用Java中的XPath查询HTML页面

问题描述

任何人都可以给我一个Java库，允许我通过html页面执行XPath查询吗？我尝试使用JAXP，但它一直给我一个奇怪的错误，我似乎无法修复（线程主java.io.IOException：服务器返回的HTTP响应代码： 503 for URL：）。

非常感谢。

编辑

我发现这个：

  //创建一个新的SAX解析器工厂
 SAXParserFactory factory = SAXParserFactory.newInstance（）; 
 
 //打开验证
 factory.setValidating（true）; 
 
 //创建一个验证的SAX解析器实例
 SAXParser parser = factory.newSAXParser（）; 
 
 //创建一个新的DOM Document Builder工厂
 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance（）; 
 
 //打开验证
 factory.setValidating（true）; 
 
 //创建一个验证的DOM解析器
 DocumentBuilder builder = factory.newDocumentBuilder（）; 
  

from 但是，将argumrent变成false并没有改变任何东西。

解决方案

将解析器设置为非验证只会关闭验证;它确实不会禁止获取DTD。获取DTD不仅需要进行验证，还需要扩展实体......据我所知。

如果您想取消DTD的提取，您需要向 DocumentBuilderFactory 或 DocumentBuilder 注册适当的 EntityResolver 。实现 EntityResolver 的 resolveEntity 方法总是返回一个空字符串。

Can anyone advise me a library for Java that allows me to perform an XPath Query over an html page?

I tried using JAXP but it keeps giving me a strange error that I cannot seem to fix (thread "main" java.io.IOException: Server returned HTTP response code: 503 for URL: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd).

Thank you very much.

EDIT

I found this:

// Create a new SAX Parser factory
SAXParserFactory factory = SAXParserFactory.newInstance();

// Turn on validation
factory.setValidating(true);

// Create a validating SAX parser instance
SAXParser parser = factory.newSAXParser();

// Create a new DOM Document Builder factory
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

// Turn on validation
factory.setValidating(true);

// Create a validating DOM parser
DocumentBuilder builder = factory.newDocumentBuilder();

from http://www.ibm.com/developerworks/xml/library/x-jaxpval.html But turning the argumrent to false did not change anything.

解决方案

Setting the parser to "non validating" just turns off validation; it does not inhibit fetching of DTD's. Fetching of DTD is needed not just for validation, but also for entity expansion... as far as I recall.

If you want to suppress fetching of DTD's, you need to register a proper EntityResolver to the DocumentBuilderFactory or DocumentBuilder. Implement the EntityResolver's resolveEntity method to always return an empty string.

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