User Interface Class

import org.xml.sax.*;
import org.xml.sax.helpers.*;
import java.util.*;
import java.io.*;

public class Weblogs {
     
  public static List listChannels() 
   throws IOException, SAXException {
    return listChannels(
     "http://static.userland.com/weblogMonitor/logs.xml"); 
  }
  
  public static List listChannels(String uri) 
   throws IOException, SAXException {
    
    // set up the parser 
    XMLReader parser;
    try {
      parser = XMLReaderFactory.createXMLReader();
    } 
    catch (SAXException e) {
      try {
        parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
      }
      catch (SAXException e2) {
        System.err.println("Error: could not locate a parser.");
        return null;
      }
    }
    
    Vector urls = new Vector(1000);
    URIGrabber u = new URIGrabber(urls);
    parser.setContentHandler(u);
    parser.parse(uri);
    return urls;
    
  }
  
  public static void main(String[] args) {
   
    try {
      List urls;
      if (args.length > 0) urls = listChannels(args[0]);
      else urls = listChannels();
      Iterator iterator = urls.iterator();
      while (iterator.hasNext()) {
        System.out.println(iterator.next()); 
      }
    }
    catch (IOException e) {
      System.err.println(e); 
    }
    catch (SAXParseException e) {
      System.err.println(e); 
      System.err.println("at line " + e.getLineNumber() 
       + ", column " + e.getColumnNumber()); 
    }
    catch (SAXException e) {
      System.err.println(e); 
    }
    catch (/* Unexpected */ Exception e) {
      e.printStackTrace(); 
    }
    
  }
  
}