Jackson ObjectMapper jsonIgnore issue

Question

I am beginner in Jackson. I am trying this -:

public class A {  
  boolean property1;
  String property2;
  // public getters and setters for both  
 }

public abstract class MixIn {
    @JsonIgnore
    boolean property1;
  }

ObjectMapper mapper = new ObjectMapper();
mapper.addMixInAnnotations(A.class, MixIn.class);  

Now,

String result = mapper.writeValueAsString(new A())

gives me result like this - {"property2" : "value"} which is correct but if try to convert the result in the object again -:

mapper.readValue(result, A.class);

I am getting property1 back object A this -:

 A {property1 : false, property2 : value}

Why is objectMapper not ignoring the property again. Note - I tried directly putting @JsonIgnore on property1 and it worked fine but I have to use MixIn for this. I had tried putting JsonIgnore on getter and setters in MixIn too but that didn't work too.

Answer 1

Ok. I got it now. @JsonIgnore means that the property won't be written in the serialized string but if any string would be deserialized the same property would have defaults which in case of a boolean is always false which I realised when I tried with adding more properties so mix-in is actually working. It's just that I thought that in some magical way it would remove the property from the object itself. (I know it's silly.)