Is it possible to use @Resource on a constructor?

Question

I was wondering if it possible to use the @Resource annotation on a constructor.

My use case is that I want to wire a final field called bar.

public class Foo implements FooBar {

    private final Bar bar;

    @javax.annotation.Resource(name="myname")
    public Foo(Bar bar) {
        this.bar = bar;
    }
}

I get a message that the @Resource is not allowed on this location. Is there any other way I could wire the final field?

Answer 1

From the source of @Resource:

@Target({TYPE, FIELD, METHOD})
@Retention(RUNTIME)
public @interface Resource {
    //...
}

This line:

@Target({TYPE, FIELD, METHOD})

means that this annotation can only be placed on Classes, Fields and Methods. CONSTRUCTOR is missing.

Answer 2

To complement Robert Munteanu's answer and for future reference, here is how the use of @Autowired and @Qualifier on constructor looks :

public class FooImpl implements Foo {

    private final Bar bar;

    private final Baz baz;

    @org.springframework.beans.factory.annotation.Autowired
    public Foo(Bar bar, @org.springframework.beans.factory.annotation.Qualifier("thisBazInParticular") Baz baz) {
        this.bar = bar;
        this.baz = baz;
    }
}

In this example, bar is just autowired (i.e. there is only one bean of that class in the context so Spring knows which to use), while baz has a qualifier to tell Spring which particular bean of that class we want injected.