Question

Using Guice, one can do the following:

interface Leg {}

_

class LeftLeg implements Leg {
    public String toString() {
        return "LeftLeg";
    }
}

_

class RightLeg implements Leg {
    public String toString() {
        return "RightLeg";
    }
}

_

class Robot {
    final Leg leftLeg_;
    final Leg rightLeg_;

    @Inject
    Robot(@Named("left") Leg leftLeg, @Named("right") Leg rightLeg) {
        leftLeg_ = leftLeg;
        rightLeg_ = rightLeg;
    }

    public String toString() {
        return "leftLeg_=" + leftLeg_ + ", rightLeg_=" + rightLeg_;
    }
}

_

class RobotTest {
    @Test
    public void t1() throws Exception {
        Injector inj = Guice.createInjector(new AnGuiceModule());
        Robot r = inj.getInstance(Robot.class);
        assertEquals(r.toString(), "leftLeg_=LeftLeg, rightLeg_=RightLeg");
    }
}

_

class AnGuiceModule extends AbstractModule {
    protected void configure() {
        bind(Leg.class).annotatedWith(Names.named("left")).to(LeftLeg.class);
        bind(Leg.class).annotatedWith(Names.named("right")).to(RightLeg.class);
    }
}

How can i achieve the same thing with Spring 3.x (3.1.x or 3.2) using JSR-330 (optional) annotations and JavaConfig without using XML configuration?

Answer 1

The closest i could find is following (The definition of the Robot and Leg* classes does not change):

public class RobotTest {

    @Test
    public void t1() throws Exception {
        ApplicationContext ctx = new 
               AnnotationConfigApplicationContext(RobotConfig.class, Robot.class);
        Robot r = ctx.getBean(Robot.class);
        assertEquals("leftLeg_=LeftLeg, rightLeg_=RightLeg", r.toString());
    }
}

@Configuration
class RobotConfig {

    @Bean
    public Leg leftLeg() {
        return new LeftLeg();
    }

    @Bean
    public Leg rightLeg() {
        return new RightLeg();
    }

}

Alternative would be:

public class RobotTest {

    @Test public void t1() throws Exception {
        ApplicationContext ctx = new 
               AnnotationConfigApplicationContext(RobotConfig.class);
        Robot r = ctx.getBean(Robot.class);
        assertEquals("leftLeg_=LeftLeg, rightLeg_=RightLeg", r.toString());
    }
}

@Configuration
class RobotConfig {

   @Bean @Scope("prototype") public Robot robot() {
       return new Robot(leftLeg(), rightLeg());
   }

    @Bean @Scope("prototype") public Leg leftLeg() {
        return new LeftLeg();
    }

    @Bean @Scope("prototype") public Leg rightLeg() {
        return new RightLeg();
    }
}