Hi Andrea,
We've done something similar in GeoMesa. We needed to implement a
JsonPathPropertyAccessor[1] and a JsonPathFilterFunction[2]. We used
Jayway for that and maybe json-simple2 somewhere along the way.
The unit tests cover lots of little corner cases we've already fussed
through.
Does any of this look useful?
Cheers,
Jim
1.
https://github.com/locationtech/geomesa/blob/master/geomesa-features/geomesa-feature-kryo/src/main/scala/org/locationtech/geomesa/features/kryo/json/JsonPathPropertyAccessor.scala
https://github.com/locationtech/geomesa/blob/master/geomesa-features/geomesa-feature-kryo/src/test/scala/org/locationtech/geomesa/features/kryo/json/JsonPathPropertyAccessorTest.scala
2.
https://github.com/locationtech/geomesa/blob/master/geomesa-features/geomesa-feature-kryo/src/main/scala/org/locationtech/geomesa/features/kryo/json/JsonPathFilterFunction.scala
https://github.com/locationtech/geomesa/blob/master/geomesa-features/geomesa-feature-kryo/src/test/scala/org/locationtech/geomesa/features/kryo/json/JsonPathFilterFunctionTest.scala
On 1/23/19 4:29 PM, Torben Barsballe wrote:
For completeness, we actually have a few more JSON libraries in
GeoTools/GeoServer in addition to what you listed:
* Google GSON for MongoDB and ArcGIS REST (in GeoTools) and for WMS
TopoJSON format and the GeoGig community module (in GeoServer),
which is active.
* Jettison 1.0.1 (via XStream) for the JSON portion of the REST API
(Only in GeoServer). While the project is active, we're stuck on a
10-year old version for backwards compatibility reasons.
GSON is primarily intended for transforming Java to and from JSON ,
but it does have minimal JsonPath
<https://google.github.io/gson/apidocs/com/google/gson/stream/JsonReader.html#getPath-->
support (With more robust integration added by the Jayway
implementation that you already mentioned). There's also a seemingly
abandoned fork
<https://github.com/johnnylambada/gson/commit/344bd2fd4911146e761926d5ee1b441ba6bb9cfa>
that adds Json-Pointer support.
Overall, it seems like GSON doesn't quite have the capabilities you
are looking for, but it is already a dependency of some GeoTools
modules so maybe consider it?
More generally, I'd definitely say go for a JSON library we already
depend upon (given that we have too many already), be it Jackson or
something else.
I think it's reasonable to add Jackson to gt-main. Having a JSON
library as part of a core module might encourage others to use it
rather than adding their own (although I rather doubt it).
Torben
On Wed, Jan 23, 2019 at 8:24 AM Ian Turton <ijtur...@gmail.com
<mailto:ijtur...@gmail.com>> wrote:
I'd say go for Jackson as a main dependency and then someone (or
me) could try to bring the other JSON modules uptodate by using
it, I might even merge the two at the same time, but not until the
weekend :-)
Ian
On Wed, 23 Jan 2019 at 15:45, Andrea Aime
<andrea.a...@geo-solutions.it
<mailto:andrea.a...@geo-solutions.it>> wrote:
Hi all,
as you probably know GeoTools is now sometimes carrying around
JSON in feature attributes
(e.g., see JSON support in PostGIS data store).
The JSON is represented as a String.
Now, I'd like to add a filter function to parse and extract
specific properties out of the JSON string... which
requires new dependencies. And boy we have a mess of them in
the classpath already:
* json-simple, used in geojson and mbstyles, but dead, last
release is 2012
* json-lib, used in GeoServer for geojson generation, and
also dead, last release is 2010
* jackson, used by Spring and directly by some GeoServer
community modules, with recent releases and latest commits
of only a few days ago
There are basically two languages to extract stuff from JSON,
json-path and json-pointer.
json-path is the one I would have preferred as it's more
powerful, but its situation library wise is not
exactly in great shape, the jayway implementation uses yet
another json java library, json-smart2, also dead.
There are a couple of other options for json-path, either dead
or with a bizzarre "do not evil" licence.
json-pointer is instead supported directly by jackson-core,
which is well alive, and comes with a 300kb jar
that has no external dependencies. This seems the best bet,
just one hesitation... should I add a jackson-core
to gt-main? On one side, it seems a large-ish dependency for
just a function, on the other side having a single
class new module also seems a bit overkill.
Opinions?
Cheers
Andrea
== GeoServer Professional Services from the experts! Visit
http://goo.gl/it488V for more information. == Ing. Andrea Aime
@geowolf Technical Lead GeoSolutions S.A.S. Via di Montramito
3/A 55054 Massarosa (LU) phone: +39 0584 962313 fax: +39 0584
1660272 mob: +39 339 8844549 http://www.geo-solutions.it
http://twitter.com/geosolutions_it
------------------------------------------------------- /Con
riferimento alla normativa sul trattamento dei dati personali
(Reg. UE 2016/679 - Regolamento generale sulla protezione dei
dati “GDPR”), si precisa che ogni circostanza inerente alla
presente email (il suo contenuto, gli eventuali allegati,
etc.) è un dato la cui conoscenza è riservata al/i solo/i
destinatario/i indicati dallo scrivente. Se il messaggio Le è
giunto per errore, è tenuta/o a cancellarlo, ogni altra
operazione è illecita. Le sarei comunque grato se potesse
darmene notizia. This email is intended only for the person or
entity to which it is addressed and may contain information
that is privileged, confidential or otherwise protected from
disclosure. We remind that - as provided by European
Regulation 2016/679 “GDPR” - copying, dissemination or use of
this e-mail or the information herein by anyone other than the
intended recipient is prohibited. If you have received this
email by mistake, please notify us immediately by telephone or
e-mail./
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
<mailto:GeoTools-Devel@lists.sourceforge.net>
https://lists.sourceforge.net/lists/listinfo/geotools-devel
--
Ian Turton
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
<mailto:GeoTools-Devel@lists.sourceforge.net>
https://lists.sourceforge.net/lists/listinfo/geotools-devel
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geotools-devel
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geotools-devel
