Immutable/polymorphic POJO <-> JSON serialization with Jackson

Question

I\'m trying to serialize a immutable POJO to and from JSON, using Jackson 2.1.4, without having to write a custom serializer and with as few annotations as possible. I also like

Answer 1

Have a look at Genson library some of its key features are adressing your exact problem: polymorphism, not requiring annotations and most important immutable pojos. Everything works in your example with 0 annotations or heavy conf.

Genson genson = new Genson.Builder().setWithClassMetadata(true)
                            .setWithDebugInfoPropertyNameResolver(true)
                            .create();

String jsonCircle = genson.serialize(circle);
String jsonRectangle = genson.serialize(rectangle);

System.out.println(jsonCircle); // {"@class":"your.package.Circle","radius":123}
System.out.println(jsonRectangle); // {"@class":"your.package.Rectangle","w":20,"h":30}

// Throws nothing :)
Shape newCircle = genson.deserialize(jsonCircle, Shape.class);
Shape newRectangle = genson.deserialize(jsonRectangle, Shape.class);

Genson gives you also the ability to use aliases (used instead classes names).

new Genson.Builder().addAlias("shape", Shape.class)
                .addAlias("circle", Circle.class)
                .create();