In Java, I\'ve a File-Name-String. There I want to replace all illegal Characters with \'_\', but not a-z, 0-9, -,. and <
a-z
0-9
-
.
If you want to use more than like [A-Za-z0-9], then check MS Naming Conventions, and dont forget to filter out "...Characters whose integer representations are in the range from 1 through 31,...".