Exemple

Упражнение: Копирайте локално няколко WEB страници. WEB страниците и имената на съответстващите файлове се намират в файл с име url-list.txt в следващата форма:

http://www.refg.tu-sofia.bg/JavaBg Java.html
http://yahoo.com yahoo.html

import java.util.Vector;
import java.io.*;
import java.net.*;
public class WebFetchApp {
   public static void main(String args[]){
        WebFetch fetch = new WebFetch();
        fetch.run();
   }
}
class WebFetch {
String urlList = "url-list.txt";
Vector URLs = new Vector();
Vector fileNames = new Vector();
public void getURLList() {
   try {
      BufferedReader inStream = new BufferedReader(new FileReader(urlList));
      String inLine;
      while((inLine = inStream.readLine()) != null) {
          inLine = inLine.trim();
          if(!inLine.equals("")) {
              int tabPos = inLine.lastIndexOf('\t');
              String url = inLine.substring(0,tabPos).trim();
              String fileName = inLine.substring(tabPos+1).trim();
              URLs.addElement(url);
              fileNames.addElement(fileName);
          }
      }
   } catch(IOException ex){
         error("Error reading "+urlList);
      }
} public void run() {
getURLList();
int numURLs = URLs.size();
for(int i=0;i<numURLs;++i)
   fetchURL((String) URLs.elementAt(i),(String) fileNames.elementAt(i));
System.out.println("Done.");
}
public void fetchURL(String urlName,String fileName) {
try{
   URL url = new URL(urlName);
   System.out.println("Getting "+urlName+"...");
   File outFile = new File(fileName);
   PrintWriter outStream = new PrintWriter(new FileWriter(outFile));
   BufferedReader inStream = new BufferedReader(
    new InputStreamReader(url.openStream()));
   String line;
   while ((line = inStream.readLine())!= null) outStream.println(line);
   inStream.close();
   outStream.close();
}catch (MalformedURLException ex){
   System.out.println("Bad URL");
}catch (IOException ex){
   System.out.println("IOException occurred.");
}
}
public void error(String s){
System.out.println(s);
System.exit(1);
}
}