Dfyjkt

I have a situation where I'm using one possible implementation for a particular bean, and it looks like this:

@Configuration
public class MyConfig 

 @Autowired
 private ApplicationContext context;

 @Bean
 public SomeInterface someInterface() 
 if (this.context.getEnvironment().getProperty("implementation") != null) 
 return new ImplementationOne();
 else 
 return new ImplementationTwo();
 
 

This worked great so far, until a new requirement came in, to use an additional interface which for the moment only ImplementationTwo provides implementation, and it wouldn't make sense to use it with ImplementationOne:

 @Bean
 public SomeOtherInterface someOtherInterface() 
 return new ImplementationTwo();
 

I guess this would work, but I'm wondering if this really make sense because in one scenario I could have both beans basically instantiating the same object. Does that make sense ? Is there maybe a better way to achieve the same thing?

I believe, if you have multiple implementations of a single interface, then you should go about specific bean names as below.

Here implementation1 will be the primary bean created and injected where ever we have the Interface1 dependency.

@Primary
@Bean
public Interface1 implementation1() 
 return new Implementation2();


@Bean
public Interface1 implementation2() 
 return new Implementation2();

If we need implementation2 injected we need @Resource annotation as below.

@Resource(name="implementation2")
Interface1 implementation2;