Question

我想存储此网页的评论部分： -

http://timesofindia.indiatimes.com/india/Officer-who-tracked-major-scams-back-in-Enforcement-Directorate/articleshow/27933692.cms

这是我的java代码： -

import java.io.*;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class UrlReadPageDemo1 {

    public static void main(String[] args) throws XPathExpressionException, IOException {
        System.out.println("helllo\n\n\n");
        Document doc = Jsoup.connect("http://timesofindia.indiatimes.com/india/Officer-who-tracked-major-scams-back-in-Enforcement-Directorate/articleshow/27933692.cms").get();
        String exp = "//div[@class='master_container']/[@id='netspidersosh']/div[@class='navlft']/div[@class='padlftrgt']/div[@class='clearFix']/div[@class='flL left_bdr']/[@id='populatecomment']/[@id='cmtMainBox']/div/[@id='cmtBox']/div/[@id='box']/[@id='cmt']/div/span";

        System.out.println(exp);

        XPathFactory factory = XPathFactory.newInstance();
        XPath xPath = factory.newXPath();
        NodeList fav = (NodeList) xPath.evaluate(exp,doc.getAllElements(), XPathConstants.NODESET);

        Element Comment = (Element) fav.item(17);
        String str = Comment.getTextContent();
        System.out.println(str);
    }
}

发生错误： -

Exception in thread "main" javax.xml.transform.TransformerException: A location step was expected following the '/' or '//' token.
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.error(XPathParser.java:612)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.RelativeLocationPath(XPathParser.java:1641)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.LocationPath(XPathParser.java:1599)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.PathExpr(XPathParser.java:1319)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.UnionExpr(XPathParser.java:1238)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.UnaryExpr(XPathParser.java:1144)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.MultiplicativeExpr(XPathParser.java:1065)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.AdditiveExpr(XPathParser.java:1007)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.RelationalExpr(XPathParser.java:932)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.EqualityExpr(XPathParser.java:872)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.AndExpr(XPathParser.java:836)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.OrExpr(XPathParser.java:809)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.Expr(XPathParser.java:792)
    at com.sun.org.apache.xpath.internal.compiler.XPathParser.initXPath(XPathParser.java:131)
    at com.sun.org.apache.xpath.internal.XPath.<init>(XPath.java:180)
    at com.sun.org.apache.xpath.internal.XPath.<init>(XPath.java:268)
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.eval(XPathImpl.java:188)
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:270)
    at UrlReadPageDemo1.main(UrlReadPageDemo1.java:29)

---------------链接到------------------

javax.xml.xpath.XPathExpressionException
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:284)
    at UrlReadPageDemo1.main(UrlReadPageDemo1.java:29)

所以请帮我解决这个问题...

Answer 1

错误说：

A location step was expected following the '/' or '//' token.

问题是斜线后，括号不够。预计会element或@attribute，可能带有some_axis::前缀。括号中的谓词进一步过滤匹配节点集。要匹配任何元素，请使用*，例如

//div[@class='master_container']/*[@id='netspidersosh']

顺便问一下，为什么这么长的XPath？在HTML中，id值应该是唯一的，因此这个表达式可能就足够了：

//*[@id='cmt']/div/span

更新

可以在以下位置找到XPath的入门级教程：http://zvon.org/xxl/XPathTutorial/Output/example1.html

Xpath中发生错误

1 个答案: