Solution to solve Java XML parsing error exception (XMLParsingErrorExceotion)

Solution to solve Java XML parsing error exception (XMLParsingErrorException)

In the Java development process, XML is often used to store and transfer data. However, due to the complexity and syntax specifications of XML, XML parsing error exceptions (XMLParsingErrorException) sometimes occur. This article describes some common solutions and provides corresponding code examples.

1. Verify the format of XML files
   XML files must conform to a specific format, including correct tag closure, correct attribute format, etc. Using XML validation tools can help check whether the XML file is formatted correctly.

The following is a code example for XML format verification using Java:

import javax.xml.XMLConstants;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;
import org.xml.sax.SAXException;
import java.io.File;
import java.io.IOException;

public class XMLValidator {

    public static void main(String[] args) {
        String xmlFilePath = "path/to/xml/file.xml";
        String xsdFilePath = "path/to/xsd/file.xsd";

        boolean isValid = validateXML(xmlFilePath, xsdFilePath);
        System.out.println("XML文件是否有效: " + isValid);
    }

    public static boolean validateXML(String xmlFilePath, String xsdFilePath) {
        try {
            Source xmlFile = new StreamSource(new File(xmlFilePath));
            SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            Schema schema = schemaFactory.newSchema(new File(xsdFilePath));
            Validator validator = schema.newValidator();
            validator.validate(xmlFile);
            return true;
        } catch (SAXException | IOException e) {
            e.printStackTrace();
            return false;
        }
    }
}

2. Check the version of the XML parser
   Parsing of XML by different versions of XML parsers The rules may vary, causing parsing errors. Make sure that the version of the XML parser you use is compatible with the format of the XML file.

The following is a code example for using DOM to parse XML:

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;
import java.io.File;

public class XMLParser {

    public static void main(String[] args) {
        String xmlFilePath = "path/to/xml/file.xml";

        parseXML(xmlFilePath);
    }

    public static void parseXML(String xmlFilePath) {
        try {
            File xmlFile = new File(xmlFilePath);
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
            Document doc = dBuilder.parse(xmlFile);
            doc.getDocumentElement().normalize();

            NodeList nodeList = doc.getElementsByTagName("tag");
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node node = nodeList.item(i);

                if (node.getNodeType() == Node.ELEMENT_NODE) {
                    Element element = (Element) node;
                    // 处理节点数据
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3. Handling specific XML parsing error exceptions
   In addition to regular XML parsing error exceptions, sometimes A specific XML parsing error exception will occur. For example, processing when illegal characters or special characters are encountered, etc. Perform corresponding processing based on specific exception information, such as filtering unparsable characters or using specific character encoding.

The following is a code example for handling illegal characters:

import org.xml.sax.*;
import org.xml.sax.helpers.XMLFilterImpl;

import java.io.IOException;

public class IllegalCharacterFilter extends XMLFilterImpl {

    public void characters(char[] ch, int start, int length) throws SAXException {
        for (int i = start; i < start + length; i++) {
            if (Character.isHighSurrogate(ch[i]) || Character.isLowSurrogate(ch[i])) {
                // 过滤非法字符
                ch[i] = 'uFFFD';
            }
        }
        super.characters(ch, start, length);
    }
}

Use this filter:

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import java.io.File;

public class XMLParser {

    public static void main(String[] args) {
        String xmlFilePath = "path/to/xml/file.xml";

        parseXML(xmlFilePath);
    }

    public static void parseXML(String xmlFilePath) {
        try {
            File xmlFile = new File(xmlFilePath);
            InputSource inputSource = new InputSource(xmlFile.toURI().toString());

            SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
            SAXParser saxParser = saxParserFactory.newSAXParser();
            XMLReader xmlReader = saxParser.getXMLReader();
            xmlReader.setContentHandler(new MyContentHandler());
            xmlReader.setErrorHandler(new MyErrorHandler());
            xmlReader.parse(inputSource);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

It should be noted that the above code only provides some common Solutions and examples may vary depending on specific needs and exceptions. Therefore, when handling XML parsing error exceptions, appropriate adjustments and processing need to be made based on the actual situation.

Summary:
This article introduces some solutions to solve Java XML parsing error exceptions and provides corresponding code examples. By verifying the format of XML files, checking the version of the XML parser, and handling specific XML parsing error exceptions, Java XML parsing error exceptions can be effectively solved and the reliability and stability of the program can be improved. Readers are advised to make appropriate adjustments and treatments based on specific circumstances in practice.

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