Java 如何使用自定义限定符注释动态获取bean

我们使用自定义限定符注释来创建和注入bean。我们如何在运行时通过指定自定义限定符来动态选择bean

自定义限定符：

@Target({ ElementType.FIELD, ElementType.METHOD, ElementType.TYPE,
        ElementType.PARAMETER })
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface PlatformQualifiers {

    public static enum OperatingSystems {
        IOS, ANDROID
    }

    OperatingSystems operatingSystem() default OperatingSystems.IOS;

    public enum DeviceTypes {
        Mobile, Tablet, ANY, Other
    }

    DeviceTypes[] deviceType() default { DeviceTypes.ANY };
}

Bean接口：

@FunctionalInterface
public interface Platform {

    String getDeviceDetails();
}

Bean配置：

@Configuration
public class PlatformConfig {

    @Bean
    @PlatformQualifiers(operatingSystem = OperatingSystems.IOS, deviceType = DeviceTypes.Mobile)
    public Platform getIphone6() {
        return () -> "iphone6";
    }

    @Bean
    @PlatformQualifiers(operatingSystem = OperatingSystems.IOS, deviceType = DeviceTypes.Tablet)
    public Platform getIpad() {
        return () -> "ipad3";

    }

    @Bean
    @PlatformQualifiers(operatingSystem = OperatingSystems.ANDROID, deviceType = DeviceTypes.Mobile)
    public Platform getAndroidPhone() {
        return () -> "AndroidPhoneSamsung";
    }

}

当前应用程序代码：

@Configuration
@ComponentScan
public class MainApplication {

    @Autowired
    @PlatformQualifiers(operatingSystem = OperatingSystems.IOS, deviceType = DeviceTypes.Mobile)
    Platform iphone;


    @Autowired
    @PlatformQualifiers(operatingSystem = OperatingSystems.ANDROID, deviceType = DeviceTypes.Mobile)
    Platform androidPhone;

    public  void getDevice(String osType, String deviceType ) {
        if(osType == "ios" && deviceType == "mobile") {
            System.out.println(iphone.getDeviceDetails());
        }

        if(osType == "android" && deviceType == "mobile") {
            System.out.println(androidPhone.getDeviceDetails());
        }

    }

    public static void main(String[] args) {
        ApplicationContext context = new AnnotationConfigApplicationContext(MainApplication.class);
        MainApplication mainApplication = context.getBean(MainApplication.class);
        mainApplication.getDevice("ios" ,"mobile");
        mainApplication.getDevice("android" , "mobile");


    }

}

我正在寻找一种解决方案，比如在运行时我可以在何处使用限定符访问bean，如下所示：

@Configuration
@ComponentScan
public class MainApplication2 {
    @Autowired
    ApplicationContext context;

    public  void getDevice(DeviceTypes deviceType, OperatingSystems osType ) {
           >>>>>>>>>>> Looking of something of type following : 
            Platform p =    context.getBean(some input consisting to identify bean by  deviceType and osType)


            System.out.println(p.getDeviceDetails());
        }

    public static void main(String[] args) {
        ApplicationContext context = new AnnotationConfigApplicationContext(MainApplication2.class);
        MainApplication2 application = context.getBean(MainApplication2.class);
        application.getDevice(DeviceTypes.Mobile, OperatingSystems.ANDROID);
    }
}

---

在这种情况下，如何基于设备类型和操作系统在运行时从applicationContext获取bean

其中一种方法是创建

平台

bean的

映射

，并将其注入调用

getDevice

的bean中。映射的键可以是设备类型

---

同样的另一种方法是让你的bean实现

initializebean

和

ApplicationContextAware

，并在afterPropertiesSet

中使用'getBeansWithAnnotation'与

FindNotationOnBean'结合使用，以动态地填充映射或查找bean。

四年后仍然没有接近CDI优雅的解决方案。。。难以置信的