force jackson mapper to always add class type on writeValue without annotations

jackson, json

Solution

You can do that with enableDefaultTyping() of the ObjectMapper

e.g.

mapper.enableDefaultTyping(DefaultTyping.OBJECT_AND_NON_CONCRETE);

See ObjectMapper API

Problem

Is it possible to configure jackson to always add the type of the serialized object to the generated json output. For example: ``` package org.acme; class ClassA { String a; String b; } ``` and I want the generated json to be: ["org.acme.ClassA",{"a":"str1","b":"str2"}]

Original source