smtp.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 SMTP implements Serializable
{
  protected String server;
  protected int port;

  /** The default SMTP port is 25. */
  public static final int defaultPort = 25;

  protected String senderHost;
  protected String senderEmailAddress;

  private transient String response = "";

  public String getResponse() { return response; }

  protected SMTP()
  {
    server = senderHost = senderEmailAddress = "";
    port = defaultPort;
  }

  public SMTP
    (String server, int port,
     String senderHost, String senderEmailAddress)
  {
    this.server = server;
    this.port = port;
    this.senderHost = senderHost;
    this.senderEmailAddress = senderEmailAddress;
  }

  public SMTP(String server,
    String senderHost, String senderEmailAddress)
  { this(server,defaultPort,senderHost,senderEmailAddress); }

  // return true if at least one addressee makes it
  private boolean RCPT_TO
    (BufferedReader in, PrintWriter out, String[] addresses)
    throws IOException
  {
    boolean atLeastOneRecipient = false;
    for (int i = 0; i < addresses.length; i++)  {
      out.println("RCPT TO:<"
        + Email.addressee(addresses[i]) + ">");
      out.flush();
      response = in.readLine();
      atLeastOneRecipient |= response.startsWith("250");
    }
    return atLeastOneRecipient;
  }

  public void sendMail(Enumeration messages)
    throws IOException, UnknownHostException
  {
    boolean ok;
    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();
      ok = response.startsWith("220");
      if (!ok)
        throw new IOException(response);
      out.println("HELO " + senderHost);
      out.flush();
      response = in.readLine();
      ok = response.startsWith("250");
      if (!ok)
        throw new IOException(response);
      while (messages.hasMoreElements())
      {
        Email msg = (Email) messages.nextElement();
        msg.setFrom(senderEmailAddress);
        msg.postMark();
        out.println("MAIL FROM:<"
          + Email.addressee(msg.getFrom())+">");
        out.flush();
        response = in.readLine();
        ok = response.startsWith("250");
        if (!ok)
          throw new IOException(response);
        boolean atLeastOneRecipient
          = RCPT_TO(in,out,msg.getTo());
        atLeastOneRecipient
          |= RCPT_TO(in,out,msg.getCc());
        atLeastOneRecipient
          |= RCPT_TO(in,out,msg.getBcc());
        if (!atLeastOneRecipient)
          throw new IOException
            ("at least one recipient must be valid");
        out.println("DATA");
        out.flush();
        response = in.readLine();
        ok = response.startsWith("354");
        if (!ok)
          throw new IOException(response);
        Enumeration headers = msg.getHeaders();
        while (headers.hasMoreElements())  {
          out.println((String)headers.nextElement());
          out.flush();
        }
        out.println("");
        out.flush();
        Enumeration body = msg.getBody();
        while (body.hasMoreElements())  {
          String line = (String) body.nextElement();
          if (line.equals("."))
            line = "..";
          out.println(line);
          out.flush();
        }
        out.println(".");
        out.flush();
        response = in.readLine();
        ok = response.startsWith("250");
        if (!ok)
          throw new IOException(response);
      }
      out.println("QUIT");
      out.flush();
    } finally  {
      if (in != null)
        in.close();
      if (out != null)
        out.close();
      if (s != null)
        s.close();
    }
  }
}