Locator Example

import org.xml.sax.*;
import org.xml.sax.helpers.*;
import org.apache.xerces.parsers.*; 
import java.io.*;


public class LocationReporter implements ContentHandler {

  Locator locator = null;

  public void setDocumentLocator(Locator locator) {
    this.locator = locator;  
  }
  
  private String reportPosition() {
    
    if (locator != null) {
      
      String publicID = locator.getPublicId();
      String systemID = locator.getSystemId();
      int line        = locator.getLineNumber();
      int column      = locator.getColumnNumber();
      
      String name;
      if (publicID != null) name = publicID;
      else name = systemID;
      
      return " in " + name + " at line " + line 
       + ", column " + column;
    }
    return "";
    
  }
  
  public void startDocument() throws SAXException {
    System.out.println("Document started" + reportPosition()); 
  }

  public void endDocument() throws SAXException {
    System.out.println("Document ended" + reportPosition()); 
  }
  
  public void characters(char[] text, int start, int length) 
   throws SAXException {
    System.out.println("Got some characters" + reportPosition()); 
  }
  
  public void ignorableWhitespace(char[] text, int start, int length)
   throws SAXException {
    System.out.println("Got some ignorable white space" 
     + reportPosition()); 
  }
  
  public void processingInstruction(String target, String data)
   throws SAXException {
    System.out.println("Got a processing instruction" 
     + reportPosition()); 
  }
  
  // Changed methods for SAX2
  public void startElement(String namespaceURI, String localName,
	 String qualifiedName, Attributes atts) throws SAXException {
    System.out.println("Element " + qualifiedName + " started" 
     + reportPosition()); 
  }
  
  public void endElement(String namespaceURI, String localName,
	 String qualifiedName) throws SAXException {
    System.out.println("Element " + qualifiedName + " ended" 
     + reportPosition()); 
  } 

  // new methods for SAX2
  public void startPrefixMapping(String prefix, String uri) 
   throws SAXException {
    System.out.println("Started mapping prefix " + prefix 
     + " to URI " + uri + reportPosition());     
  }

  public void endPrefixMapping(String prefix) throws SAXException {
    System.out.println("Stopped mapping prefix " 
     + prefix + reportPosition());         
  }

  public void skippedEntity(String name) throws SAXException {
    System.out.println("Skipped entity " + name + reportPosition());         
  }  

  // Could easily have put main() method in a separate class
  public static void main(String[] args) {
    
    XMLReader parser;
    try {
      parser = XMLReaderFactory.createXMLReader();
    }
    catch (SAXException ex) {
      try {
        parser = XMLReaderFactory.createXMLReader(
         "org.apache.xerces.parsers.SAXParser");
      }
      catch (SAXException e2) {
        System.err.println("Error: no parser found!");
        return; 
      }
    }
     
    if (args.length == 0) {
      System.out.println(
       "Usage: java LocationReporter URL1 URL2..."); 
    } 
      
    // Install the Content Handler      
    parser.setContentHandler(new LocationReporter());
    
    // start parsing... 
    for (int i = 0; i < args.length; i++) {
      
      // command line should offer URIs or file names
      try {
        parser.parse(args[i]);
      }
      catch (SAXParseException e) { // well-formedness error
        System.out.println(args[i] + " is not well formed.");
        System.out.println(e.getMessage()
         + " at line " + e.getLineNumber() 
         + ", column " + e.getColumnNumber());
      }
      catch (SAXException e) { // some other kind of error
        System.out.println(e.getMessage());
      }
      catch (IOException e) {
        System.out.println("Could not report on " + args[i] 
         + " because of the IOException " + e);
      }
      
    }  
  
  }

}