PolymorphicTypeValidator issue

[mwxp06]

Hello,
after upgrading into Java Spring Boot 4, I upgreaded also jobrunr-spring-boot-4-starter to version 8.3.1.

From that time (due to new restriction) I am still getting error when:

Header header .....
jobScheduler.enqueue(() -> notify.header(header)

-----
@EqualsAndHashCode(callSuper = true)
@SuperBuilder
@Data
@NoArgsConstructor
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class Header extends HeaderEntity {
	HeaderCommon header;
	@Builder.Default
	List<Art> art = new ArrayList<>();
	.....
	
@EqualsAndHashCode(callSuper = true)
@SuperBuilder
@Data
@NoArgsConstructor
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class Art extends ArtEntity {
	@Builder.Default
	List<Location> loc = new ArrayList<>();
}
......
@SuperBuilder
@Data
@NoArgsConstructor
@AllArgsConstructor
@JsonInclude(JsonInclude.Include.NON_NULL)
public class ArtEntity {
	private String uuid; 
	private String country;
	...

Error message:

Could not resolve type id 'com.comp.dto.Art' as a subtype of java.lang.Object: 
Configured PolymorphicTypeValidator (of type tools.jackson.databind.jsontype.BasicPolymorphicTypeValidator) denied resolution 
at [Source: REDACTED (StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION disabled); byte offset: #UNKNOWN] (through reference chain: java.util.ArrayList[0])

Can I somehow allow polymorphic / tell jobrunr that source object is not interface, to solve this issue?

I tried specify my own JsonMapper, but this influence all mapping, not just jobrunr..

Thank you for your advice

[auloin]

Hi @mwxp06,

I don't have the full details but I believe this exception is coming from Jackson 3 not allowing polymorphic serialization by default. There is also little docs on how to configure things with Jackson 3...

By default spring boot 4 comes with Jackson 3, so it's also the default JsonMapper JobRunr configures.

A few options below, could you let me know what works for you as we're also in the process of documenting these?

Use JsonTypeInfo

EDIT: this doesn't work JsonTypeInfo as no say in the type validation (at the time of writing that is).

Annotating your polymorphic classes with @JsonTypeInfo may still work: https://stackoverflow.com/a/31666888, https://github.com/FasterXML/jackson-docs/wiki/JacksonPolymorphicDeserialization#12-per-class-annotations

Replace the default JsonMapper bean

EDIT: this doesn't work, JobRunr will overwrite it. An alternative solution is offered by #1458.

@Bean
public JsonMapper jobRunrJsonMapper() {
     var typeValidator = BasicPolymorphicTypeValidator.builder()
                    .allowIfSubType(MyClass.class)
                    .build();
     var jacksonJsonBuilder = tools.jackson.databind.json.JsonMapper
                    .builder()
                    .activateDefaultTypingAsProperty(typeValidator, DefaultTyping.OBJECT_AND_NON_CONCRETE, "@class");
     return new Jackson3JsonMapper(jacksonJsonBuilder);
}

Stay on Jackson 2

If the upgrade to Jackson 3 is not intentional, you can follow Spring's migration guide on how to stay on Jackson 2: https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-4.0-Migration-Guide#jackson-2-compatibility

---

In any case, we appreciate any feedback, as this is also new to us.

---

A little feedback on our end: we generally recommend to use small job arguments whenever possible, instead of a full entity object, it's preferable to pass an identifier as the job argument.

[auloin]

rest api returns mess now, if there is public JsonMapper jobRunrJsonMapper2()

@mwxp06 what's the expected vs observed behaviour, in other words any examples of what you consider a mess and what it should be instead?

[mwxp06]

Please run my example and you will see in a moment where is a problem..

Anyway:
With own JsonMapper - which not helped:

Without - expected correct output:

[auloin]

See below is configuring Jackson's JsonMapper not JobRunr's JsonMapper. The import is import tools.jackson.databind.json.JsonMapper; instead of import org.jobrunr.utils.mapper.JsonMapper;. This explains why your RestController is giving you a "messy" result.

That being said, I'm surprised @JsonTypeInfo isn't working, my understanding of the documentation of this method https://github.com/FasterXML/jackson-databind/blob/3.x/src/main/java/tools/jackson/databind/cfg/MapperBuilder.java#L1667-L1687 is that, that should be enough for polymorphic deserialization. I'd like to invite you to ask for clarifications from https://github.com/FasterXML/jackson-databind/discussions.

What we can do on JobRunr's side is to allow people to provide their own polymorphic type validation via BasicPolymorphicTypeValidator.Builder. But then you'd need to provide a org.jobrunr.utils.mapper.JsonMapper bean. Far from ideal, but the only solution I can think of.

package com.example.testjobrunr;

import org.jobrunr.jobs.mappers.JobMapper;
import org.jobrunr.storage.InMemoryStorageProvider;
import org.jobrunr.storage.StorageProvider;
import org.jobrunr.utils.mapper.jackson3.Jackson3JsonMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import tools.jackson.databind.DefaultTyping;
import tools.jackson.databind.json.JsonMapper;
import tools.jackson.databind.jsontype.BasicPolymorphicTypeValidator;

@Configuration
public class JobRunrConfiguration {

	@Bean
	public StorageProvider storageProvider(JobMapper jobMapper) {
		InMemoryStorageProvider storageProvider = new InMemoryStorageProvider();
		storageProvider.setJobMapper(jobMapper);
		return storageProvider;
	}

	@Bean
	public JsonMapper jobRunrJsonMapper2() {
		var typeValidator = BasicPolymorphicTypeValidator.builder()
			.allowIfSubType("com.example.testjobrunr")
				.build();
		var jacksonJsonBuilder = tools.jackson.databind.json.JsonMapper
				.builder()
				.activateDefaultTypingAsProperty(typeValidator, DefaultTyping.OBJECT_AND_NON_CONCRETE, "@class");
		return new JsonMapper(jacksonJsonBuilder);
	}

}

The return type here is wrong, additionally, the bean method name should be jobRunrJsonMapper for the default to be replaced by Spring.

[mwxp06]

Probably I found the reason..
In your Jackson3JsonMapper you are allowing only:
.allowIfSubType("org.jobrunr.").allowIfSubType("java.nio.").allowIfSubType("java.util.concurrent.").allowIfSubTypeIsArray()

But because I am using List not ArrayList - getting polymorf error, because List is not allowed (ArrayList works fine).

I try to add my own mapper:

@Bean
    public JsonMapper jobRunrJsonMapper() {
        var typeValidator = BasicPolymorphicTypeValidator.builder()
                .allowIfSubType("com.example.testjobrunr.")
                .allowIfSubType("org.jobrunr.")
                .allowIfSubType("java.nio.")
                .allowIfSubType("java.util.")
                .allowIfSubTypeIsArray()
                .build();

        var jacksonJsonBuilder = tools.jackson.databind.json.JsonMapper
                .builder()
                .activateDefaultTypingAsProperty(typeValidator, DefaultTyping.OBJECT_AND_NON_CONCRETE, "@class");
        return new Jackson3JsonMapper(jacksonJsonBuilder);
    }

But unfortunatelly is overwrite by your default..

Please can you try to allow .allowIfSubType("java.util.") as well? This probably solve the issue.

Thank you very much for your help

[auloin]

But unfortunatelly is overwrite by your default..

This is solved in #1458

Please can you try to allow .allowIfSubType("java.util.") as well? This probably solve the issue.

If anything we should make our default even stricter IMO. We could follow Spring Security's lead and allow some java collections by default: https://github.com/spring-projects/spring-security/blob/main/core/src/main/java/org/springframework/security/jackson/CoreJacksonModule.java#L84-L97.

[auloin]

For anyone interested in this, JobRunr 8.4.0 allows to provide custom a custom polymorphic type validator. The how is documentated at https://www.jobrunr.io/en/documentation/serialization/jackson3/#allowing-polymorphic-type-deserialization-with-jackson-3.

Alternatively, you can also read on how to avoid the need for custom type validation: https://www.jobrunr.io/en/documentation/serialization/jackson3/#exploring-alternatives-to-additional-polymorphic-type-validation.

[mwxp06]

Thank you, my problem are solved in new release!!

@Bean
public Jackson3JsonMapper jobRunrJsonMapper() {
    var typeValidator = BasicPolymorphicTypeValidator.builder()
            .allowIfSubType("java.util.")
            .allowIfSubTypeIsArray();

    return new Jackson3JsonMapper(typeValidator);
}