SpringBoot Potential Regression with Configuration Properties in Spring Boot 3.5.1

Hello,

when updating one of my applications from Spring Boot 3.5.0 to 3.5.1/3.5.2 a few testcases started to fail when loading Configuration Properties in my integration tests. It seems that when a configuration property is defined as list it does not work anymore.

I have a Configuration Property like this:

@Getter
@Setter
@Configuration
@NoArgsConstructor
@AllArgsConstructor
@ConfigurationProperties("openstack.server.os")
public class OpenStackServerOs {
  private List<Template> templates;

  /** Configuration Property for Templates */
  @Getter
  @Setter
  @NoArgsConstructor
  @AllArgsConstructor
  public static class Template {
    private String name;
    private boolean isDefault;
    private List<OperatingSystem> operatingSystem;
    private TemplateType type;
    private List<CloudInitFile> files;
  }

  public enum TemplateType {
    YML,
    MULTI_PART
  }

  /** Configuration Property for Files */
  @Getter
  @Setter
  @NoArgsConstructor
  @AllArgsConstructor
  public static class CloudInitFile {
    private String filename;
    private String contentType;

    public String getFile() {
      return filename.substring(filename.lastIndexOf('/') + 1);
    }
  }
}

This code worked so far without issues, but now causes errors. I created a small demo project - https://github.com/dietzsch/demo. When running with Spring Boot 3.5.0 the test is successful, with 3.5.1/3.5.2 is causing an error.

Alex

Comment From: philwebb

I get a 404 clicking on https://github.com/dietzsch/demo

Comment From: philwebb

@dietzsch I think this is a duplicate of #46039. We're working on another release that should be out in the next few hours.

Comment From: philwebb

@ch4mpy Did you just make and delete a comment on this issue. I was just trying to build https://github.com/ch4mpy/spring-addons but now I can't find the comment that led me to it.

Comment From: ch4mpy

Yes, I deleted it after I realised that the project kept crashing because of my attempts to hack around the regression.

Very sorry about that.

Comment From: philwebb

No worries. Quite a relief actually after all the pain of yesterdays releases :)