Micronaut 限制注射类型

@Singleton
public class V8Engine implements Engine {  // (3)
    @Override
    public String start() {
        return "Starting V8";
    }

    @Override
    public int getCylinders() {
        return 8;
    }

}

@Singleton
class V8Engine implements Engine { // (3)
    int cylinders = 8

    @Override
    String start() {
        "Starting V8"
    }
}

@Singleton
class V8Engine : Engine {

    override var cylinders: Int = 8

    override fun start(): String {
        return "Starting V8"
    }

}

@Singleton
@Bean(typed = Engine.class) // (1)
public class V8Engine implements Engine {  // (2)
    @Override
    public String start() {
        return "Starting V8";
    }

    @Override
    public int getCylinders() {
        return 8;
    }
}

@Singleton
@Bean(typed = Engine) // (1)
class V8Engine implements Engine {  // (2)
    @Override
    String start() { "Starting V8" }

    @Override
    int getCylinders() { 8 }
}

@Singleton
@Bean(typed = [Engine::class]) // (1)
class V8Engine : Engine { // (2)
    override fun start(): String {
        return "Starting V8"
    }

    override val cylinders: Int = 8
}

@MicronautTest
public class EngineSpec {
    @Inject
    BeanContext beanContext;

    @Test
    public void testEngine() {
        assertThrows(NoSuchBeanException.class, () ->
                beanContext.getBean(V8Engine.class) // (1)
        );
        final Engine engine = beanContext.getBean(Engine.class); // (2)
        assertTrue(engine instanceof V8Engine);
    }
}

class EngineSpec extends Specification {
    @Shared @AutoCleanup
    ApplicationContext beanContext = ApplicationContext.run()

    void 'test engine'() {
        when:'the class is looked up'
        beanContext.getBean(V8Engine) // (1)

        then:'a no such bean exception is thrown'
        thrown(NoSuchBeanException)

        and:'it is possible to lookup by the typed interface'
        beanContext.getBean(Engine) instanceof V8Engine // (2)
    }
}

@MicronautTest
class EngineSpec {
    @Inject
    lateinit var beanContext: BeanContext

    @Test
    fun testEngine() {
        assertThrows(NoSuchBeanException::class.java) {
            beanContext.getBean(V8Engine::class.java) // (1)
        }

        val engine = beanContext.getBean(Engine::class.java) // (2)
        assertTrue(engine is V8Engine)
    }
}