private static String queryString ( final Map < String , List < String > > params ) { final StringBuilder builder = new StringBuilder ( ) ; if ( params != null && params . size ( ) > 0 ) { for ( final Iterator < String > it = params . keySet ( ) . iterator ( ) ; it . hasNext ( ) ; ) { final String key = it . next ( ) ; final List < String > values = params . get ( key ) ; for ( final String value : values ) { try { builder . append ( key + "=" + URLEncoder . encode ( value , "UTF-8" ) + "&" ) ; } catch ( final UnsupportedEncodingException e ) { builder . append ( key + "=" + value + "&" ) ; } } } return builder . length ( ) > 0 ? "?" + builder . substring ( 0 , builder . length ( ) - 1 ) : "" ; } return "" ; }
Encode URL parameters as a query string .