smtpconnection.java

自己写的java版的mailclient

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

/**
 * smtp connection class 
 * 
 * @author zyp03
 *
 */
public class SMTPConnection {
    /* The socket connected to server*/
	private Socket connection;
    /*streams for reading and writing the socket*/
	private BufferedReader fromServer;
	private DataOutputStream toServer;
	
	/* BASE 64 decode*/
	//private String username = "MDM2MTEwOA==";
	//private String pass = "MTk4NDcyNg==";
	
	/* static final data*/
	private String server = "localhost";
	private int port = 25;
	private static final String CRLF = "\r\n";
	/* flag to sigh whether connected */
	private boolean connected = false;
	/* create an SMTPConnection object.Create the socket and the associated
	 * streams.
	 * constructor
	 */
	public SMTPConnection (Envelope envelope)throws IOException{
		
		/*set up the connection and in out streams */
		try{
		if(connected==false){
			connection = new Socket (server,port);
		}	
		fromServer = new BufferedReader(
				new InputStreamReader(connection.getInputStream()));
		toServer = new DataOutputStream(connection.getOutputStream());
		}
		catch(IOException ex){
			System.out.print(ex);
			throw ex;
		}
		/* check the reply code*/
		String reply = fromServer.readLine();
		int code = parseReply(reply);
		if(code != 220){
			throw new IOException();
		}
		//String localhsot = "10.130.204.244";
		sendCommand("HELO "+server,250);
		//sendCommand("AUTH LOGIN "+username,334);
		//sendCommand(pass,235);
		connected = true;
	}
	/**
	 * send the message
	 * @param envelope envelope contain all the message 
	 * @throws IOException 
	 */
	public void send(Envelope envelope)throws IOException{
		/*
		 * send the message using sendcommand
		 */
		String command = "MAIL FROM: " + envelope.sender;
		sendCommand(command,250);
		command = "RCPT TO: " + envelope.recipient;
		sendCommand(command,250);
		command = "DATA " + CRLF;
		sendCommand(command,354);
		command = "Subject:"+envelope.message.subject+CRLF;
		
		command += envelope.message.body+CRLF+"."+CRLF;
		sendCommand(command,250);
		
	}
	/**
	 * close the connection 
	 *
	 */
	public void close(){
		try{
			sendCommand("QUIT",221);
			connection.close();
			connected = false;
		}catch(Exception e){
			System.out.println("COLOSE FAILED...");
		}
		
	}
	/**
	 * send an smtp command to the server and checke the reply code 
	 * @param command
	 * @param rc
	 * @throws IOException
	 */
	private void sendCommand(String command,int rc)throws IOException{
		// format the command sent to server
		
		command += CRLF ;	
		System.out.print(command);
		toServer.writeBytes(command);
		
		/*get the reply*/
		String reply = fromServer.readLine();
		int code = parseReply(reply);
		if(code == rc){
			return ;
		}
		else 
			throw new IOException(command);
			
		/*
		    DATA  354 
			HELO  250 
			MAIL FROM  250 
			QUIT  221 
			RCPT TO  250 

		 */
		
	}
	/**
	 * parse the reply from the server return the reply code 
	 * @param reply
	 * @return
	 */
	private int parseReply(String reply){
		StringTokenizer tokens = new StringTokenizer(reply);
		int code = 0;
		try{
			code = Integer.parseInt(tokens.nextToken());
		}
		catch(Exception e){
			code = -1;
		}
		return code;
	}
	/**
	 * destructor.closes the connection if fail
	 */
	protected void finalize()throws Throwable{
		close();
	}
	

}