android_java注解

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD})
public @interface ViewId {
    int value();
}



public class Injector {

    public static void inject(Object object) {
        try {
            if (object instanceof Activity) {
                injectView(object, ((Activity) object).getWindow().getDecorView());
            }
            if (object instanceof Dialog) {
                injectView(object, ((Dialog) object).getWindow().getDecorView());
            }
            if (object instanceof PopupWindow) {
                injectView(object, ((PopupWindow) object).getContentView());
            }
        } catch (Exception e) {
            throw new NullPointerException(e.toString());
        }
    }

    public static void inject(Object object, View view) {
        try {
            injectView(object, view);
        } catch (Exception e) {
            throw new NullPointerException(e.toString());
        }

    }

    private static void injectView(Object paramObject, View viewById) throws Exception {
        for (Field field : getFields(paramObject.getClass())) {
            ViewId viewId = field.getAnnotation(ViewId.class);
            if (viewId != null) {
                View view = viewById.findViewById(viewId.value());
                if (view != null) {
                    field.setAccessible(true);
                    field.set(paramObject, view);
                }
            }
        }
    }

    private static List<Field> getFields(Class<?> paramClass) {
        ArrayList<Field> localArrayList = new ArrayList<>();
        Field[] arrayOfField = paramClass.getDeclaredFields();
        localArrayList.addAll(Arrays.asList(arrayOfField).subList(0, arrayOfField.length));
        if ((paramClass != Object.class) && (paramClass.getSuperclass() != null)) {
            localArrayList.addAll(getFields(paramClass.getSuperclass()));
        }
        return localArrayList;
    }
}