Spring choose bean implementation at runtime

Question

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.

Answer 1

1. Implement a custom Condition

public class LinuxCondition implements Condition {   @Override   public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {     return context.getEnvironment().getProperty("os.name").contains("Linux");  } } 

Same for Windows.

2. Use @Conditional in your Configuration class

@Configuration public class MyConfiguration {    @Bean    @Conditional(LinuxCondition.class)    public MyService getMyLinuxService() {       return new LinuxService();    }     @Bean    @Conditional(WindowsCondition.class)    public MyService getMyWindowsService() {       return new WindowsService();    } } 

3. Use @Autowired as usual

@Service public class SomeOtherServiceUsingMyService {      @Autowired         private MyService impl;      // ...  }