code: public void setQuery( String query )
      {
          _parameters = null;
  
          if ( query == null || query.length() == 0 ) { return; }
  
          for ( StringTokenizer tok = new StringTokenizer( query, "&" ); tok.hasMoreElements(); )
          {
              String queryItem = tok.nextToken();
  
              if ( queryItem.startsWith( "amp;" ) )
              {
                  queryItem = queryItem.substring( 4 );
              }
  
              int eq = queryItem.indexOf( '=' );
              if ( eq != -1 )
              {
                  addParameter( queryItem.substring( 0, eq ) , queryItem.substring( eq + 1 ), true );
              }
              else
              {
                  addParameter( queryItem, null, true );
              }
          }
      }
docs: Sets (and resets) the query string.
  This method assumes that the query is already encoded and escaped.
  
  @param query Query string