How to make Jackson ignore the serialization of field b if field a is false when serializing

Question

When using jackson serialization, field b is ignored when field a is false

public class MyClass {
    private boolean a;
    private int b;
}

I haven't found a solution yet，Trying to use @JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = AlarmConfig.TrueFilter.class) only works for single field

This is just a bad idea. Instead, set `b` to `null` and have Jackson ignore null values instead. Added bonus: You probably won't even need `a` at all any more (just check `b != null`) — Jorn, Jul 18 '23 at 11:13
You can try to use `@JsonAnyGetter` annotation and implement a method which checks any conditions and return as many different fields as you want. Take a look on this example [Jackson diffrent name base of other field value](https://stackoverflow.com/a/75044947/51591) — Michał Ziober, Jul 18 '23 at 23:00

score 0 · Answer 1 · answered Jul 18 '23 at 09:02

You may create your own serializer, something like:

public class MyClassSerializer extends JsonSerializer<MyClass> {

    @Override
    public void serialize(MyClass value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        gen.writeStartObject();
        gen.writeBooleanField("a", value.isA());
        if (value.isA()) {
            gen.writeNumberField("b", value.getB());
        }
        gen.writeEndObject();
    }
}

and use it like:

@JsonSerialize(using = MyClassSerializer.class)
public class MyClass { ... }

Is there any way to make it more general? – MiaoZi Jul 18 '23 at 09:04 — MiaoZi, Jul 18 '23 at 09:04

How to make Jackson ignore the serialization of field b if field a is false when serializing

1 Answers1