Saving json array into postgresql data using spring boot java API

Question

I have a Json Array in my request object and POJO object, I need to save that jsonarray field into jsonb column in my postgresql table.

"productId": "1",
"product":[ 
     {
     "name": "PENCIL",
     "quantity":"5"
     }]

I am getting an exception when trying to hit it via postman, getting exception:

Type definition error: [simple type, class io.r2dbc.postgresql.codec.Json]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of io.r2dbc.postgresql.codec.Json (no Creators, like default constructor, exist): abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information\n at [Source: (io.netty.buffer.ByteBufInputStream); l

Answer 1

Create a converter for reading and a converter for writing, thus it will convert between your type and Postgres io.r2dbc.postgresql.codec.Json.

@ReadingConverter
@RequiredArgsConstructor
public class JsonToYourTypeConverter implements Converter<Json, YourType > {
    private final ObjectMapper objectMapper;
    @Override
    public YourType convert(Json json) {
    }
}

@WritingConverter
@RequiredArgsConstructor
public class YourTypeToJsonConverter implements Converter<YourType, Json > {
    private final ObjectMapper objectMapper;
    @Override
    public Json convert(YourType data) {
    }
}

Then register your converters via R2dbcCustomConversions bean.

@Bean
public R2dbcCustomConversions r2dbcCustomConversions(ConnectionFactory connectionFactory, ObjectMapper objectMapper) {
    var dialect = DialectResolver.getDialect(connectionFactory);
    var converters = List.of(
            new JsonToYourTypeConverter(objectMapper),
            new YourTypeToJsonConverter(objectMapper),
    );
    return R2dbcCustomConversions.of(dialect, converters);
}