@JsonProperty in @JsonCreator is conflicting with POJOs getters/attributes @JsonProperty - used to work with 1.9.11

[fabienrenaud]

Note: See my second post below for the actual problem and repro.

Example of POJO:

class Foo {
    @JsonProperty("s")
    private String str;

    Foo() {

    }

    Foo(String s) {
        this.str = str;
    }

    public String getStr() {
        return str;
    }
}

and this doesn't help:

        mapper.disable(
            MapperFeature.AUTO_DETECT_CREATORS,
            MapperFeature.AUTO_DETECT_FIELDS,
            MapperFeature.AUTO_DETECT_GETTERS,
            MapperFeature.AUTO_DETECT_IS_GETTERS,
            MapperFeature.AUTO_DETECT_SETTERS,
            MapperFeature.USE_GETTERS_AS_SETTERS
        );

Even disabling DEFAULT_VIEW_INCLUSION doesn't help.

Give an exception like:
java.lang.IllegalStateException: Conflicting/ambiguous property name definitions (implicit name 'rewards'): found multiple explicit names: [s, str], but also implicit accessor: [method Foo#getStr(0 params)][visible=true,ignore=false,explicitName=false]

[cowtowncoder]

I don't think example above is complete: it won't reproduce the reported issue. Would it be possible to include more complete example to show what is actually happening?
For what it is worth, DEFAULT_VIEW_INCLUSION is not relevant here (it only affects inclusion in JSON Views, when serializing, which occurs later than property introspection).

Exception suggests that there is an ambiguity in resolving what is the actual name to use, and that there are multiple explicit annotations giving conflicting names to things that are linked together be implicit names.

[fabienrenaud]

Full executable repro :)

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;

public class JsonBug2 {

    public static void main(String[] args) throws IOException {
        final ObjectMapper mapper = new ObjectMapper();

        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

        mapper.disable(
                MapperFeature.AUTO_DETECT_CREATORS,
                MapperFeature.AUTO_DETECT_FIELDS,
                MapperFeature.AUTO_DETECT_GETTERS,
                MapperFeature.AUTO_DETECT_IS_GETTERS,
                MapperFeature.AUTO_DETECT_SETTERS,
                MapperFeature.USE_GETTERS_AS_SETTERS
        );

        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

        Foo data = mapper.readValue("{\"str\":\"the string\"}", Foo.class);
        if (data == null) {
            throw new IllegalStateException("data is null");
        }
        if (!"the string".equals(data.str)) {
            throw new IllegalStateException("bad value for data.str");
        }
    }

    private static final class Foo {

        private String str;

        @JsonCreator
        public Foo(@JsonProperty("str") String str) {
            this.str = str;
        }

        @JsonProperty("s")
        public String getStr() {
            return str;
        }

    }
}

Executing the above code will give me the following exception:

Exception in thread "main" java.lang.IllegalStateException: Conflicting/ambiguous property name definitions (implicit name 'str'): found multiple explicit names: [str, s], but also implicit accessor: [field JsonBug2$Foo#str][visible=false,ignore=false,explicitName=false]
at com.fasterxml.jackson.databind.introspect.POJOPropertyBuilder._explode(POJOPropertyBuilder.java:873)
at com.fasterxml.jackson.databind.introspect.POJOPropertyBuilder.explode(POJOPropertyBuilder.java:857)
at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._renameProperties(POJOPropertiesCollector.java:753)
at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.collect(POJOPropertiesCollector.java:246)
at com.fasterxml.jackson.databind.introspect.BasicClassIntrospector.collectProperties(BasicClassIntrospector.java:142)
at com.fasterxml.jackson.databind.introspect.BasicClassIntrospector.forDeserialization(BasicClassIntrospector.java:81)
at com.fasterxml.jackson.databind.introspect.BasicClassIntrospector.forDeserialization(BasicClassIntrospector.java:11)
at com.fasterxml.jackson.databind.DeserializationConfig.introspect(DeserializationConfig.java:550)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:323)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:261)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:241)
at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:381)
at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:3154)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3047)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2146)
at JsonBug2.main(JsonBug2.java:28)

[cowtowncoder]

Thanks! I will have to think about this a bit, to figure out whether this works as expected, or if it is a bug.
And even if "works as expected" it could still be something to improve upon.

The main question here is whether implicit name of 'str' creator argument is known; it appears it might be, because that's what is indicates as ambiguous (creator parameter "renamed" as 'str'; getter-induced property renamed as "s"). But then again, unless field is detected, things should be fine, because all accessors are explicitly renamed, and no ambiguity should exist.

So I guess it looks like this could be considered a bug.

One last thing: is this with 2.4.2? I am asking since there have been a few fixes since 2.3.

[fabienrenaud]

Yes, this is version 2.4.2.

The feature is basically meant to reformat your json, likely to condense the keys.
For example, a json file that had to be hand written or written in a human readable format would use the @JsonCreator to initialize the class...
Then annotations on attributes or getters would be used to generate the condensed output.

What's annoying is that it used to work with 1.9.11.

And this is a totally blocking issue for me. Impossible to upgrade.

[cowtowncoder]

Yes, I think the visibility (or rather, lack thereof) of field str was not properly considered here.
Fixed so that test passes (and no new test failures caused).

[fabienrenaud]

I'm confused. What is the milestone for this? 2.4.3 or 2.5?
Edit: I don't see it fixed in 2.4.3.

[cowtowncoder]

It should be included in 2.4.3, as per release notes. Are there failing unit tests to show what is not working?

[fabienrenaud]

I tried to upgrade to 2.4.3 yesterday and i still had some UT failing around that 'strange' @JsonCreator...
Gonna try to find a repro example with 2.4.3 to post here.