コーデック

public enum PowerStatus {
    ON,
    OFF
}

public class PowerStatusCodec implements Codec<PowerStatus> {
    @Override
    public void encode(BsonWriter writer, PowerStatus value, EncoderContext encoderContext) {
        if (value != null) {
            writer.writeBoolean(value.equals(PowerStatus.ON) ? Boolean.TRUE : Boolean.FALSE);
        }
    }
    @Override
    public PowerStatus decode(BsonReader reader, DecoderContext decoderContext) {
        return reader.readBoolean() ? PowerStatus.ON : PowerStatus.OFF;
    }
    @Override
    public Class<PowerStatus> getEncoderClass() {
        return PowerStatus.class;
    }
}

CodecRegistry codecRegistry = CodecRegistries.fromCodecs(new IntegerCodec(), new PowerStatusCodec());

Codec<PowerStatus> powerStatusCodec = codecRegistry.get(PowerStatus.class);
Codec<Integer> integerCodec = codecRegistry.get(Integer.class);

public class MonolightCodecProvider implements CodecProvider {
    public MonolightCodecProvider() {}
    @Override
    @SuppressWarnings("unchecked")
    public <T> Codec<T> get(Class<T> clazz, CodecRegistry registry) {
        if (clazz == Monolight.class) {
            return (Codec<T>) new MonolightCodec(registry);
        }
        // return null when not a provider for the requested class
        return null;
    }
}

BsonTypeClassMap bsonTypeClassMap = new BsonTypeClassMap();
Class<?> clazz = bsonTypeClassMap.get(BsonType.ARRAY);
System.out.println("Java type: " + clazz.getName());

Map<BsonType, Class<?>> replacements = new HashMap<BsonType, Class<?>>();
replacements.put(BsonType.ARRAY, Set.class);
BsonTypeClassMap bsonTypeClassMap = new BsonTypeClassMap(replacements);
Class<?> clazz = bsonTypeClassMap.get(BsonType.ARRAY);
System.out.println("Java type: " + clazz.getName());

public class Monolight {
    private PowerStatus powerStatus = PowerStatus.OFF;
    private Integer colorTemperature;
    public Monolight() {}
    // ...

public class MonolightCodec implements Codec<Monolight>{
    private Codec<PowerStatus> powerStatusCodec;
    private Codec<Integer> integerCodec;
    public MonolightCodec(CodecRegistry registry) {
        this.powerStatusCodec = registry.get(PowerStatus.class);
        this.integerCodec = registry.get(Integer.class);
    }
    // Defines an encode() method to convert Monolight enum values to BSON values
    @Override
    public void encode(BsonWriter writer, Monolight value, EncoderContext encoderContext) {
        writer.writeStartDocument();
        writer.writeName("powerStatus");
        powerStatusCodec.encode(writer, value.getPowerStatus(), encoderContext);
        writer.writeName("colorTemperature");
        integerCodec.encode(writer, value.getColorTemperature(), encoderContext);
        writer.writeEndDocument();
    }
    // Defines a decode() method to convert BSON values to Monolight enum values
    @Override
    public Monolight decode(BsonReader reader, DecoderContext decoderContext) {
        Monolight monolight = new Monolight();
        reader.readStartDocument();
        while (reader.readBsonType() != BsonType.END_OF_DOCUMENT) {
            String fieldName = reader.readName();
            if (fieldName.equals("powerStatus")) {
                monolight.setPowerStatus(powerStatusCodec.decode(reader, decoderContext));
            } else if (fieldName.equals("colorTemperature")) {
                monolight.setColorTemperature(integerCodec.decode(reader, decoderContext));
            } else if (fieldName.equals("_id")){
                reader.readObjectId();
            }
        }
        reader.readEndDocument();
        return monolight;
    }
    // Returns an instance of the Monolight class, since Java cannot infer the class type
    @Override
    public Class<Monolight> getEncoderClass() {
        return Monolight.class;
    }
}

public class MonolightCodecProvider implements CodecProvider {
    public MonolightCodecProvider() {}
    @Override
    @SuppressWarnings("unchecked")
    public <T> Codec<T> get(Class<T> clazz, CodecRegistry registry) {
        if (clazz == Monolight.class) {
            return (Codec<T>) new MonolightCodec(registry);
        }
        // return null when not a provider for the requested class
        return null;
    }
}

public class MonolightCodecExample {
    public static void main(String[] args) {
        String uri = "<MongoDB connection URI>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            CodecRegistry codecRegistry = CodecRegistries.fromRegistries(
                    CodecRegistries.fromCodecs(new IntegerCodec(), new PowerStatusCodec()),
                    CodecRegistries.fromProviders(new MonolightCodecProvider()),
                    MongoClientSettings.getDefaultCodecRegistry());
            MongoDatabase database = mongoClient.getDatabase("codecs_example_products");
            MongoCollection<Monolight> collection = database.getCollection("monolights", Monolight.class).withCodecRegistry(codecRegistry);
            // construct and insert an instance of Monolight
            Monolight myMonolight = new Monolight();
            myMonolight.setPowerStatus(PowerStatus.ON);
            myMonolight.setColorTemperature(5200);
            collection.insertOne(myMonolight);
            // retrieve one or more instances of Monolight
            List<Monolight> lights = new ArrayList<>();
            collection.find().into(lights);
            System.out.println(lights);
        }
    }
}