Support `@PropertySource` as an attribute in `@Configuration`

[brundabharadwaj]

Enhancement request:

Proposal: Support @PropertySource as an Attribute of @Configuration

Background

Currently, in Spring, we specify external property sources using @PropertySource separately from @Configuration. This means that when defining a configuration class, we must explicitly use @PropertySource to load properties from an external file.

Example:

@Configuration
@PropertySource("classpath:application-custom.properties")
public class AppConfig {
}

However, it would be more intuitive and concise if we could define property sources directly as an attribute of @Configuration, making the configuration more self-contained.

---

Proposal

Introduce an optional attribute propertySource in @Configuration to specify external property files.

Example of the proposed approach:

@Configuration(propertySource = "classpath:application-custom.properties")
public class AppConfig {
}

Benefits:

• Reduces redundancy by allowing property source definitions within @Configuration.
• Improves readability and maintainability.
• Keeps @PropertySource optional for backward compatibility.

---

Alternative Considerations

1. Backward Compatibility: The existing @PropertySource should still be supported for cases where multiple property sources are needed.
2. Multiple Property Sources: If needed, the propertySource attribute could accept an array to support multiple files.

Would love to hear thoughts on this proposal and whether this would be a valuable addition and I am open to contribute 🚀

[jhoeller]

I'm afraid that's not where we intend to take our design there. Generally, separate concerns are often modeled as separate annotations (in Spring and for example also in JPA), and PropertySource management is not directly connected to the @Configuration stereotype itself which is primarily about @Bean method semantics.

While I see your point as an alternative design approach, it isn't actually significantly more concise than a one-line declaration of both annotations either: @Configuration @PropertySource("classpath:application-custom.properties")