I want to check that Java String or character array is not just made up of whitespaces, using Java?
How can I check if string contains characters & whitespace, not just whitespace?
EDIT: I removed the bit about alphanumeric characters, so it makes more sense.
Shortest solution I can think of:
if (string.trim().length() > 0) ...
This only checks for (non) white space. If you want to check for particular character classes, you need to use the mighty
match() with a regexp such as:
if (string.matches(".*\\w.*")) ...
...which checks for at least one (ASCII) alphanumeric character.