Android里的四大組建類到底是怎么創(chuàng)建的呢溃蔫？是直接new出來的還是？琳猫，通過下面源碼可以看到都是類加載器方式即通過反射的方式生成的（調(diào)用者都是在ActivityThread里）

//9.0源碼
public class AppComponentFactory {

    public @NonNull Application instantiateApplication(@NonNull ClassLoader cl,
            @NonNull String className)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return (Application) cl.loadClass(className).newInstance();
    }


    public @NonNull Activity instantiateActivity(@NonNull ClassLoader cl, @NonNull String className,
            @Nullable Intent intent)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return (Activity) cl.loadClass(className).newInstance();
    }

   
    public @NonNull BroadcastReceiver instantiateReceiver(@NonNull ClassLoader cl,
            @NonNull String className, @Nullable Intent intent)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return (BroadcastReceiver) cl.loadClass(className).newInstance();
    }


    public @NonNull Service instantiateService(@NonNull ClassLoader cl,
            @NonNull String className, @Nullable Intent intent)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return (Service) cl.loadClass(className).newInstance();
    }

   
    public @NonNull ContentProvider instantiateProvider(@NonNull ClassLoader cl,
            @NonNull String className)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return (ContentProvider) cl.loadClass(className).newInstance();
    }

    /**
     * @hide
     */
    public static final AppComponentFactory DEFAULT = new AppComponentFactory();
}