ignoring calculated fields in deserialization

Question

i have a class:

class MyClass {
  @Getter
  @Setter
  int a;

  @Getter
  @Setter
  int b;

  public int getADivB() {
    return a / b;
  }
}

when serializing i need all three properties to be serialized. however if another java process is deserializing the message i would like jackson to ignore the calculated field. (not ignore it all together as with @JSONIgnore)

deserialization code is:

String json = ... //get json from message
JsonNode root = this.mapper.readTree(json);
MyClass abdiv = this.mapper.readValue(root, MyClass.class);

Answer 1

What you need is to annotate calculated property with @JsonProperty so it will look like this:

class MyClass {
  @Getter
  @Setter
  int a;

  @Getter
  @Setter
  int b;

  @JsonProperty
  public int getADivB() {
    return a / b;
  }
}

Answer 2

You can annotate your class with

@JsonIgnoreProperties(ignoreUnknown = true)

to have the property ignored by Jackson during deserialization.