The @ConfigurationProperties annotation injects null values when decorates a @Bean method in a @Configuration class

[igarciaes]

Hi,
The ConfigurationProperties annotation injects null values when is used to decorate a Bean method in a Configuration class. I have forked the repository and added an example bean which is configured using the configuration properties annotation. The bean values are populated correctly using only Spring Boot dependencies but the bean configuration properties are populated with null values when Micronaut is used. Here is the commit with the example:
igarciaes@1fb0d4b
I am missing something?
Thanks!

[graemerocher]

We don't currently support returning @ConfigurationProperties from a @Configuration method. You would need to define the @ConfigurationProperties on the class itself

[igarciaes]

Ok, thanks @graemerocher for your quick reply.
Then, if is not possible to use the @ConfigurationProperties annotation for bean factory methods in a @Configuration annotated class, could you please describe which would be the code refactoring using Micronaut for cases where the configuration values are injected directly to the bean returned by a factory method:

@Bean
@Primary
@ConfigurationProperties(prefix="spring.datasource")
public DataSource primaryDataSource() {
    return DataSourceBuilder.create().build();
}

@Bean
@ConfigurationProperties(prefix="spring.secondDatasource")
public DataSource secondaryDataSource() {
    return DataSourceBuilder.create().build();
}

We would like to use Micronaut for existing Spring Boot microservices and we would like to estimate the refactoring cost if needed.

Thanks in advance!

[graemerocher]

Since Micronaut does things at compilation time. You have a couple of options.

1. You can subclass the external class. See https://github.com/micronaut-projects/micronaut-sql/blob/master/jdbc-dbcp/src/main/java/io/micronaut/configuration/jdbc/dbcp/DatasourceConfiguration.java for an example of that
2. You can use @ConfigurationBuilder to reference an external builder. See https://github.com/micronaut-projects/micronaut-neo4j/blob/master/neo4j-bolt/src/main/java/io/micronaut/configuration/neo4j/bolt/Neo4jBoltConfiguration.java#L60 for an example of that

[igarciaes]

Thanks @graemerocher for your reply!