The following method is for setting the transfer type of an FTP connection. Basically, I'd like to validate the character input (see comments).
Is this going overboard? Is there a more elegant approach? How do you approach parameter validation in general? Any comments are welcome.
public void setTransferType(Character typeCharacter,
Character optionalSecondCharacter) throws NumberFormatException,
IOException {
// http://www.nsftools.com/tips/RawFTP.htm#TYPE
// Syntax: TYPE type-character [second-type-character]
//
// Sets the type of file to be transferred. type-character can be any
// of:
//
// * A - ASCII text
// * E - EBCDIC text
// * I - image (binary data)
// * L - local format
//
// For A and E, the second-type-character specifies how the text should
// be interpreted. It can be:
//
// * N - Non-print (not destined for printing). This is the default if
// second-type-character is omitted.
// * T - Telnet format control (<CR>, <FF>, etc.)
// * C - ASA Carriage Control
//
// For L, the second-type-character specifies the number of bits per
// byte on the local system, and may not be omitted.
final Set<Character> acceptedTypeCharacters = new HashSet<Character>(Arrays.asList(
new Character[] {'A','E','I','L'}
));
final Set<Character> acceptedOptionalSecondCharacters = new HashSet<Character>(Arrays.asList(
new Character[] {'N','T','C'}
));
if( acceptedTypeCharacters.contains(typeCharacter) ) {
if( new Character('A').equals( typeCharacter ) || new Character('E').equals( typeCharacter ) ){
if( acceptedOptionalSecondCharacters.contains(optionalSecondCharacter) ) {
executeCommand("TYPE " + typeCharacter + " " + optionalSecondCharacter );
}
} else {
executeCommand("TYPE " + typeCharacter );
}
}
}
