pop3.java

java的简单例子

package jws.net;

// Copyright 1997, John Webster Small
// All rights Reserved

import java.io.*;
import java.util.*;
import java.net.*;

public class POP3 implements Serializable
{
  protected String server;
  protected int port;

  /** Default POP3 port is 110. */
  public final static int defaultPort = 110;

  protected String user;
  protected String password;

  private String response = "";

  public String getResponse() { return response; }

  protected POP3()
  {
    server = user = password = "";
    port = defaultPort;
  }

  public POP3
    (String server, int port, String user, String password)
  {
    this.server = server;
    this.port = port;
    this.user = user;
    this.password = password;
  }

  public POP3(String server, String user, String password)
    { this(server,defaultPort,user,password); }

  public Vector readMail(boolean deleteOnServer)
    throws IOException, UnknownHostException
  {
    boolean ok;
    int messageCount = 0;
    Vector messages = new Vector();
    Socket s = null;
    BufferedReader in = null;
    PrintWriter out = null;
    try  {
      s = new Socket(server,port);
      in = new BufferedReader
        (new InputStreamReader(s.getInputStream()));
      out = new PrintWriter
        (new BufferedOutputStream(s.getOutputStream()));
      response = in.readLine();
System.out.println(response);
      ok = response.startsWith("+OK");
      if (!ok)
        throw new IOException(response);
      out.println("USER " + user);
      out.flush();
      response = in.readLine();
      ok = response.startsWith("+OK");
      if (!ok)
        throw new IOException(response);
      out.println("PASS " + password);
      out.flush();
      response = in.readLine();
      ok = response.startsWith("+OK");
      if (!ok)
        throw new IOException(response);
      out.println("STAT");
      out.flush();
      response = in.readLine();
      ok = response.startsWith("+OK");
      if (!ok)
        throw new IOException(response);
      StringTokenizer st = new StringTokenizer(response," ");
      if (!st.hasMoreTokens())
        throw new IOException("STAT error: " + response);
      st.nextToken();
      if (!st.hasMoreTokens())
        throw new IOException("STAT error: " + response);
      messageCount = Integer.parseInt(st.nextToken());
      for (int i = 1; i <= messageCount; i++)  {
        Email msg = new Email();
        messages.addElement(msg);
        out.println("RETR "+ i);
        out.flush();
        String buf = in.readLine();
        if (buf.startsWith("+OK")) {
          while (msg.insertHeaderLine(in.readLine()));
          Vector body = new Vector();
          buf = in.readLine();
          while (!buf.equals(".")) {
            if (buf.startsWith("."))
              body.addElement(buf.substring(1));
            else
              body.addElement(buf);
            buf = in.readLine();
          }
          if (body.size() > 0)
            msg.attachBody(body);
        }
      }
      if (deleteOnServer)
        for (int i = 1; i <= messageCount; i++)  {
          out.println("DELE " + i);
          out.flush();
          in.readLine();
        }
    } finally  {
      if (in != null)
        in.close();
      if (out != null)
        out.close();
      if (s != null)
        s.close();
    }
    return messages;
  }
}