How to validate if a string would be a valid java variable?

Question

How can I best check if a string input would be a valid java variable for coding? I\'m sure I\'m not the first one who is willing to do this. But maybe I\'m missing the righ

Answer 1

Just use the built-in isName method:

public static boolean isName(CharSequence name)

This returns whether or not a name is a syntactically valid qualified name in the latest source version.

See the isName() documentation.

Answer 2

public static boolean isValidJavaIdentifier(String s) {
    if (s.isEmpty()) {
        return false;
    }
    if (!Character.isJavaIdentifierStart(s.charAt(0))) {
        return false;
    }
    for (int i = 1; i < s.length(); i++) {
        if (!Character.isJavaIdentifierPart(s.charAt(i))) {
            return false;
        }
    }
    return true;
}

EDIT: and, as @Joey indicates, you should also filter out keywords and reserved words.