URLUtilCompat

public static @Nullable String getFilenameFromContentDisposition(@NonNull String contentDisposition)

Extract filename from a Content-Disposition header value.

This method implements the parsing defined in RFC 6266, supporting both the filename and filename* disposition parameters. If the passed header value has the "inline" disposition type, this method will return null to indicate that a download was not intended.

If both filename* and filename is present, the former will be returned, as per the RFC. Invalid encoded values will be ignored.

public static @NonNull String guessFileName(
    @NonNull String url,
    @Nullable String contentDisposition,
    @Nullable String mimeType
)

Guesses canonical filename that a download would have, using the URL and contentDisposition.

This method differs from guessFileName in the following ways:

• This method uses an updated parsing of contentDisposition, making this available on older Android versions. See getFilenameFromContentDisposition.
• If the filename guessed from url or contentDisposition already contains an extension, but this extension differs from the one expected from the mimeType, then this method will append the expected extension instead of replacing the one already present. This is done to preserve filenames that contain a "." as part of a filename but where the last part is not meant as an extension.
• If the filename guessed from contentDisposition contains a "/" character, it will be replaced with "_", unlike guessFileName which will only return the part after the last "/" character.

This method will use getFilenameFromContentDisposition to parse the passed contentDisposition.

• If not file extension is present in the guessed file name, one will be added based on the mimetype (this will be ".bin" if mimeType is null).
• If the guessed file name already contains an extension, but this extension doesn't match a provided mimeType, then a new file extension will be added that matches the mimeType.