Stop accepting ordinal values of enum in json parsing using jackson

Question

I am trying to build json parser using jsckson. Below is my code of enum class:

public enum Priority {
    @JsonProperty("LOW")
    LOW(100),
    @JsonProperty("MEDIUM")
    MEDIUM(200),
    @JsonProperty("HIGH")
    HIGH(300);

    private int priority;

    Priority(int i) {
        this.priority = i;
    }

    public int getPriority() {
        return priority;
    }
}

Now I am expecting my parser to take only 3 inputs which are "HIGH", "LOW" and "MEDIUM". But it is taking the ordinal values also. For example: If my input is like:

{
    "priority": 0
}

It is taking LOW priority instead of giving error.

How can I stop this?

Answer 1

Add the following Bean Config:

@Bean
public Jackson2ObjectMapperBuilderCustomizer enableFailOnNumbersForEnums() {
        return jacksonObjectMapperBuilder -> jacksonObjectMapperBuilder.featuresToEnable(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS);
    }

This will stop Jackson from deserializing ordinals into Enum values. You can read more on available features to enable/disable here: https://github.com/FasterXML/jackson-databind/wiki/Deserialization-Features

Answer 2

You can also configure ObjectMapper which worked in my case:

@Configuration
public class ObjectMapperConfiguration {
    @Bean
    public ObjectMapper objectMapperBean() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS, true);

        return mapper;
    }
}

The results are the same - Jackson no longer accepts ordinal values of an enum.