[FIXED] Spring choose bean implementation at runtime

Issue

I'm using Spring Beans with annotations and I need to choose different implementation at runtime.

@Service
public class MyService {
   public void test(){...}
}

For example for windows's platform I need MyServiceWin extending MyService, for linux platform I need MyServiceLnx extending MyService.

For now I know only one horrible solution:

@Service
public class MyService {

    private MyService impl;

   @PostInit
   public void init(){
        if(windows) impl=new MyServiceWin();
        else impl=new MyServiceLnx();
   }

   public void test(){
        impl.test();
   }
}

Please consider that I'm using annotation only and not XML config.

Solution

You can move the bean injection into the configuration, as:

@Configuration
public class AppConfig {

    @Bean
    public MyService getMyService() {
        if(windows) return new MyServiceWin();
        else return new MyServiceLnx();
    }
}

Alternatively, you may use profiles windows and linux, then annotate your service implementations with the @Profile annotation, like @Profile("linux") or @Profile("windows"), and provide one of this profiles for your application.

Answered By - Stanislav