package group2.shenyang;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/*************************************************************************
Name: POP.java
Input:
3 parameters from a CGI form w/ the following names
user: username
pass: password
host: host to retrieve mail from
Functionality:
- Parses the input
- Log into POP server on the appropriate machine
- Find out how many emails the user has
- If the TOP command is supported on the POP server, retrieve the Subject,
From, To, and Date info for each email
- Log out from the server
Output:
An HTML page that includes a link for each email (calls RetrieveMail.java),
and the option to delete each email (calls Update.java).
Error Checks:
- Missing/incorrect username, password, or host.
- POP server not responding.
**************************************************************************/
public class POP extends HttpServlet{
/* Warn the CGI Form author that the POST method is preferred so that
* the user password is not being displayed on the URL line
*/
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException{
res.setContentType("text/html");
ServletOutputStream out=res.getOutputStream();
out.println("Please use POST method");
out.println("Please use POST method for your CGI form for SECURITY reasons
");
}
/* The doPost class will handle the request */
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException{
res.setContentType("text/html");
ServletOutputStream out=res.getOutputStream();
try{
// ======= Get the parameters from the CGI form =======
String user=req.getParameter("user");
String pass=req.getParameter("pass");
String host=req.getParameter("host");
if (user.equals("")){
throw new ServletException("Missing Username");
}
if (pass.equals("")){
throw new ServletException("Missing Password");
}
if (host.equals("")){
throw new ServletException("Missing Hostname");
}
// ===== Create socket and log into POP3 =====
Socket sock=new Socket(host, 110);
PrintStream in_sock=new PrintStream(sock.getOutputStream());
DataInputStream out_sock=new DataInputStream(sock.getInputStream());
String pop_res;
pop_res=out_sock.readLine();
if (! pop_res.startsWith("+OK")){
throw new ServletException("POP3 Server Not Ready");
}
in_sock.println("USER "+user);
pop_res=out_sock.readLine();
if (! pop_res.startsWith("+OK")){
throw new ServletException("Incorrect Username");
}
in_sock.println("PASS "+pass);
pop_res=out_sock.readLine();
if (! pop_res.startsWith("+OK")){
throw new ServletException("Incorrect Password");
}
// ======== Figure out how many emails ===========
StringTokenizer num_msg=new StringTokenizer(pop_res, " ");
num_msg.nextToken(); //+OK
num_msg.nextToken(); //username
num_msg.nextToken(); //has
int msg=Integer.parseInt(num_msg.nextToken()); //number of msgs
// ===== Retrive msgs into files if nummsg!=0 =====
if (msg == 0){
out.println("");
out.println("Email for "+user+" on "+host+"");
out.println("Email for "+user+" on "+host+"
");
out.println("You have 0 new mails!");
}
else{
// HTML tags
out.println("");
out.println("Email for "+user+" on "+host+"");
out.println("Email for "+user+" on "+host+"
");
out.println("You have "+msg+" new mail(s)!
");
out.println("");
}
in_sock.println("QUIT");
}
catch (ServletException e){
out.println(""+e+"");
out.println(""+e+"");
}
catch (UnknownHostException e){
out.println("Unknown Host");
out.println(""+e+"
");
out.println("The hostname you supplied is unknown, try again!");
out.println("");
}
catch (IOException e){
out.println("IOException");
out.println(""+e+"
");
out.println("");
}
}
}