SAX Error Checking: A Simple Implementation of the ErrorHandler Interface : SAX « XML « Java Tutorial

1. Java Tutorial
2. XML
3. SAX

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

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

class MyErrorHandler implements ErrorHandler {
  public void warning(SAXParseException e) throws SAXException {
    show("Warning", e);
    throw (e);
  }

  public void error(SAXParseException e) throws SAXException {
    show("Error", e);
    throw (e);
  }

  public void fatalError(SAXParseException e) throws SAXException {
    show("Fatal Error", e);
    throw (e);
  }

  private void show(String type, SAXParseException e) {
    System.out.println(type + ": " + e.getMessage());
    System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
    System.out.println("System ID: " + e.getSystemId());
  }
}

// Installation and Use of an Error Handler in a SAX Parser

public class SAXCheck {
  static public void main(String[] arg) throws Exception {
    boolean validate = false;
    validate = true;

    SAXParserFactory spf = SAXParserFactory.newInstance();
    spf.setValidating(validate);

    XMLReader reader = null;
    SAXParser parser = spf.newSAXParser();
    reader = parser.getXMLReader();

    reader.setErrorHandler(new MyErrorHandler());
    InputSource is = new InputSource("test.xml");
    reader.parse(is);
  }
}

Error: Document root element "roots", must match DOCTYPE root "null".
Line 1 Column 8
System ID: file:///C:/Java_Dev/eclipse31/Eclipse/test.xml

//File: test.xml
<roots>
  <a>
    <b>text</b>
  </a>
</roots>