import java.util.Vector;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ListManagerServlet extends HttpServlet
{
private Vector addresses;
private String filename;
public void init(ServletConfig config) throws ServletException
{
super.init(config);
filename = config.getInitParameter("addressfile");
if(filename == null)
throw new UnavailableException(this,
"The \"addressfile\" property "+
"must be set to a file name");
try
{
ObjectInputStream in =
new ObjectInputStream(new FileInputStream(filename));
addresses = (Vector)in.readObject();
in.close();
}
catch(FileNotFoundException e) { addresses = new Vector(); }
catch(Exception e)
{
throw new UnavailableException(this,
"Error reading address file: "+e);
}
}
protected void doGet(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException
{
res.setContentType("text/html");
res.setHeader("pragma", "no-cache");
PrintWriter out = res.getWriter();
out.print("List Manager");
out.print("Members:
");
for(int i=0; i" + addresses.elementAt(i));
out.print("
");
out.close();
}
protected void doPost(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException
{
String email = req.getParameter("email");
String msg;
if(email == null)
{
res.sendError(res.SC_BAD_REQUEST,
"No email address specified.");
return;
}
if(req.getParameter("action").equals("subscribe"))
{
if(subscribe(email))
msg = "Address " + email + " has been subscribed.";
else
{
res.sendError(res.SC_BAD_REQUEST,
"Address " + email + " was already subscribed.");
return;
}
}
else
{
if(unsubscribe(email))
msg = "Address " + email + " has been removed.";
else
{
res.sendError(res.SC_BAD_REQUEST,
"Address " + email + " was not subscribed.");
return;
}
}
res.setContentType("text/html");
res.setHeader("pragma", "no-cache");
PrintWriter out = res.getWriter();
out.print("List Manager");
out.print(msg);
out.print("
Show the list");
out.close();
}
public String getServletInfo()
{
return "ListManagerServlet 1.0 by Stefan Zeiger";
}
private synchronized boolean subscribe(String email) throws IOException
{
if(addresses.contains(email)) return false;
addresses.addElement(email);
save();
return true;
}
private synchronized boolean unsubscribe(String email) throws IOException
{
if(!addresses.removeElement(email)) return false;
save();
return true;
}
private void save() throws IOException
{
ObjectOutputStream out =
new ObjectOutputStream(new FileOutputStream(filename));
out.writeObject(addresses);
out.close();
}
}