Add ability to amend trusted classes in Jackson2ExecutionContextStringSerializer

[fmbenhassine]

This PR is for #3765. It adds the ability to specify additional trusted classes (at construction time of the Jackson2ExecutionContextStringSerializer) without having to provide a custom object mapper.

The usage of varargs in the constructor of Jackson2ExecutionContextStringSerializer makes the change backward compatible with 4.2.

[fprochazka]

This looks like it solves it for me. It's still not very easy to replace the service itself (Jackson2ExecutionContextStringSerializer), but now at least I don't have to copy&paste the entire class. Thanks!

[nstdio]

@benas Seems this change is not binary compatible with client compiled against 4.2.x.

[fmbenhassine]

@nstdio This enhancement/feature has not been backported to 4.2.x, even though my initial comment implies it. We typically backport bug fixes only to patch releases of previous supported lines (4.2.x is approaching its EOL anyway). Anything preventing you from upgrading to 4.3?

[nstdio]

@benas Thanks for your response. Great work! We already upgraded to 4.3 with minimal effort.

The issue was that internal library was compiled against 4.2.x. After upgrading to Spring Batch version to 4.3 in the consumer project, we've got java.lang.NoSuchMethodError. The runtime cannot find the Jackson2ExecutionContextStringSerializer.<init>() method, because in 4.3 constructor signature was changed.

[duthng]

Hello @benas!

thank you for the effort putting this so far, I would like to ask, how is that possible to return a customized Jackson2ExecutionContextStringSerializer, and this Serializer will be used in default spring-batch configuration? Until now we don't have explicit configuration for JobRepository and maybe others related classes (Beans).

For example would below code would work?

@Configuration
public class SpringBatchAdditinalConfiguration {

  @Bean
  public Jackson2ExecutionContextStringSerializer jackson2ExecutionContextStringSerializer (
      return new Jackson2ExecutionContextStringSerializer("my.Class1", "my.Class2");
  }
}

If it would be not possible the which classes (JobExplorer, JobRepository ?) should I explicitly create. Do you have an example how to just only overwrite Jackson2ExecutionContextStringSerializer, but leave everything else (i.e. JobExplorer, JobRepository) with least changes as possible?

Kind regards
Thanh

[fmbenhassine]

@dthng You need to provide a custom BatchConfigurer and override getJobRepository(), see Configuring a JobRepository. You can set your custom serializer on the factory bean used to create the job repository (same approach for the job explorer if needed).