Spring @Configuration and injecting bean dependencies as method parameters

One of the ways Spring recommends injecting inter-dependencies between beans is shown in the following sample copied from the Spring's reference guide here:

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@Configuration public class AppConfig {    @Bean  public Foo foo() {   return new Foo(bar());  }    @Bean  public Bar bar() {   return new Bar("bar1");  }   }

So here, bean `foo` is being injected with a `bar` dependency.

However, there is one alternate way to inject dependency that is not documented well, it is to just take the dependency as a `@Bean` method parameter this way:

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@Configuration public class AppConfig {    @Bean  public Foo foo(Bar bar) {   return new Foo(bar);  }    @Bean  public Bar bar() {   return new Bar("bar1");  }   }

There is a catch here though, the injection is now by type, the `bar` dependency would be resolved by type first and if duplicates are found, then by name:

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@Configuration public static class AppConfig {    @Bean  public Foo foo(Bar bar1) {   return new Foo(bar1);  }    @Bean  public Bar bar1() {   return new Bar("bar1");  }    @Bean  public Bar bar2() {   return new Bar("bar2");  } }

In the above sample dependency `bar1` will be correctly injected. If you want to be more explicit about it, an @Qualifer annotation can be added in:

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@Configuration public class AppConfig {    @Bean  public Foo foo(@Qualifier("bar1") Bar bar1) {   return new Foo(bar1);  }    @Bean  public Bar bar1() {   return new Bar("bar1");  }    @Bean  public Bar bar2() {   return new Bar("bar2");  } }

So now the question of whether this is recommended at all, I would say yes for certain cases. For eg, had the bar bean been defined in a different @Configuration class , the way to inject the dependency then is along these lines:

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@Configuration public class AppConfig {    @Autowired  @Qualifier("bar1")  private Bar bar1;    @Bean  public Foo foo() {   return new Foo(bar1);  }   }

I find the method parameter approach simpler here:

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@Configuration public class AppConfig {    @Bean  public Foo foo(@Qualifier("bar1") Bar bar1) {   return new Foo(bar1);  }   }

Thoughts?