I have two profiles in Spring: `first` and `second`. If I use the `first` profile, I want to create a datasource based on postgres, but if I use `second` I don't want any datasource created at all. I've defined my `JpaEntityConfig` class as:

```
@Configuration
@ConfigurationProperties()
public class JpaEntityConfig {

    @Autowired
    DataSource dataSource;

    public DataSource dataSource() {
        return dataSource;
    }

    ...
}

```

if I set `spring.profiles.active=first` then it works fine, however if I set it to `spring.profiles.active=second` then I'm getting the following error:

```
Field dataSource in com.package.JpaEntityConfig required a bean of type 'javax.sql.DataSource' that could not be found.

The injection point has the following annotations:
    - @org.springframework.beans.factory.annotation.Autowired(required=true)

Action:
Consider defining a bean of type 'javax.sql.DataSource' in your configuration.

```

how can I get around this?