Unlock SpringBoot 3.3.0: Adding Descriptions to Record Components via Configuration Metadata

Environment

SpringBoot 3.3.0 was released on May 23, 2024. The release adds a single new feature—support for describing record components in configuration metadata—along with numerous bug fixes.

1. Update Content

The new feature adds support for the record component description in the generation of configuration metadata.

1.1 Configuration Metadata

SpringBoot JARs contain a META-INF/spring-configuration-metadata.json file that lists all supported configuration properties, groups, and hints. IDEs use this file to provide context help and code completion for application.properties or application.yml .

Typical JSON structure:

<code>{
  "groups": [
    {
      "name": "server",
      "type": "xxx.ServerProperties",
      "sourceType": "xxx.ServerProperties"
    },
    ...
  ],
  "properties": [
    {
      "name": "server.port",
      "type": "java.lang.Integer",
      "sourceType": "xxx.ServerProperties"
    },
    ...
  ],
  "hints": [
    {
      "name": "spring.jpa.hibernate.ddl-auto",
      "values": [
        {"value": "none", "description": "Disable DDL handling."},
        ...
      ]
    }
  ]
}
</code>

The file enables IDE hints, as shown in the screenshots.

2. Practical Example

2.1 Environment Preparation

Add the configuration processor dependency so SpringBoot can generate the metadata file automatically:

<code>&lt;dependency&gt;
  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
  &lt;artifactId&gt;spring-boot-configuration-processor&lt;/artifactId&gt;
  &lt;optional&gt;true&lt;/optional&gt;
&lt;/dependency&gt;
</code>

2.2 Custom Configuration Properties (Java Class)

Create a POJO annotated with @Component and @ConfigurationProperties :

<code>@Component
@ConfigurationProperties(prefix = "pack.app1")
public class CommonProperties {
  private String version;
  private String title;
  private Integer numbers;
  // getters, setters
}
</code>

Corresponding YAML configuration:

<code>pack:
  app1:
    title: xxx项目
    version: 1.0.0
    numbers: 1
</code>

After building, spring-configuration-metadata.json is generated. Initially, description fields are missing for some JPA properties.

Adding Javadoc comments to each field adds description information to the metadata:

<code>/**
 * Application version
 */
private String version;
/**
 * Project title
 */
private String title;
/**
 * Number of releases
 */
private Integer numbers;
</code>

Rebuilding shows the descriptions appear in IDE hints.

2.3 Using Record Component

Java records can also be used as configuration properties:

<code>@Component
@ConfigurationProperties(prefix = "pack.app")
public record AppProperties(
    String version,
    String title,
    Integer numbers
) {}
</code>

Configuration file:

<code>pack:
  app:
    title: xxx项目
    version: 1.0.0
    numbers: 1
</code>

Generated metadata lacks description because record fields do not inherit Javadoc from the record components.

2.4 SpringBoot 3.3.0 New Feature for Records

From version 3.3.0, you can provide description for each record component using Javadoc @param tags at the class level:

<code>/&#**
 * @param version 1.1.3
 * @param title   XXXOOO项目标题
 * @param numbers 第3次发版
 *&#/
 @Component
 @ConfigurationProperties(prefix = "pack.app")
 public record AppProperties(
     String version,
     String title,
     Integer numbers
 ) {}
</code>

After rebuilding, the generated spring-configuration-metadata.json includes the description information for the record components.

Conclusion

The new SpringBoot 3.3.0 feature enables developers to add descriptive metadata to record‑based configuration properties, improving IDE assistance and documentation quality.