/*
 * (C) Copyright IBM Corp. 2004.  All rights reserved.
 *
 * US Government Users Restricted Rights Use, duplication or
 * disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
 *
 * The program is provided "as is" without any warranty express or
 * implied, including the warranty of non-infringement and the implied
 * warranties of merchantibility and fitness for a particular purpose.
 * IBM will not be liable for any damages suffered by you as a result
 * of using the Program. In no event will IBM be liable for any
 * special, indirect or consequential damages or lost profits even if
 * IBM has been advised of the possibility of their occurrence. IBM
 * will not be liable for any third party claims against you.
 */

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.LocatorImpl;

/**
 * A sample SAX application.  This code illustrates how to kill
 * the SAX parser when you've found what you needed from your
 * document.  In this case, we kill the parser after the fourth
 * <line> element is found. 
 */

public class SaxKiller
  extends DefaultHandler 
{
  int lineCount = 0;
  boolean inFourthLine = false;
  StringBuffer fourthLine = new StringBuffer();
  boolean notSuccessful = true;

  public boolean isNotSuccessful()
  {
    return notSuccessful;
  }

  public void parseURI(String uri)
      throws Exception
  {
    SAXParserFactory spf = SAXParserFactory.newInstance();
    SAXParser sp = spf.newSAXParser();
    sp.parse(uri, this);
  }
    
  /** Start element. */
  public void startElement(String namespaceURI, String localName, 
                           String rawName, Attributes attrs) 
  {
    if (rawName.equals("line") && ++lineCount == 4)
        inFourthLine = true;
  } // startElement(String,AttributeList)

  /** Characters. */
  public void characters(char ch[], int start, int length) 
  {
    if (inFourthLine)
      fourthLine.append(new String(ch, start, length));
  } // characters(char[],int,int);

  /** End element. */
  public void endElement(String namespaceURI, String localName, 
                         String rawName) 
    throws SAXException
  {
    if (rawName.equals("line") && inFourthLine)
    {
      System.out.println("\nThe text of the fourth line is: \n");
      System.out.println("\t" + fourthLine);

      notSuccessful = false;
      SAXParseException spe = 
        new SAXParseException("Found the fourth <line>, " + 
                              "so we killed the parser!", 
                              new LocatorImpl());
      fatalError(spe); 
    }
  } // endElement(String)

  //
  // ErrorHandler methods
  //

  /** Warning. */
  public void warning(SAXParseException ex) 
  {
    System.err.println("\n\n[Warning] "+
                       getLocationString(ex)+": "+
                       ex.getMessage());
  }

  /** Error. */
  public void error(SAXParseException ex) 
  {
    System.err.println("\n\n[Error] "+
                       getLocationString(ex)+": "+
                       ex.getMessage());
  }

  /** Fatal error. */
  public void fatalError(SAXParseException ex) 
      throws SAXParseException 
  {
    throw ex;
  }

  /** Returns a string of the location. */
  private String getLocationString(SAXParseException ex) 
  {
    StringBuffer str = new StringBuffer();

    String systemId = ex.getSystemId();
    if (systemId != null)
    {
      int index = systemId.lastIndexOf('/');
      if (index != -1)
        systemId = systemId.substring(index + 1);
      str.append(systemId);
    }
    str.append(':');
    str.append(ex.getLineNumber());
    str.append(':');
    str.append(ex.getColumnNumber());

    return str.toString();
  } // getLocationString(SAXParseException):String

  /** Main program entry point. */
  public static void main(String argv[]) 
  {
    if (argv.length == 0 ||
        (argv.length == 1 && argv[0].equals("-help")))
    {
      System.out.println("\nUsage:  java SaxKiller uri");
      System.out.println("   where uri is the URI of your XML document.");
      System.out.println("   Sample:  java SaxKiller sonnet.xml");
      System.out.println("\nIllustrates how to kill a SAX parser by " + 
                         "throwing an exception.");
      System.exit(1);
    }

    SaxKiller s1 = new SaxKiller();
    try
    {
      s1.parseURI(argv[0]);
    }
    // We're expecting an exception, so we ignore anything that happens...
    catch (Exception e) 
    { 
      if (s1.isNotSuccessful())
        System.err.println(e);
    }
  } // main(String[])
}