2.15.0 breaking behaviour change for records and Getter Visibility

[matteobertozzi]

In 2.15 trying to encode records with PropertyAccessor.GETTER = Visibility.NONE will result in an empty object {}.

record DataObject (int a, int b) {}

@Test
public void testRecord() throws Exception {
    final ObjectMapper jsonMapper = new JsonMapper();
    final String r = jsonMapper.writeValueAsString(new DataObject(2, 3));
    jsonMapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);
    jsonMapper.setVisibility(PropertyAccessor.GETTER, Visibility.NONE);
    Assertions.assertEquals("{\"a\":2,\"b\":3}", r); // we get {}
}

to resolve that we can set PropertyAccessor.GETTER = Visibility.DEFAULT or others, but that will break every single class serialization that does not have annotations on getter methods.

public class Foo {
    private final int x = 2;
    public int getComputedValue() { return 11; }
}

jsonMapper.writeValueAsString(new Foo()) // { x: 2, computedValue: 11 }

The behaviour in 2.14 with PropertyAccessor.GETTER = Visibility.NONE is the expected one, with records able to serialize all fields

Is this change something done on purpose? are there alternatives to set the visibility of getters and annotate every class method?

[cowtowncoder]

Wrong repo, moving.

[cowtowncoder]

@matteobertozzi We publish RC versions -- 2.15.0-rc1, rc2, rc3 -- to find these kinds of concerns; cases that are not supported explicitly (there not being unit tests to cover). So one way to think of it is that unless we test something, and no one contributes tests, feature is not formally supported.

This does not mean that usage might not be intended to work: there are gaps.

Having said that, I think I agree that if Field visibility is set to Any, it would seem serialization should consider these fields.

I am guessing #3894 would solve this issue?

[matteobertozzi]

i'm really sorry to have not tested the RCs.

#3894 should solve this one

Thank you!

[yihtserns]

@matteobertozzi can you share the reason for that config? Is the reason the same as #3628?

[matteobertozzi]

@yihtserns the main reason is because we have "bad code". with classes that contains methods called "getXyz()" but they are not getters and they are doing computations and maybe some business logic.

so if we use something different from .GETTERS = Visbility.NONE, we end up with a value that is not supposed to be serialized and maybe some business logic triggered.

public class Foo {
    private final int x = 2;
    public int getComputedValue() { return 11; }
}

jsonMapper.writeValueAsString(new Foo()) // { x: 2, computedValue: 11 }

going around all the methods in the codebase to add annotations may be fine for a major (e.g. the 3.x) but we didn't expect that for a minor.

[cowtowncoder]

@matteobertozzi Sorry did not mean that you specifically should have tested, just that it is too bad no one with this use case had tried it and reported. There are gaps, hopefully over time fewer and fewer.

So this is a surprise to us and not a planned behavioral change.

[agavrilov76]

It is probably related that since version 2.15 MapperFeature.SORT_PROPERTIES_ALPHABETICALLY is not longer respected by record method based JSON properties.

The property 'a' in the example below comes at the last place:

    final var mapper =
        Jackson.mapperBuilder()
            .enable(SerializationFeature.INDENT_OUTPUT)
            .enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY)
            .build();

    record R(String c, String b, String e) {

      @JsonProperty
      String a() {
        return "4";
      }
    }

    System.out.println(mapper.writeValueAsString(new R("1", "2", "3")));

Output:

{
"b" : "2",
"c" : "1",
"e" : "3",
"a" : "4"
}

[yihtserns]

@agavrilov76 can you create another issue for that? It's not related to this, but rather is caused by #3724.

[agavrilov76]

@yihtserns #3900

[cowtowncoder]

Would #3894 fix solve this as well? I just merged the fix.

[matteobertozzi]

Hi, I did run my tests with the 2.15.1-20230504.033533-11 SNAPSHOT
#3894 seems to solve this issue!

Thanks!

<repositories>
    <repository>
      <id>oss.sonatype.snapshots</id>
      <url>https://oss.sonatype.org/content/repositories/snapshots</url>
      <snapshots>
        <enabled>true</enabled>
      </snapshots>
    </repository>
  </repositories>

  <properties>
    <jackson.version>2.15.1-SNAPSHOT</jackson.version>
...

[cowtowncoder]

Thank you @matteobertozzi !

[haraldk]

I just discovered that the default mapper configuration for the Azure SDK for Java is:

        .visibility(PropertyAccessor.FIELD, Visibility.ANY)
        .visibility(PropertyAccessor.GETTER, Visibility.NONE)

Upgrading jackson-databind to 2.15.0 did break my message serialization in Azure Service Bus... Was about to file a new issue, when I found this. Indeed, 2.15.1-SNAPSHOT does seem to restore things to how it worked in 2.14.2 again. 👍🏻