Java Selenium获取视频进度

百度后尝试使用`js.executeScript("$('#VideoID').currentTime;")`报错：org.openqa.selenium.JavascriptException: javascript error: $ is not defined
又百度后改成：`js.executeScript("document.getElementById('VideoID').currentTime;")`报null
尝试`driver.findElement(By.id("VideoID")).getAttribute("currentTime"))`成功