exception swallowed, NPE created upon trouble getting JNDI connection

  protected Callable<Connection> createConnectionFactory(final Context context,
                                       final Properties initProps) {
...
    final String jndiName = initProps.getProperty(JNDI_NAME);
    final String url = initProps.getProperty(URL); /* is null */
    final String driver = initProps.getProperty(DRIVER); /* is null */
...
    return factory = new Callable<Connection>() {
      @Override
      public Connection call() throws Exception {
...
        try {
          if(url != null){
            c = DriverManager.getConnection(url, initProps);
          } else if(jndiName != null){
...
/* error occurs */
...
          }
        } catch (SQLException e) {
/* exception handler assumes that try block followed "url != null" path; in the JNDI case, driver is null, and DocBuilder.loadClass(..) throws a NPE */
          Driver d = (Driver) DocBuilder.loadClass(driver, context.getSolrCore()).newInstance();
          c = d.connect(url, initProps);
        }
...
      }
    };
  }