Jackson: Is there a way to ignore 0/1 on Boolean deserialization?

I. Medina :

I have a JSON object with a Boolean property that needs to allow only true or false during the deserialization.

Any value different of true and false should throw an exception.

How can I do that?

---

e.g.:

Valid json:

{
  "id":1,
  "isValid":true
}

Invalid json:

{
  "id":1,
  "isValid":1
}

---

Update

I tried what @Michał Ziober proposed and it worked fine.

As I'm implementing a Spring application (with Webflux) I just had to configure in a different way. I'm posting here what I did:

• Create a Configuration class extending from DelegatingWebFluxConfiguration
• Override the configureHttpMessageCodecs method setting the property on ObjectMapper

@Configuration
public class JacksonConfig extends DelegatingWebFluxConfiguration {

    @Override
    protected void configureHttpMessageCodecs(ServerCodecConfigurer configurer) {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.disable(MapperFeature.ALLOW_COERCION_OF_SCALARS);
        objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

        configurer.defaultCodecs()
                .jackson2JsonDecoder(new Jackson2JsonDecoder(objectMapper));
    }
}

Michał Ziober :

You need to disable ALLOW_COERCION_OF_SCALARS feature:

import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        File jsonFile = new File("./resource/test.json").getAbsoluteFile();

        ObjectMapper mapper = new ObjectMapper();
        mapper.disable(MapperFeature.ALLOW_COERCION_OF_SCALARS);

        System.out.println(mapper.readValue(jsonFile, Pojo.class));
    }
}

class Pojo {

    private int id;
    private Boolean isValid;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public Boolean getIsValid() {
        return isValid;
    }

    public void setIsValid(Boolean valid) {
        isValid = valid;
    }

    @Override
    public String toString() {
        return "Pojo{" +
                "id=" + id +
                ", isValid=" + isValid +
                '}';
    }
}

Above code prints:

Exception in thread "main" com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot coerce Number (1) for type java.lang.Boolean (enable MapperFeature.ALLOW_COERCION_OF_SCALARS to allow) at [Source: (File); line: 3, column: 14] (through reference chain: Pojo["isValid"]) at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)