Opening of a Geojson file fails with ClassCastException

[viliam.durina@…]

What steps will reproduce the problem?

1. Open the attached geojson file

Please provide any additional information below. Attach a screenshot if possible.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2026-01-31 13:00:34 +0100 (Sat, 31 Jan 2026)
Revision:19481
Build-Date:2026-02-01 02:30:45
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (19481 en_GB) Linux Ubuntu 24.04.4 LTS
Memory Usage: 460 MB / 7888 MB (184 MB allocated, but free)
Java version: 23.0.2+7-58, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 3840x2160x[Multi depth]@60Hz (scaling 2.00×2.00)
Maximum Screen Size: 3840×2160
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_GB.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: en_GB
Numbers with default locale: 1234567890 -> 1234567890
Desktop environment: ubuntu:GNOME
libcommons-logging-java: libcommons-logging-java:all-1.3.0-1ubuntu1
fonts-noto: fonts-noto:-
VM arguments: [-Dsun.java2d.uiScale=2, --add-exports=java.base/sun.security.action=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.plugins.jpeg=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.spi=ALL-UNNAMED]
Dataset consistency test: No problems found

Plugins:
+ buildings_tools (36474)
+ conflation (277)
+ jts (36474)
+ utilsplugin2 (36474)

Last errors/warnings:
- 03570.891 E: Handled by bug report queue: java.lang.ClassCastException: class org.eclipse.parsson.JsonObjectBuilderImpl$JsonObjectImpl cannot be cast to class jakarta.json.JsonArray (org.eclipse.parsson.JsonObjectBuilderImpl$JsonObjectImpl and jakarta.json.JsonArray are in unnamed module of loader 'app')



=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: main-worker-0 (46) of main
java.lang.ClassCastException: class org.eclipse.parsson.JsonObjectBuilderImpl$JsonObjectImpl cannot be cast to class jakarta.json.JsonArray (org.eclipse.parsson.JsonObjectBuilderImpl$JsonObjectImpl and jakarta.json.JsonArray are in unnamed module of loader 'app')
	at org.eclipse.parsson.JsonObjectBuilderImpl$JsonObjectImpl.getJsonArray(JsonObjectBuilderImpl.java:229)
	at org.openstreetmap.josm.io.GeoJSONReader.parseGeometry(GeoJSONReader.java:220)
	at org.openstreetmap.josm.io.GeoJSONReader.parseFeature(GeoJSONReader.java:164)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:215)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:215)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1939)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:570)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:560)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:265)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:727)
	at org.openstreetmap.josm.io.GeoJSONReader.parseFeatureCollection(GeoJSONReader.java:149)
	at org.openstreetmap.josm.io.GeoJSONReader.parseRoot(GeoJSONReader.java:100)
	at org.openstreetmap.josm.io.GeoJSONReader.parse(GeoJSONReader.java:87)
	at org.openstreetmap.josm.io.GeoJSONReader.doParseDataSet(GeoJSONReader.java:471)
	at org.openstreetmap.josm.io.GeoJSONReader.parseDataSet(GeoJSONReader.java:536)
	at org.openstreetmap.josm.gui.io.importexport.GeoJSONImporter.parseDataSet(GeoJSONImporter.java:36)
	at org.openstreetmap.josm.gui.io.importexport.OsmImporter.loadLayer(OsmImporter.java:121)
	at org.openstreetmap.josm.gui.io.importexport.OsmImporter.importData(OsmImporter.java:97)
	at org.openstreetmap.josm.gui.io.importexport.OsmImporter.importData(OsmImporter.java:82)
	at org.openstreetmap.josm.gui.io.importexport.FileImporter.importDataHandleExceptions(FileImporter.java:103)
	at org.openstreetmap.josm.actions.OpenFileAction$OpenFileTask.importData(OpenFileAction.java:426)
	at org.openstreetmap.josm.actions.OpenFileAction$OpenFileTask.realRun(OpenFileAction.java:354)
	at org.openstreetmap.josm.gui.PleaseWaitRunnable.doRealRun(PleaseWaitRunnable.java:94)
	at org.openstreetmap.josm.gui.PleaseWaitRunnable.run(PleaseWaitRunnable.java:142)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.lang.Thread.run(Thread.java:1575)

[anonymous]

Found the root cause. It was missing coordinates at a few points, where my tool generated {}. E.g. this file fails:
`
{

"type": "FeatureCollection",
"features": [

{

"type": "Feature",
"geometry": {

"type": "Point",
"coordinates": {}

},
"properties": {
"ref:minvskaddress":"7102594532",
"addr:city":"Cífer",
"addr:place":"Cífer",
"addr:street":"Alejová",
"addr:conscriptionnumber":1466,
"addr:streetnumber":"4",
"addr:postcode":91943,
"addr:housenumber":"1466/4",
"addr:country":"SK"
}

}
]

}
`

This issue could be reported more cleanly, ideally with the line number.

[stoecker]

Milestone renamed

[stoecker]

In 19599/josm:

properly catch class cast exception in JSOn reader, fix #24658

[stoecker]

In 19600/josm:

readd vanished first line, see #24658