static boolean isSystemWindows() {
        return File.separatorChar == '\\';
    }
Check the file path to ensure its valid and prevent directory traversal security issues.

@param filePath the file path to test
@param mustExist true if the directory must exist on disk, false if not
@return the updated file path
primefaces/src/main/java/org/primefaces/util/FileUploadUtils.java