CODEWITHSUNDEEP
javaspringdependency-injection
O.m
O.m

Reputation: 75

Spring's @Autowired constructor gets overriden/ignored

I have SomeStartegy interface with two implementations:

@Primary
@Component
public class OneStrategy implements SomeStrategy {...}
@Component
public class SecondStrategy implements SomeStrategy {...}

I need one of them to be used as a default (primary) implementation and the other to override the default in some cases.

So I wrote something like this:

public class SuperClass {
     @Autowired
     SomeStrategy strategy;
}

 

public class SubClass extends SuperClass {
     @Autowired
     public SubClass(SecondStrategy secondStrategy) {
         this.strategy = secondStrategy;
     }
}

Injecting SubClass, I can see in debug that it's ctor is called and the assignment is done like I would expect. However, somehow it ends up with an instance of OneStrategy instead.
What am I missing here? or am I doing this all wrong?

Upvotes: 1

Views: 614

Answers (1)

JB Nizet
JB Nizet

Reputation: 691635

Field injection is made after constructor injection.

Use constructor injection for the superclass too, and call super(secondStrategy) from the subclass constructor.

Upvotes: 1

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