ShapesAsWKTModule does not deserialize WKT, returns null

[electricsam]

The ShapesAsWKTModule serializes Geometry objects just fine, but it cannot deserialize them. The object returned is null.

Here is a test to demonstrate the issue:

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import org.junit.Test;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.PrecisionModel;
import org.locationtech.jts.io.ParseException;
import org.locationtech.jts.io.WKTReader;
import org.locationtech.spatial4j.io.jackson.ShapesAsWKTModule;

public class ObjectMapperConfigurationTest {

  public static class GeomWrapper {

    private Geometry geometry;

    public Geometry getGeometry() {
      return geometry;
    }

    public void setGeometry(Geometry geometry) {
      this.geometry = geometry;
    }
  }

  private static Geometry createGeometry(String wkt) throws ParseException {
    GeometryFactory geometryFactory = new GeometryFactory(new PrecisionModel(), 4326);
    WKTReader wktReader = new WKTReader(geometryFactory);
    return wktReader.read(wkt);
  }

  @Test
  public void test() throws Exception {
    final String wkt = "POINT (30 10)";
    final Geometry geometry = createGeometry(wkt);

    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.disable(MapperFeature.DEFAULT_VIEW_INCLUSION);
    objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
    objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    objectMapper.registerModule(new ShapesAsWKTModule());
    objectMapper.registerModule(new JavaTimeModule());
    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

    final GeomWrapper toSerialize = new GeomWrapper();
    toSerialize.setGeometry(geometry);
    String json = objectMapper.writeValueAsString(toSerialize);
    System.out.println(json);
    assertEquals("{\"geometry\":\"POINT (30 10)\"}", json);

    final GeomWrapper deserialized = objectMapper.readValue(json, GeomWrapper.class);
    assertNotNull(deserialized.getGeometry());
  }
}```

[dsmiley]

@jdeolive this is curious. Note that the JSON written here has a string value of a point in WKT syntax! (multi-lingual format LOL). I'm not particularly familiar with GeoJSON but that looks like a bug in writing.

I looked at the reading side in a debugger which led me to: org/locationtech/spatial4j/io/jackson/ShapeDeserializer.java:22 which calls a JsonToken.asString. but JsonToken is an enum (immutable); it doesn't have the string it's trying to get. I believe it should call jp.getValueAsString(). Of course this is even if it makes sense to embed WKT inside GeoJSON.

[jdeolive]

I guess you could call it valid JSON output but I would say it's definitely invalid GeoJSON. It's also missing a "type" property, required for valid GeoJSON output.

[dsmiley]

So then our GeoJson writing has problems?

[dsmiley]

@jdeolive I put the code here in a branch where you can easily run it.
https://github.com/locationtech/spatial4j/tree/geoJsonTroubles175