Ways to build Json doc in ES8 Java API client

[ijaxahmed (Ijaz Ahmed)]

How to build Json document In Elasticsearch 8 API client , as In older Client APIs its possible to build using XContentBuilder like

XContentBuilder builder = jsonBuilder()
    .startObject()
        .field("firstName", "jhon")
        .field("lastname", "doe")
        .field("message", "trying out Elasticsearch")
    .endObject()```

But now in ES8 Java API Client i do not see any way to build Json doc, for example if i want to insert a "Student" into "School" index , then possible ways are

1- using direct bean as document

esClient.index(i -> i
    .index("school")
    .id(product.getId())
    .document(student)

2- using pre builded json as string (no way to build explicitly)

Reader input = new StringReader(
    "{'@timestamp': '2022-04-08T13:55:32Z', 'firstName': 'jhone', 'lastName': 'doe'}"
    .replace('\'', '"'));

IndexRequest<JsonData> request = IndexRequest.of(i -> i
    .index("school")
    .withJson(input)
);

3- using JsonData class

JsonpMapper jsonpMapper = esClient.jsonpMapper();
JsonData jsonData = JsonData.of(student , jsonpMapper);

esClient.index(i -> i
    .index("school")
    .id(product.getId())
    .document(jsonData)

so is there any way to build Json using Java API Client and input as doc to index

[swallez (Sylvain Wallez)]

Indeed, there is no way to programmatically build JSON in the Java API client, and this is a deliberate omission.

JsonData can hold any object that can be serialized to JSON: this can be a map, a domain object that will be serialized to JSON, etc.

The withJson method is meant to load JSON from text-based sources, like copy/pasting from the Kibana dev console. For example:

        var object = Map.ofEntries(
            Map.entry("firstName", "John"),
            Map.entry("lastName", "Doe"),
            Map.entry("message", "trying out Elasticsearch")
        );

        esClient.index(i -> i
            .index("school")
            .id(product.getId())
            .document(JsonData.of(object))
        );

Hope this helps.