如何在 Java 中使用 "Opening and ending tag mismatch" 解析 XML 文件

Question

我有 XML 带有公开价格标签的文件。尽管有错误，有没有办法解析文件？如何跳过错误的产品并继续解析？

<Products>
      <Product Name="Gummi bears">
        <Price Currency="GBP">4.07</Price>
        <BestBefore Date="19-02-2014"/>
      </Product>
      <Product Name="Mounds">
        <Price Currency="AUD">5.64
        <BestBefore Date="08-04-2014"/>
      </Product>
      <Product Name="Vodka">
        <Price Currency="RUB">70</Price>
        <BestBefore Date="11-10-2014"/>
      </Product>
  </Products>

Answer 1

处理此类错误的一般方法是使用流分析器。 Java 想到的是 SAX。

创建处理程序时，您将能够override/implement error and fatalError 方法。这些将允许您继续解析，但仍然需要您处理实际错误。

显然，XML 文档中可能存在许多错误，只有处理其中一些才有意义。不过，希望这会给您一个开始解析器的地方。

Answer 2

这是代码。这是 BrandonArp 已经提到的实现。

有一个属性需要设置为忽略致命错误 - continue-after-fatal-error

http://apache.org/xml/features/continue-after-fatal-error 
true:   Attempt to continue parsing after a fatal error.  
false:  Stops parse on first fatal error.  
default:    false  
XMLUni Predefined Constant:     fgXercesContinueAfterFatalError  
note:   The behavior of the parser when this feature is set to true is undetermined! Therefore use this feature with extreme caution because the parser may get stuck in an infinite loop or worse.

可以找到更多详细信息here

PriceReader class

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.XMLReader;

public class PriceReader {

    public static void main(String argv[]) {

        try {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        SAXParser saxParser = factory.newSAXParser();

        XMLReader xmlReader = saxParser.getXMLReader();

        try {
            xmlReader.setFeature(
                            "http://apache.org/xml/features/continue-after-fatal-error",
                            true);
        } catch (SAXException e) {
            System.out.println("error in setting up parser feature");
        }

        xmlReader.setContentHandler(new PriceHandler());
        xmlReader.setErrorHandler(new MyErrorHandler());
        xmlReader.parse("bin\com\test\stack\overflow\sax\prices.xml");

    } catch (Throwable e) {
         System.out.println("Error -- " +e.getMessage());
    }

    }
}

PriceHandler class

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class PriceHandler extends DefaultHandler {

    public void startElement(String uri, String localName,
        String qName, Attributes attributes)
        throws SAXException {

    if (qName.equalsIgnoreCase("Product")) {
        System.out.println("Product ::: "+ attributes.getValue("Name"));
    }
  }
}

MyErrorHandler class

import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

public class MyErrorHandler implements ErrorHandler {

    private String getParseExceptionInfo(SAXParseException spe) {
        String systemId = spe.getSystemId();

        if (systemId == null) {
            systemId = "null";
        }

        String info = "URI=" + systemId + " Line=" 
            + spe.getLineNumber() + ": " + spe.getMessage();

        return info;
    }

    public void warning(SAXParseException spe) throws SAXException {
        System.out.println("Warning: " + getParseExceptionInfo(spe));
    }

    public void error(SAXParseException spe) throws SAXException {
        String message = "Error: " + getParseExceptionInfo(spe);
        System.out.println(message);
    }

    public void fatalError(SAXParseException spe) throws SAXException {
        String message = "Fatal Error: " + getParseExceptionInfo(spe);
        System.out.println(message);
    }
}

Output

 Product ::: Gummi bears
Product ::: Mounds
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=9: The element type "Price" must be terminated by the matching end-tag "</Price>".
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=9: The end-tag for element type "Price" must end with a '>' delimiter.
Product ::: Vodka
Product ::: Rum
Product ::: Brezzer
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=21: The element type "Price" must be terminated by the matching end-tag "</Price>".
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=21: The end-tag for element type "Price" must end with a '>' delimiter.
Product ::: Water
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=26: The end-tag for element type "Product" must end with a '>' delimiter.
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=26: XML document structures must start and end within the same entity.
Fatal Error: URI=file:///C:/Developer/pachat/workspaces/eclipse-default/stack-overflow/bin/com/test/stack/overflow/sax/prices.xml Line=26: Premature end of file.
 Error -- processing event: -1

如何在 Java 中使用 "Opening and ending tag mismatch" 解析 XML 文件

How to parse XML file with "Opening and ending tag mismatch" in Java

java

xml

tags

parsing