I noticed the following behavior that feels like a bug to me, but I want to
confirm if it's not by design before opening an issue in github.
jackson-databind-2.4.3
Consider the following code fragment:
ByteBuf in = ... // a bytebuf containing multiple jsons,
e.g. {"ack":"a1"}{"ack":"b1"}{"ack":"b3"}
ByteBufInputStream inputStream = new ByteBufInputStream(in);
Map<String, String> ackMap = mapper.readValue(inputStream, Map.class);
After this readValue() call, inputStream becomes empty (nothing left to
read) but only the first {"ack":"a1"} object is parsed and returned. I
debugged it a bit, here's what's happening:
ObjectMapper.readValue(InputStream src, Class<T> valueType) calls _
jsonFactory.createParser(src) which calls
ByteSourceJsonBootstrapper.detectEncoding() which calls
ByteSourceJsonBootstrapper.ensureLoaded(4).
ensureLoaded(4) basically tries to read 4k bytes from the stream.
If the input stream contains multiple small (less than 4k?) json objects,
it reads everything from the stream, *just to detect the encoding!*
The problem with this approach is that once the data is read from the
stream it is essentially lost for the user of object mapper, so if we have
a stream that contains a series of small json strings, it'll read all of it
just to detect the encoding but will only return the first json from
readValue() call.
Since ObjectMapper doesn't "own" the stream, one may expect that it won't
consume more data from the stream than is necessary to parse *one *json
object.
I've also tried this with the latest 2.9.8 release and the behavior is the
same.
Is this a bug?
--
You received this message because you are subscribed to the Google Groups
"jackson-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
For more options, visit https://groups.google.com/d/optout.
