character « validation « Java Regex Q&A

1. regular expression, only contain lower case or uppercase characters or both, for username validation    stackoverflow.com

To validate my string, I need the string only contains lowercase or uppercase or both cases mixed characters from A(a) to Z(z), and string length should be in the range from ...

2. how to use regular expression for validation of String must begin with letter, all other characters can be letter/number/space in java    stackoverflow.com

I am doing validation of String which contains ASAHSHAS,342746726,GHG55656 this valid String and spaces are allowed. Thanks In advance!!

3. Regex validation - show offending character(s). javax.validation    stackoverflow.com

There's regex validation in JSR-303 (javax.validation). For example:

@Pattern(regexp="[\w_\\.]+")
private String username;

4. validation Special character using Regular Expressions    coderanch.com

5. validation Special character using Regular Expressions    forums.oracle.com

6. How to validate UTF-8 characters using Regex?    forums.oracle.com

Actually, I am trying to validate a string, which can contain word characters (A-Za-z0-9), spaces, a few special characters like /, comma(.), Period(.), # and may also contain any of the UTF-8 characters. Though i have been able to formulate a regex for validation of word caharacters and the special characters, i don't know how we can validate for UTF-8 characters ...

7. Validating input if nonalphanumeric character without using regex    forums.oracle.com