Java Selenium Webdriver：处理 NoSuchElementException 的最佳实践
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Selenium Webdriver: best practice to handle a NoSuchElementException
提问by Steerpike
After much searching and reading, I'm still unclear as to the best way to handle a failed assertion using Webdriver. I would have thought this was a common and core piece of functionality. All I want to do is:
经过大量搜索和阅读，我仍然不清楚使用 Webdriver 处理失败断言的最佳方法。我会认为这是一个常见的核心功能。我想做的就是：
- look for an element
- if present - tell me
- if not present - tell me
- 寻找一个元素
- 如果存在 - 告诉我
- 如果不存在 - 告诉我
I want to present the results for a non technical audience, so having it throw 'NoSuchElementExceptions' with a full stack trace is not helpful. I simply want a nice message.
我想向非技术受众展示结果，因此让它抛出带有完整堆栈跟踪的“NoSuchElementExceptions”并没有帮助。我只是想要一个好消息。
My test:
我的测试：
@Test
public void isMyElementPresent(){
// WebElement myElement driver.findElement(By.cssSelector("#myElement"));
if(driver.findElement(By.cssSelector("#myElement"))!=null){
System.out.println("My element was found on the page");
}else{
System.out.println("My Element was not found on the page");
}
}
I still get a NoSuchElementException thrown when I force a fail. Do I need a try/catch as well? Can I incorporate Junit assertions and/or Hamcrest to generate a more meaningful message without the need for a System.out.println?
当我强制失败时，我仍然会抛出 NoSuchElementException。我也需要尝试/捕获吗？我可以在不需要 System.out.println 的情况下合并 Junit 断言和/或 Hamcrest 来生成更有意义的消息吗？
采纳答案by Vish
I have encountered similar situations. According to the Javadocfor the findElementand findElementsAPIs, it appears that the findElementbehavior is by design. You should use findElementsto check for non-present elements.
我也遇到过类似的情况。按照的Javadoc的findElement和findElementsAPI的，看来该findElement行为是由设计。您应该使用findElements来检查不存在的元素。
Since in your case, there's a chance that the WebElement is not present, you should use findElementsinstead.
由于在您的情况下，有可能 WebElement 不存在，您应该findElements改用。
I'd use this as follows.
我会按如下方式使用它。
List<WebElement> elems = driver.findElements(By.cssSelector("#myElement"));
if (elems.size == 0) {
System.out.println("My element was not found on the page");
} else
System.out.println("My element was found on the page");
}
回答by xyz
you can do something to check if element exists
你可以做一些事情来检查元素是否存在
public boolean isElementExists(By by) {
boolean isExists = true;
try {
driver.findElement(by);
} catch (NoSuchElementException e) {
isExists = false;
}
return isExists;
}
回答by Nic
What about using an xPath inside of a try-catch, passing the elementype, attribute and text as follows?
如何在 try-catch 中使用 xPath，按如下方式传递元素类型、属性和文本？
try {
driver.FindElement(
By.XPath(string.Format("//{0}[contains(@{1}, '{2}')]",
strElemType, strAttribute, strText)));
return true;
}
catch (Exception) {
return false;
}
