Question

我有一个文本文档，其中每一行都是整个美国专利XML文档。我试图解析它以删除某些功能，如专利号等。我之前没有使用XPath，所以我借用了一些我从Ravi Thapliyal找到的代码在Parse XML Simple String using Java XPath。但是，显然最初的！DOCTYPE标签导致DocumentBuilder试图在某处找到实际文档？

这是我第一次尝试代码：

//convert entire file to ArrayList of strings
        ArrayList<String> doc = new ArrayList<>();
        while(input.hasNext()){
            doc.add(input.nextLine().trim());
        }

int index = 0;
    while(index < doc.size()){
        String xml = doc.get(index);
        XPathFactory xpathFactory = XPathFactory.newInstance();
        XPath xPath = xpathFactory.newXPath();
        InputSource source = new InputSource(new StringReader(xml));

        db.setEntityResolver(new EntityResolver() {
            public InputSource resolveEntity(String publicId, String systemId)
             throws SAXException, java.io.IOException {
                if (systemId.contains("us-patent-grant-v40-2004-12-02.dtd")) {
            return new InputSource(new StringReader(""));
        } else {
            return null;
        }
            }
        });

        String orgName = "";
        try {
            orgName = (String) xPath.evaluate("/agents/adressbook/orgname", source,XPathConstants.STRING);
        } catch (Exception e) {
            e.printStackTrace();
        }

        System.out.println("Document #" + index + " Company: " + orgName);
    }//end while loop that goes through each line (patent document) in file

输入文件中每行的开头在DOCTYPE声明后包含以下内容： us-patent-grant SYSTEM“us-patent-grant-v40-2004-12-02.dtd”[]＆gt;

导致问题的行（91）是：

orgName = (String) xPath.evaluate("/agents/adressbook/orgname", 
       source,XPathConstants.STRING);

堆栈跟踪是：

java.io.FileNotFoundException: C:\Users\Dave\Documents\NetBeansProjects\ParseXML\us-patent-grant-v40-2004-12-02.dtd (The system cannot find the file specified)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:131)
    at java.io.FileInputStream.<init>(FileInputStream.java:87)
    at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
    at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:616)
Document #0 Company: 
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1293)
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1260)
    at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:263)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1164)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1050)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:938)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:348)
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:466)
    at Parser.main(Parser.java:102)
--------------- linked to ------------------
javax.xml.xpath.XPathExpressionException: java.io.FileNotFoundException: C:\Users\Dave\Documents\NetBeansProjects\ParseXML\us-patent-grant-v40-2004-12-02.dtd (The system cannot find the file specified)
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:473)
    at Parser.main(Parser.java:102)
Caused by: java.io.FileNotFoundException: C:\Users\Dave\Documents\NetBeansProjects\ParseXML\us-patent-grant-v40-2004-12-02.dtd (The system cannot find the file specified)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:131)
    at java.io.FileInputStream.<init>(FileInputStream.java:87)
    at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
    at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:616)
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1293)
    at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1260)
    at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:263)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1164)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1050)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:938)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:348)
    at com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:466)

有人可以帮我弄清楚我应该做些什么来解析字符串中的文档吗？

Answer 1

尝试设置功能或提供空的EntityResolver

对于功能，您需要找到您使用的解析器实现（它们是特定于实现的）

Make DocumentBuilder.parse ignore DTD references

Answer 2

您是否尝试过提供尝试引用的DTD文件，例如从us-patent-application-v40-2004-12-02.dtd下载？

您可以尝试将此文件放在与XML相同的文件夹中;或者在解析过程的当前目录中（尝试两者，因为你匆忙）。

XPath代码创建IOException

2 个答案: