Re: [hibernate-dev] [HSEARCH] Geospatial indexing and queries
Hi Emmanuel,
I'm not familiar of what kind of API a gis expert would expect so I'm
commenting only as a JPA user who might need to introduce some "close
to" feature.
Assuming we can get the API to support overloading without enforcing
the JTS library as a hard dependency, could we do something like:
SomeType centeredOn(JTSLocation jts); // for the more experts
SomeType centeredOn(long latitude, long longitude); // the simple one
[cut]
To answer your question on "centeredOn", I'd avoid a strong dependency
on JTS. The "Object" option you propose could be an interface, and we
create a factory class which returns them; users should then be able
to use the JTS enabled factory or a dumb one.
How would that look in practice?
Maybe it can't work, I was thinking loud about some in this style:
SomeType centeredOn(LocationInterface obj);
And have an helper class which provides different builder-like constructs:
LocationInterface createLocation(JTSLocation jts);
LocationInterface createLocation(long latitude, long longitude);
LocationInterface createLocation(...);
The idea is that you could have two of these helper classes, one
bundled in the search-gis module having the more expressive JTS
methods as well, and a simpler one included in the search-engine.
Also this would make sure the Query fluent API doesn't get too complex
while adding additional (and possibly custom) implementations for
LocationInterface; as a user I'd likely want to create my own
implementation.
(I wouldn't call it "LocationInterface", just to stress I'm thinking
of an interface)
On 19 December 2011 13:15, Emmanuel Bernard <emmanuel(a)hibernate.org> wrote:
On 5 déc. 2011, at 17:01, Sanne Grinovero wrote:
> To answer your question on "centeredOn", I'd avoid a strong dependency
> on JTS. The "Object" option you propose could be an interface, and we
> create a factory class which returns them; users should then be able
> to use the JTS enabled factory or a dumb one.
I've been thinking about your approach but I don't find it too appealing
## Solution 1
SomeType centeredOn(Object jts);
.centeredOn( location.getPoint() );
## Solution 2
SomeType centeredOn(LocationFactory factory);
.centeredOn( new JTSLocation( location.getPoint() ) );
To me solution 2 adds verbosity and is not a lot more typesafe. Granted, the user will
have to find an impl of LocationFactory that matches its need, so the type system guides
him a bit more than raw Object.
Is the extra verbosity worth the extra help here?
Emmanuel
I'm not really understanding solution #2 ..how is this LocationFactory
affecting the query?
#1 seems ok.
Another question; quoting first email again:
"Using a specific interface implemented by the entity:
`o.h.s.spatial.Coordinates`"
but then your Address of the example doesn't implement Coordinates;
did you forget the "implements", or do you intend to just look for the
method signatures of
public double getLatitude()
?
Sanne