Factory Pattern ~ A Modern Approach - 4 (FileReaderFactory)

FileReaderFactory.java

@Service
public class FileReaderFactory {
    private EnumMap<FileType, FileReader> fileReaders;

    public FileReaderFactory(List<FileReader> fileReaderList){
        fileReaders = new EnumMap<>(FileType.class);
        fileReaderList.forEach(reader -> fileReaders.put(reader.getSupportedFileType(), reader));
    }

    public FileReader getFileReader(String extension){
        return fileReaders.get(FileType.fileTypeOf(extension));
    }
}