question: @ Override public String generateURL ( CategoryDataset dataset , int series , int category ) { String url = this . prefix ; Comparable seriesKey = dataset . getRowKey ( series ) ; Comparable categoryKey = dataset . getColumnKey ( category ) ; boolean firstParameter = ! url . contains ( "?" ) ; url += firstParameter ? "?" : "&amp;" ; try { url += this . seriesParameterName + "=" + URLEncoder . encode ( seriesKey . toString ( ) , "UTF-8" ) ; url += "&amp;" + this . categoryParameterName + "=" + URLEncoder . encode ( categoryKey . toString ( ) , "UTF-8" ) ; } catch ( UnsupportedEncodingException ex ) { throw new RuntimeException ( ex ) ; } return url ; }
target:  Generates a URL for a particular item within a series.