Jackson unmarshalling with Immutable objects (jackson-databind >= 2.7.6 or >= 2.8.1 or >= 2.9 or >=3)

A.java

@JsonDeserialize (builder = A.Builder.class)
public class A { private final String b; private final int c;

    @JsonPOJOBuilder (withPrefix = "")
    public static class Builder {
        private String b;
        private int    c;
                
        @Override
        public A build () {
            return new A (this.b, this.c);
        }
                
        public Builder b (final String b) {
            this.b = b;
            return this;
        }
                
        public Builder c (final int c) {
            this.c = c;
            return this;
        }
                
    }
            
    private A (final String b, final int c) {
        this.b = b;
        this.c = c;
    }
}

TripSegment.java

@JsonDeserialize (builder = TripSegment.Builder.class)
public class TripSegment { private final TripSegment.TransportMode mode; private final SegmentDetails segmentDetails;

    @JsonPOJOBuilder (withPrefix = "")
    public static class Builder {
        private TripSegment.TransportMode mode;
        private SegmentDetails segmentDetails;
                
        @Override
        public TripSegment build () {
            return new TripSegment (this.mode, this.segmentDetails);
        }
                
        public Builder mode (final TripSegment.TransportMode mode) {
            this.mode = mode;
            return this;
        }

        @JsonTypeInfo (use = JsonTypeInfo.Id.CUSTOM, include = JsonTypeInfo.As.EXTERNAL_PROPERTY, property = "mode", visible = true)
        @JsonTypeIdResolver (TripSegment.TransportMode.ModeTypeIdResolver.class)
        public Builder segmentDetails (final SegmentDetails segmentDetails) {
            this.segmentDetails = segmentDetails;
            return this;
        }
                
    }
            
    private A (final TripSegment.TransportMode mode, final SegmentDetails segmentDetails) {
        this.mode = mode;
        this.segmentDetails = segmentDetails;
    }
    
    
    public enum TransportMode { 
      FLIGHT(FlightSegmentDetails.class), 
      TRAIN(TrainSegmentDetails.class), 
      BOAT(BoatSegmentDetails.class), 
      CAR_SHARING(CarSharingSegmentDetails.class), 
      LOCAL_TRANSIT(LocalTransitSegmentDetails.class);
      
      TransportMode(Class<? extends SegmentDetails> detailsClass);
      
      <T> Class<T extends SegmentDetails> getDetailsClass () {
        return (T) detailsClass;
      }
      
      public static TransportMode fromDetailsClass (Class<? extends SegmentDetails> detailsClass) {
        for (TransportMode tm : TransportMode.values ()) {
          if (tm.getDetailsClass () == detailsClass) {
            return tm;
          }
        }
        throw new IllegalArgumentException ("not found");
      }
      
      public static class ModeTypeIdResolver implements TypeIdResolver {
            
            @Override
            public void init (JavaType baseType) {
            }
            
            @SuppressWarnings ("unchecked")
            @Override
            public String idFromValue (Object value) {
                if (! (value instanceof TripSegment)) {
                    return null;
                }
                return TransportMode.fromDetailsClass ((Class<SegmentDetails>) value.getClass ()).name ();
            }
            
            @Override
            public String idFromValueAndType (Object value, Class<?> suggestedType) {
                return this.idFromValue (value);
            }
            
            @Override
            public String idFromBaseType () {
                return null;
            }
            
            @Override
            public JavaType typeFromId (DatabindContext context, String id) throws IOException {
                return TypeFactory.defaultInstance ().constructType (TransportMode.valueOf (id).getDetailsClass ());
            }
            
            @Override
            public String getDescForKnownTypeIds () {
                return "TransportMode";
            }
            
            @Override
            public Id getMechanism () {
                return JsonTypeInfo.Id.CUSTOM;
            }
    }
}