Jackson serialization outputting two json rows for one java variable

I have a strange problem as I'm migrating code from Java 8 and Sprint Boot 1.X to 11 and 2.X. Previously, I discovered that Jackson was serializing private boolean isAvailable to both available: false and isAvailable: false. To add more confusion, Lombok is along for the ride so I don't have visibility on the getter and if that's causing a conflict. Below is the Java class code:

@Data
public class Availability{

    @JsonProperty("isAvailable")
    private boolean isAvailable;

}

And the reulsting JSON from the Jackson Object mapper was:

"Availability" : [{
          "isAvailable" : false,
          "available" : false }]

This was with Jackson 2.8. Now with Jackson 2.10, I am only getting isAvailable: false as the output in the JSON from the ObjectMapper.

"Availability" : [{
          "isAvailable" : false }]

It makes sense to me that it should match the Java variable name only, but the contract sadly has both versions, and I don't want to change the contract. Some are using the is, and some are not. I know a custom serializer is possible, but not sure how to do that or if it's necessary.

It's lombok + the field, interacting.

Let's take this hypothetical class (no lombok, or for that matter jackson involved at all here):

class Example {
    public boolean isAvailable() {
        return true;
    }
}

As per the beanspec, the Example class has a single read-only bean property of type boolean called available. That's because any no-args method that returns boolean and starts with is (and then a capital), counts as an accessor, and to get to the name of it, strip the is off.

So that's looking at it from that end. Now let's look at it from the other end, you writing a class where for whatever reason you've decided that the field is to be named isAvailable. The real question is: What do you want the 'property' to be named (as per beanspec)? If it really is to be called isAvailable, there's only one way to accomplish that:

class Example {
    public boolean isIsAvailable() {
        return true;
    }
}

Yes, isIsAvailable. Looks daft, but, that's what the rules decree if you want the property itself to called isAvailable. Lombok decided (SOURCE: I am a core contributor) that nobody really wants a method named isIsAvailable when you stick a @Getter annotation on a field named isAvailable.

So, now you have a class that effectively looks like, as far as jackson is concerned:

class Availability {
    @JsonProperty("isAvailable") private boolean isAvailable;

    public boolean isAvailable() { return this.isAvailable; }
}

Using no particular intelligence, just applying the literal rules, means that Jackson says: Okay, there are 2 different properties here, available (obtained by invoking isAvailable()), and the isAvailable field. For beanspec-style getters, is/get is stripped off, for fields it's not, especially if you stick a @JsonProperty("isAvailable") on there.

That's the context for why this is all happening.

A solution could be to make this method:

@JsonProperty("available")
public boolean getAvailable() { return this.available; }

I think that'll get you both variants in your JSON output.