Is it possible to deserialize values missing from JSON to some default values?

Question

As an example class:

@Getter @Setter
public static class SomeClass {
    private String notNull;
    private String nullSetEmpty;
    private String notExists;
}

Deserialization of null values to empty is possible by overriding configuration, like:

String json = " {\"notNull\": \"a value\", \"nullSetEmpty\": null}";
ObjectMapper om = new ObjectMapper();
om.configOverride(String.class)
    .setSetterInfo(JsonSetter.Value.forValueNulls(Nulls.AS_EMPTY));
SomeClass sc = om.readValue(json, SomeClass.class);
System.out.print(om.writerWithDefaultPrettyPrinter().writeValueAsString(sc));

This produces:

{
 "notNull" : "a value",
 "nullSetEmpty" : "",
 "notExists" : null
}

But how about this notExists . It is possible to add default value to each class having the problem but is there any generic way to do that like configOverride does so that Jackson handles that?

Answer 1

you can just define default value in your data class

@Getter
    @Setter
    public static class SomeClass {
        private String notNull;
        private String nullSetEmpty;
        private String notExists = "default-value";
    }