json.md

• Working With JSON
  • Serialization
    • Using toJsonString
    • Manual Serialization

Working With JSON

OpenSearch Java client seamlessly integrates with JSON, providing serialization and deserialization capability.

Serialization

For demonstration let's consider an instance of SearchRequest.

SearchRequest searchRequest = SearchRequest.of(
        request -> request.index("index1", "index2")
                .aggregations(Collections.emptyMap())
                .terminateAfter(5L)
                .query(q -> q.match(t -> t.field("name").query(FieldValue.of("OpenSearch"))))
);

Using toJsonString

For classes implementing PlainJsonSerializable, which extends JsonpSerializable, a default toJsonString method is provided. This implementation uses jakarta.json.spi.JsonProvider SPI to discover the available JSON provider instance from the classpath and to create a new mapper. The JsonpUtils utility class streamlines this serialization process. The following code example demonstrates how to use the toJsonString method to serialize objects:

String requestString = searchRequest.toJsonString();

Manual Serialization

For classes implementing the JsonpSerializable interface, a serialize method is provided, which takes a mapper and a generator as arguments and returns the JSON string representation of the instance.

The following sample code demonstrates how to serialize an instance of a Java class:

private String toJson(JsonpSerializable object) {
  try (StringWriter writer = new StringWriter()) {
    JsonbJsonpMapper mapper = new JsonbJsonpMapper();
    try (JsonGenerator generator = mapper.jsonProvider().createGenerator(writer)) {
      serialize(generator, mapper);
    }
    return writer.toString();
  } catch (IOException ex) {
    throw new UncheckedIOException(ex);
  }
}