@SpringBootApplication
@EnableConfigurationProperties
@ComponentScan

public class MyApplication {
@Bean(name="dmDs")
@ConfigurationProperties("spring.datasource")
public  DataSource dmDataSource(){
    return DataSourceBuilder.create().build();
}
@Bean
public String aBean(){
    DataSource ds = dmDataSource(); // creates a datasource with URL, username and password empty.
    return new String("");
}

spring:
    profiles: test
    datasource:
          url: jdbc:oracle:thin:SOME_URL
          driver-class-name: oracle.jdbc.OracleDriver
          password: test
          username: test

[main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'spring.datasource.url' in [applicationConfig: [classpath:/application.yml]] with type [String]
[main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'spring.datasource.driver-class-name' in [applicationConfig: [classpath:/application.yml]] with type [String]
[main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'spring.datasource.password' in [applicationConfig: [classpath:/application.yml]] with type [String]
[main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'spring.datasource.username' in [applicationConfig: [classpath:/application.yml]] with type [String]