Is it possible to make json4s not to throw exception when required field is missing?

Question

Is it possible to make json4s not to throw exception when required field is missing ?

When I \"extract\" object from raw json string it throws exception like this on

Answer 1

I've dealt with this problem when dealing with data migrations, and I wanted default values to fill undefined fields.

My solution was to merge the defaults into the JValue before extracting the result.

  val defaultsJson = Extraction.decompose(defaults)
  val valueJson = JsonUtil.jValue(v)
  (defaultsJson merge valueJson).extract[T]

JsonUtil.scala

  import org.json4s._

  object JsonUtil {
    import java.nio.charset.StandardCharsets.UTF_8
    import java.io.{InputStreamReader, ByteArrayInputStream}

    def jValue(json: String): JValue = {
      jValue(json.getBytes(UTF_8))
    }

    def jValue(json: Array[Byte]): JValue = {
      val reader = new InputStreamReader(new ByteArrayInputStream(json), UTF_8)
      native.JsonParser.parse(reader)
    }
  }