        return new DummySortOptionBuilder()
                .withJson(new StringReader(json))
                .build();
    }

    public static void main(String[] args) throws Exception {
        var mapper = new ObjectMapper();

        // sort by score
        System.out.println(fromJson(mapper.writeValueAsString("_score")));
        System.out.println(fromJson("\"_score\""));

        // sort by doc
        System.out.println(fromJson(mapper.writeValueAsString("_doc")));
        System.out.println(fromJson("\"_doc\""));

        // sort by field
        System.out.println(fromJson(mapper.writeValueAsString("term")));
        System.out.println(fromJson("\"term\""));

        // sort by field with options
        System.out.println(fromJson(mapper.writeValueAsString(Map.of("term", "asc"))));
        System.out.println(fromJson("{\"term\" : \"asc\"}"));
    }
}

[li-a]

More directly, the workaround would be to avoid these two forms:

"sort" : [
    "_score"
]

"sort" : [
    { "myField": "asc" }
]

and instead, construct the JSON with the most verbose form:

"sort" : [
    { "_score": { "order": "desc" } }
]

"sort" : [
    { "myField": { "order": "asc" } }
]