Hi,
Sorry if I expressed myself wrong: my data is actually in epsg:4647 and, since
I am using FORCE_LONGITUDE_FIRST_AXIS_ORDER=false, it would be wrong to load
the data in epsg:5652.
Now, since this specific WKT does not contain any information about proper axis
order, from perspective of geotools epsg:5652 is probably a correct answer. I
prefer though Geotools would not deliver just a first matching candidate but a
set of possible matches; for an application or ultimately an user to choose the
correct one from the set. Further I'd prefer CRS.lookupIdentifier() would not
enforce FORCE_LONGITUDE_FIRST_AXIS_ORDER=true for this search​ 😕. Or, I now
begin to wonder, is there a reason to?
The second issue, even if I copy/paste CRS class to my module and change the
FORCE_LONGITUDE_FIRST_AXIS_ORDER flag to false, I still do not get 4647 as an
answer. I debugged it and found out, 4647 is discarded in
IdentifiedObjectFinder#createFromCodes() /
IdentifiedObjectFinder#deriveEquivalent() because its "baseCRS" ("EPSG:ETRS89")
defines northing-easting axis to be default and so does not match "exactly
(ignoring metadata)" "baseCRS" of the CRS constructed from WKT. This might be a
bug, the axis order of "baseCRS" should not matter, since it is overridden in
actual CRS anyway (always? I dont know).
With best regards, Slava
________________________________
Von: Ian Turton <[email protected]>
Gesendet: Samstag, 24. Januar 2026 13:04
An: Viatcheslav Sysoltsev <[email protected]>
Cc: [email protected]
<[email protected]>
Betreff: Re: [Geotools-gt2-users] WKT to EPSG-code: cannot make
CRS.lookupEpsgCode() to detect epsg:4647
Your data is stored in epsg:5652 - while you could alter the metadata to make
it appear to be stored in epsg:4647 it would end up in the wrong place (and
flipped through 90 degrees) - what you need to do is reproject it to epsg:4647.
The easiest way to do this is to use a ReprojectingFeatureCollection using
something like this
public static void main(String[] args) throws IOException,
NoSuchAuthorityCodeException, FactoryException {
if(args.length==0) {
System.err.println("usage: Reprojector shapefile.shp");
System.exit(1);
}
FileDataStore ds = FileDataStoreFinder.getDataStore(new File(args[0]));
SimpleFeatureCollection features = ds.getFeatureSource().getFeatures();
try(SimpleFeatureIterator itr=features.features()){
int count=0;
while(itr.hasNext()&&count++<10) {
System.out.println(((Geometry)
itr.next().getDefaultGeometry()).getCentroid());
}
}
System.out.println("");
ReprojectingFeatureCollection rfc = new
ReprojectingFeatureCollection(features, CRS.decode("epsg:3875"));
try(SimpleFeatureIterator itr=rfc.features()){
int count=0;
while(itr.hasNext()&&count++<10) {
System.out.println(((Geometry)
itr.next().getDefaultGeometry()).getCentroid());
}
}
}
Ian
On Fri, 23 Jan 2026 at 16:36, Viatcheslav Sysoltsev
<[email protected]<mailto:[email protected]>>
wrote:
Hi,
Hope someone can help me... I did get a shapefile, I believe produced by QGIS,
with .prj file:
PROJCS["ETRS_1989_UTM_Zone_N32",
GEOGCS["GCS_ETRS_1989",
DATUM["D_ETRS_1989",
SPHEROID["GRS_1980",6378137.0,298.257222101]
],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]
],
PROJECTION["Transverse_Mercator"],
PARAMETER["False_Easting",32500000.0],
PARAMETER["False_Northing",0.0],
PARAMETER["Central_Meridian",9.0],
PARAMETER["Scale_Factor",0.9996],
PARAMETER["Latitude_Of_Origin",0.0],
UNIT["Meter",1.0]
]
If I feed this WKT to the code:
CoordinateReferenceSystem crs = CRS.parseWKT(wkt);
Integer lookupResult = CRS.lookupEpsgCode(crs, true);
.. I do get number 5652, which is correct, but has northing-easting axis order
(https://epsg.io/5652). I'd rather prefer 4647, which is the same, but with
easting-northing. Is there a way to get it? I'm using gt-epsg-hsql plugin, here
is the gradle classpath:
implementation 'org.geotools:gt-api'
implementation 'org.geotools:gt-referencing'
implementation 'org.geotools:gt-main'
implementation 'org.geotools:gt-epsg-hsql'
implementation 'org.geotools:gt-coverage'
Geotools version is 34.1.
// Strange thing, if I copy-paste Implementation of CRS class and set
FORCE_LONGITUDE_FIRST_AXIS_ORDER to false, I still don't get 4647, but null.
Might it be a bug, maybe 4647 is not in the hsql database?
With best regards, Slava
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Ian Turton
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