DataSourceBuilder does not pickup ConfigurationProperties(prefix="...") - spring

Question

My application.properties
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.username=${env.H2_USER}
spring.datasource.password=${env.H2_PASS}
spring.token-datasource.url=jdbc:mysql://${env.MYSQL_HOST}/${env.MYSQL_DB}
spring.token-datasource.username=${env.MYSQL_USER}
spring.token-datasource.password=${env.MYSQL_PASS}
My Configuration.java code snippet
#Configuration
public class DataSourceConfiguration {
#Bean
#Primary
#ConfigurationProperties(prefix = "spring.datasource")
public DataSource regularDataSource() {
DataSource dataSource = DataSourceBuilder.create().build();
return dataSource;
}
#Bean
#ConfigurationProperties(prefix = "spring.token-datasource")
public DataSource tokenDataSource() {
DataSource dataSource = DataSourceBuilder.create().build();
return dataSource;
}
}
However, if I put a break point at each of return dataSource;, I see the DataSource object not populated with the correponding property values, e.g. jdbcUrl would be null.
Any help?
Thanks!

Answer 1

Followed https://docs.spring.io/spring-boot/docs/2.4.2/reference/html/howto.html#howto-two-datasources and crafted following code which works:
#Configuration
public class DataSourceConfiguration {
#Bean
#Primary
#ConfigurationProperties("spring.datasource")
public DataSourceProperties regularDataSourceProperties() {
return new DataSourceProperties();
}
#Bean
#Primary
#ConfigurationProperties("spring.datasource.configuration")
public HikariDataSource regularDataSource() {
HikariDataSource dataSource = regularDataSourceProperties().initializeDataSourceBuilder()
.type(HikariDataSource.class).build();
return dataSource;
}
#Bean
#ConfigurationProperties("spring.token-datasource")
public DataSourceProperties tokenDataSourceProperties() {
return new DataSourceProperties();
}
#Bean
#ConfigurationProperties("spring.token-datasource.configuration")
public DataSource tokenDataSource() {
DataSource dataSource = tokenDataSourceProperties().initializeDataSourceBuilder().build();
return dataSource;
}
}
It's interesting that the original code snippet does NOT work, while it's still the approach recommened by many Java tutorials and stackoverflow posts. For example,
https://www.baeldung.com/spring-data-jpa-multiple-databases
Spring Boot Configure and Use Two DataSources