public RegexFileFilter(String pattern,int flags){
  if (pattern == null) {
    throw new IllegalArgumentException("Pattern is missing");
  }
  this.pattern=Pattern.compile(pattern,flags);
}

public RegexFileFilter ( String pattern , int flags ) { if ( pattern == null ) { throw new IllegalArgumentException ( "Pattern is missing" ) ; } this . pattern = Pattern . compile ( pattern , flags ) ; }
construct a new regular expression filter with the specified flags .
