akka.stream.javadsl.JsonFraming.scala Maven / Gradle / Ivy
/*
* Copyright (C) 2015-2020 Lightbend Inc.
*/
package akka.stream.javadsl
import akka.NotUsed
import akka.util.ByteString
/** Provides JSON framing operators that can separate valid JSON objects from incoming [[akka.util.ByteString]] objects. */
object JsonFraming {
/**
* Returns a Flow that implements a "brace counting" based framing operator for emitting valid JSON 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.
*
* @param maximumObjectLength The maximum length of allowed frames while decoding. If the maximum length is exceeded
* this Flow will fail the stream.
*/
def objectScanner(maximumObjectLength: Int): Flow[ByteString, ByteString, NotUsed] =
akka.stream.scaladsl.JsonFraming.objectScanner(maximumObjectLength).asJava
}