Listen for a file?

Question

Hi, i am trying to implement a java program that processes a xml file in a virtual directory. I need to, some how, run a java program that listens for a xml file that is uploaded from one server to a virtual directory on another server where the code is listening. I don't really know where to start with the listening code, and needed some help in the general direction of how to do it. Also i was thinking that when a file is found it is processed using a new thread so that the main thread can carry on listening. Would this be feasible?

Answer 1

Is this more or less what you had in mind?import java.io.*;
public class Monitor1 extends Thread {
     private     static String path = "D:\\Ready";
     private static final int DELAY = 5000;               // 5 second delay
     public void run() {
          while(true) {
               try {
                    File f = new File(path);
                    File controls[] = f.listFiles();
                    for (int i=0; i<controls.length; i++) {
                         BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(controls)));
                         String s = "";
                         java.util.List al = new java.util.ArrayList();
                         while((s=br.readLine()) != null) {
                              al.add(s);
                         Thread c = new ProcessControl(al, path.substring(0, path.indexOf(File.separator)), controls[i].toString());
                         c.start();
                         al = null;
                         br.close();
                         controls[i].delete();
                    sleep(DELAY);
               catch (InterruptedException ie) {}
               catch (IOException ioe) {}
     public static void main(String[] args) {
/*     Sets the control file directory (if specified).               */
          if (args.length > 0) {
               path = args[0];
          Thread mon = new Monitor1();
          mon.start();
class ProcessControl extends Thread {
     private static final String fs = File.separator;
     private String[] values;
     private java.util.ListIterator li;
     private String drive = null;
     private java.util.List al;
     private String file;
     ProcessControl(java.util.List al, String drive, String file) {
          this.file = file;
          this.drive = drive;
          this.al = al;
          li = al.listIterator();
     public void run() {
values = new String[al.size()];
/*     Download the file to the server                                   */
          downloadFile();
     private void downloadFile() {
/*     Downloads the file using FTP protocol                         */
          String uid = "????????";
          String pswd = "????????";
          String server="host";
          try {
               sun.net.ftp.FtpClient client = new sun.net.ftp.FtpClient();
               client.openServer(server);
               client.login(uid, pswd);
               client.cd("path");
               sun.net.TelnetInputStream in = client.get("name of file to be retrieved");
               BufferedReader br = new BufferedReader(new InputStreamReader(in));
               String s;
               while((s=br.readLine()) != null) {
                    System.out.println(s);
               in.close();
          catch (IOException ioe) {
               ioe.printStackTrace();
Mark