Why do I get the following error : Can't find a codec for class com.mongodb.client.model.geojson.Polygon

Question

I am trying to do a geospatial query using MongoDB's com.mongodb.client.model.geojson.Polygon class and com.mongodb.client.model.geojson.Position class. The client code populates the four double corners in its own boundingBox object.

Here is the code snippet:

Polygon polygon = new Polygon(Arrays.asList(new Position(boundingBox.getRightLongitude(),boundingBox.getTopLatitude()), 
                new Position(boundingBox.getLeftLongitude(), boundingBox.getTopLatitude()), 
                new Position(boundingBox.getLeftLongitude(), boundingBox.getBottomLatitude()), 
                new Position(boundingBox.getRightLongitude(), boundingBox.getBottomLatitude()),
                new Position(boundingBox.getRightLongitude(), boundingBox.getTopLatitude())));
        //Document filter = new Document("coordinates",geoWithin("coordinates", polygon));


    Block<Document> printBlock = new Block<Document>() {
         @Override
         public void apply(final Document document) {
             System.out.println(document.toJson());
         }
    };
    database.getCollection("roads").find(geoWithin("coordinates",polygon)).forEach(printBlock);

And here is the error:

Exception in thread "main" org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class com.mongodb.client.model.geojson.Polygon.

Answer 1

In your settings you need to specify the codec registry, you're currently missing GeoJsonCodecProvider() using com.mongodb.MongoClient.getDefaultCodecRegistry() should do fine

For the async driver

MongoClientSettings settings = MongoClientSettings.builder().readPreference(readPreference)
    .codecRegistry(com.mongodb.MongoClient.getDefaultCodecRegistry()).socketSettings(sockSettings)
    .connectionPoolSettings(connPoolSettings).credentialList(credentials))
    .clusterSettings(clusterSettings).build();
LOG.info("MongoClientSettings: {}, {}, {}, {}", sockSettings, connPoolSettings, clusterSettings, credentials);
MongoClient mgc = MongoClients.create(settings);

for the normal driver

MongoClientOptions settings = MongoClientOptions.builder().readPreference(readPreference)
    .codecRegistry(com.mongodb.MongoClient.getDefaultCodecRegistry()).build();
MongoClient mgc= new MongoClient(servers,credentials,settings);