Migration to 3.0.0-rc1 issues

[plokhotnyuk]

I'm trying to migrate on 3.0.0-rc1 here and don't know yet how to resolve remaining issues:

1. how to enforce serialization of java.time.Year as a JSON string (not a number);
2. how to use a custom pretty printer with 2 space indention for JSON objects and JSON arrays;
3. how to avoid serialization of null values for None;
4. how to properly register classes for sum types that will use a discriminator key/value pair.

[pjfanning]

Regarding the java.time classes, have you registered the JavaTimeModule? https://github.com/FasterXML/jackson-modules-java8/tree/master/datetime

https://repo1.maven.org/maven2/tools/jackson/datatype/jackson-datatype-jsr310/3.0.0-rc1/

[pjfanning]

Actually, I found the JavaTimeModule in the changed code. Not sure why 'year' is broken. So it now appears as year: 2025 instead of year: "2025"?

[pjfanning]

I found FasterXML/jackson-modules-java8#355 for the year change.

It looks like year is now deliberately serialized as a number. There appears to be a java annotation that might make it serialize as a string.
@JsonFormat(shape = JsonFormat.Shape.STRING)

FasterXML/jackson-modules-java8@f478801#diff-2dc31f3ce21d209bc49dd1894d08b04aaf011f3a178e72503f6949bff4711cbaR31-R35

fyi @cowtowncoder

[pjfanning]

For Pretty Printer, I found a test in the master branch of jackson-databind that tests custom pretty printing. It uses

JsonMapper.builder().defaultPrettyPrinter(printer)

https://github.com/FasterXML/jackson-databind/blob/master/src/test/java/tools/jackson/databind/ObjectMapperTest.java#L200

[pjfanning]

Regarding setSerializationInclusion, I think this is the equivalent

JsonMapper.builder().changeDefaultPropertyInclusion(incl -> incl
                        .withValueInclusion(JsonInclude.Include.NON_EMPTY)
                        .withContentInclusion(JsonInclude.Include.NON_EMPTY))

https://github.com/FasterXML/jackson-databind/blob/master/src/test/java/tools/jackson/databind/ser/AnyGetterTest.java#L307-L309

[plokhotnyuk]

@pjfanning Thanks a lot for your support!

I've solved all issues except serialization of java.time.Year values. The challenge is that I cannot use annotation for a field because I need to serialize a top-level array of java.time.Year. I tried following and nothing worked for me to serialize java.timeYear values as strings:

1. jsonMapperBuilder.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
2. jsonMapperBuilder.addModule(new JavaTimeModule().enable(JavaTimeFeature.ALWAYS_ALLOW_STRINGIFIED_DATE_TIMESTAMPS))
3. jsonMapperBuilder.addModule(new SimpleModule().addSerializer(classOf[Year], { var ser: YearSerializer = null; new YearSerializer { ser = withFormat(null, false, JsonFormat.Shape.STRING) }; ser}))

[cowtowncoder]

It should be possible to associate @JsonFormat shape via "Config Overrides" for type.
Looks like test for PR has it:

FasterXML/jackson-modules-java8@dc1e77f#diff-2dc31f3ce21d209bc49dd1894d08b04aaf011f3a178e72503f6949bff4711cbaR28-R64

so something like

        final ObjectMapper asStringMapper = JsonMapper.builder()
                .withConfigOverride(Year.class, o -> o.setFormat(
                        JsonFormat.Value.forShape(JsonFormat.Shape.STRING)))
                .addModule(new JavaTimeModule())
                .build();

[plokhotnyuk]

@cowtowncoder Thank you very much! It works for me!