Define default implementation for injection in Spring?

dependency-injection, java, qualifiers, spring

Solution

You can mark one implementation with `@Primary` which will then be used as default. When using xml you can use the `primary` element inside the `bean` element to set an instance to the primary bean instance to use.

See http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/context/annotation/Primary.html

Problem

I have a base class that is extended by some other classes. Therefore I have to provide qualifiers for being able to inject a specific instance. I wonder if I could mark any of these classes (eg the most upper class) as default class, which would be picked up if no qualifier is provided on `@Autowired`? ``` @Service //@Qualifier("Parent") class ParentRunner; @Service @Qualifier("Child") class ChildRunner extends ParentRunner; ``` The following does at least not work: ``` @Autowired //@Qualifier("Parent") private ParentRunner runner; ```

Original source