Xpath语法和与html的结合使用

向右看齐 2022-06-03 00:38 379阅读 0赞

# 1.xpath(XML PATH LANUAGE)语法 #

上下文：引用池或者引用区。 ![20171213114600319][]

###       .的作用: ###

即使我们对取出来的子节点进行操作，默认还是对根节点进行的操作.使用点可以将根切换到目前的引用对象.

# 2.xpath与html的结合使用 #

1.导入相关依赖：

<dependency>  
    <groupId>jaxen</groupId>  
    <artifactId>jaxen</artifactId>  
    <version>1.1.1</version>  
</dependency>  
  
<dependency>  
        <groupId>net.sourceforge.htmlcleaner</groupId>  
        <artifactId>htmlcleaner</artifactId>  
        <version>2.9</version>  
    </dependency>

2.通过xpath对文档进行操作

import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileNotFoundException;  
import java.io.IOException;  
import org.htmlcleaner.CleanerProperties;  
import org.htmlcleaner.DomSerializer;  
import org.htmlcleaner.HtmlCleaner;  
import org.htmlcleaner.TagNode;  
import org.w3c.dom.Document;  
import org.w3c.dom.Node;  
import javax.xml.parsers.ParserConfigurationException;  
import javax.xml.xpath.XPath;  
import javax.xml.xpath.XPathConstants;  
import javax.xml.xpath.XPathExpression;  
import javax.xml.xpath.XPathExpressionException;  
import javax.xml.xpath.XPathFactory;  
  
  
import org.w3c.dom.NodeList;  
import org.xml.sax.SAXException;  
  
  
  
  
public class TestReg \{  
  
  
public static void XpathUtil(String path)  
throws XPathExpressionException, SAXException, IOException, ParserConfigurationException \{  
//生成xpathfactory和xpath对象  
XPathFactory xpathfactory = XPathFactory.newInstance();  
XPath xpath = xpathfactory.newXPath();  
  
  
//对文档流进行加工  
HtmlCleaner hc = new HtmlCleaner();  
TagNode tn;  
try \{  
tn = hc.clean(getInputStream(path));  
\} catch (FileNotFoundException e1) \{  
// TODO Auto-generated catch block  
e1.printStackTrace();  
\} catch (IOException e1) \{  
// TODO Auto-generated catch block  
e1.printStackTrace();  
\}  
Document dom = new DomSerializer(new CleanerProperties()).createDOM(tn);  
  
  
//通过xpath对dom进行操作  
XPathExpression express = xpath.compile("/\*");  
Object str = express.evaluate(dom, XPathConstants.NODESET);  
NodeList nodelist = (NodeList) str;  
for (int i = 0; i < nodelist.getLength(); i++) \{  
Node temp = nodelist.item(i);  
temp.removeChild(temp.getChildNodes().item(0));  
\}  
\}  
  
  
  
// 获取输入流  
public static String getInputStream(String filepath) throws IOException, FileNotFoundException \{  
FileInputStream fis = new FileInputStream(new File(filepath));  
StringBuffer value = new StringBuffer();  
int len = -1;  
byte\[\] tmp = new byte\[1024\];  
while ((len = fis.read(tmp)) != -1) \{  
value.append(new String(tmp, 0, len, "utf-8"));  
\}  
return value.toString();  
\}  
  
  
\}

[20171213114600319]: /images/20220603/707c25bf1fc6452da5f6bbeb88421239.png