public static String copyDirective(HashMap<String,String> src,HashMap<String,String> dst,String directive){
  String directiveValue=src.get(directive);
  if (directiveValue != null) {
    dst.put(directive,directiveValue);
  }
  return directiveValue;
}

public static String copyDirective ( HashMap < String , String > src , HashMap < String , String > dst , String directive ) { String directiveValue = src . get ( directive ) ; if ( directiveValue != null ) { dst . put ( directive , directiveValue ) ; } return directiveValue ; }
copy the directive from the source map to the destination map , if it ' s value isn ' t null . ( a directive is a parameter of the digest authentication process . )
