jackson-databind

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Describe the bug DeserializationFeature.ACCEPT_FLOAT_AS_INT does not work when floating point value is in a JSON string.

Version information 2.13.2

To Reproduce

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Foo {
    static class C {
        public int x;
    }
    public static void main(String[] args) throws JsonMappingException, JsonProcessingException {
        C a = new ObjectMapper()
            .enable(DeserializationFeature.ACCEPT_FLOAT_AS_INT)
            .readValue("{ \"x\": 123.0 }", C.class) // good
        ;
        System.out.println(a.x);
        C b = new ObjectMapper()
            .enable(DeserializationFeature.ACCEPT_FLOAT_AS_INT)
            .readValue("{ \"x\": \"123.0\" }", C.class) // bad
        ;
        System.out.println(b.x);
    }
}

Expected behavior Expected output:

123
123

Additional context Actual output:

Exception in thread "main" com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `int` from String "123.0": not a valid `int` value

Hmmh.

First of all, thank you for reporting this issue.

Not quite sure how to feel about this as it requires two coercions -- from String to Float; from Float to Int -- so not sure if this should work at all; and if so, what kind of settings should be required. (in this case I could argue that conversion is not from Float to Int but from String that is not Int to Int). My concern is that such chains of conversions/coercions can get very elaborate.

On short term it may make sense to add a custom deserializer if this functionality is needed; fix, if any, would take a while and would likely be in a new minor version.