Class JsonFraming

  • public class JsonFraming
    extends java.lang.Object
    Provides JSON framing operators that can separate valid JSON objects from incoming ByteString objects.
    • Constructor Detail

      • JsonFraming

        public JsonFraming()
    • Method Detail

      • objectScanner

        public static Flow<ByteString,​ByteString,​NotUsed> objectScanner​(int maximumObjectLength)
        Returns a Flow that implements a "brace counting" based framing operator for emitting valid JSON chunks. It scans the incoming data stream for valid JSON objects and returns chunks of ByteStrings containing only those valid chunks.

        Typical examples of data that one may want to frame using this operator include:

        **Very large arrays**:

           [{"id": 1}, {"id": 2}, [...], {"id": 999}]

        **Multiple concatenated JSON objects** (with, or without commas between them):

           {"id": 1}, {"id": 2}, [...], {"id": 999}

        The framing works independently of formatting, i.e. it will still emit valid JSON elements even if two elements are separated by multiple newlines or other whitespace characters. And of course is insensitive (and does not impact the emitting frame) to the JSON object's internal formatting.

        If the stream completes while mid-object, the stage will fail with a JsonFraming.PartialObjectException.

        maximumObjectLength - The maximum length of allowed frames while decoding. If the maximum length is exceeded this Flow will fail the stream.