import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import java.io.IOException;

public class NullifyingDeserializer<T> extends JsonDeserializer<T> {

    @Override
    public T deserialize(JsonParser parser, DeserializationContext context) throws IOException {
        return null;
    }
}

This is an example of a custom deserializer that simply returns null for any input. This class extends JsonDeserializer and overrides the deserialize method to return null for any input.

It is useful when you want to ignore certain fields during deserialization, you can use this deserializer to deserialize those fields and they will be ignored as they will be null.

You will need to use this deserializer along with ObjectMapper.registerModule() method to register this deserializer to be used by the ObjectMapper.