xpath表达式在html文件中查找元素的所有occerence [英] xpath expression to find all occerence of a element in html file

问题描述

我有一个html文件，我需要找到< object> 标签的出现次数。在Java中，我使用XPathExpression //：object [contains（@type，video /）或contains（@type，audio /）] 来查找< object> 标签的出现。它正在检测< object> 标记，但我希望我的文件中存在对象标记的数量。

I have an html file where I need to find the number of occurrences of the <object> tag. In Java I'm using the XPathExpression //:object[contains(@type,"video/") or contains(@type,"audio/")] to find the occurences of the <object> tag. It's detecting the <object> tag but I want the count of number of object tags present in my file.

result = (Boolean) expression.evaluate(inputSource, XPathConstants.BOOLEAN);

其中inputSource包含我的html文件。它返回一个布尔值，当我尝试同样的事情与
xpathValue =（Double）expression.evaluate（inputSource，XPathConstants.NUMBER）; 获取结果为NaN。

where inputSource contains my html file. It is returning a boolean value, when I tried the same thing with xpathValue = (Double) expression.evaluate(inputSource, XPathConstants.NUMBER); getting result as NaN.

解决方案是什么？

推荐答案

我的Java和Xpath有点模糊，但是如果您评估

I'm a bit fuzzy on my Java and Xpath, but if you evaluate

expression.evaluate（inputSource，XPathConstants.NODELIST）

您应该找回与您的查询匹配的所有节点的NodeList，并且您可以获取该列表的长度。

You should get back a NodeList of all the Nodes matching your query, and you can just get the length of that list.

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