java - Dynamic addition of fasterxml Annotation?

Question

Is there a way to set @JsonProperty annotation dynamically like:

class A {

    @JsonProperty("newB") //adding this dynamically
    private String b;

}

or can I simply rename field of an instance? If so, suggest me an idea. Also, in what way an ObjectMapper can be used with serialization?

Answer 1

Assume that your POJO class looks like this:

class PojoA {

    private String b;

    // getters, setters
}

Now, you have to create MixIn interface:

interface PojoAMixIn {

    @JsonProperty("newB")
    String getB();
}

Simple usage:

PojoA pojoA = new PojoA();
pojoA.setB("B value");

System.out.println("Without MixIn:");
ObjectMapper mapper = new ObjectMapper();
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(pojoA));

System.out.println("With MixIn:");
ObjectMapper mapperWithMixIn = new ObjectMapper();
mapperWithMixIn.addMixInAnnotations(PojoA.class, PojoAMixIn.class);
System.out.println(mapperWithMixIn.writerWithDefaultPrettyPrinter().writeValueAsString(pojoA));

Above program prints:

Without MixIn:
{
  "b" : "B value"
}
With MixIn:
{
  "newB" : "B value"
}