code: private String getUrl(DataSource dataSource) {
          Connection conn = null;
          try {
              conn = dataSource.getConnection();
              return conn.getMetaData().getURL();
          } catch (SQLException e) {
              throw new PageException(e);
          } finally {
              if (conn != null) {
                  try {
                      if (closeConn) {
                          conn.close();
                      }
                  } catch (SQLException e) {
                      //ignore
                  }
              }
          }
      }
docs: 获取url
  
  @param dataSource
  @return