CustomCacheManager

custom_cache_manager.dart

import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as p;

class CustomCacheManager extends BaseCacheManager {
  static const key = 'custom_cache_manager';

  static CustomCacheManager _instance;

  factory CustomCacheManager() {
    if (_instance == null) {
      _instance = CustomCacheManager._();
    }
    return _instance;
  }

  CustomCacheManager._()
      : super(
          key,
          fileService: CustomHttpFileService(),
        );

  Future<String> getFilePath() async {
    var directory = await getApplicationSupportDirectory();
    return p.join(directory.path, key);
  }
}

class CustomHttpFileService extends HttpFileService {
  CustomHttpFileService() : super();

  @override
  Future<FileServiceResponse> get(String url,
      {Map<String, String> headers = const {}}) {
    if (url.startsWith('https')) {
      url = url.replaceFirst('https', 'http');
    }
    return super.get(url, headers: headers);
  }
}

my_component.dart

class MyComponent extends StatelessWidget {
  final String url;

  const MyComponent({Key key, this.url}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return CachedNetworkImage(
      imageUrl: url,
      cacheManager: CustomCacheManager(),
    );
  }
}