socketmail.java

基于JavaMail开发的E-mail系统

import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.IOException;
import java.net.Socket;

public class SocketMail {

	public static void send(String smtpHost, String sender, String recipients,
					  String subject, String msg) {

		Socket mailSocket;
		BufferedReader is;
		PrintWriter outToServer;

		try {
			// Step 1:  Connect to SMTP server
			System.out.println("opening connection to server: " + smtpHost);
			mailSocket = new Socket(smtpHost, 25);
			System.out.println("connected");

			// Step 2:  Get an output stream for the socket connection
			outToServer= new PrintWriter (mailSocket.getOutputStream());

			// Step 3:  Compose the message using the SMTP commands
			System.out.println("composing message");
			outToServer.println("MAIL FROM: <" + sender + ">");
			outToServer.println("RCPT TO: <" + recipients + ">");
			outToServer.println("DATA");
			outToServer.println("SUBJECT: " + subject);
			outToServer.println("X-Mailer: SocketMail");
			outToServer.println(msg);
			outToServer.println(".\n");

			outToServer.flush();
			mailSocket.close();
			System.out.println("message sent");
		}
		catch (IOException exc)
		{
			System.out.println(exc);
		}
	}

	public static void main(String[] args) {
		if (args.length != 3) {
			System.out.println("Usage:  java SocketMail <smtphost> <from> <to>");
			System.exit(1);
		}

		String smtpHost = args[0];
		String from = args[1];
		String to = args[2];
		String subject = "Test Message";
		StringBuffer theMessage = new StringBuffer();
		theMessage.append("Hello,\n\n");
		theMessage.append("Hope all is well.\n");
		theMessage.append("Cheers!");

		SocketMail.send(smtpHost, from, to, subject, theMessage.toString());
	}
}