Replacing illegal character in fileName

Question

In Java, I\'ve a File-Name-String. There I want to replace all illegal Characters with \'_\', but not a-z, 0-9, -,. and <

Answer 1

Even simpler

myString = myString.replaceAll("[^\\w.-]", "_");

Predefined Character Classes:

• \w A word character: [a-zA-Z_0-9]