pop3store.java

java 开发的一个电子邮局,挺实用的

/*
 * POP3Store.java
 * Copyright (C) 1999 dog <[e-mail]>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * You may retrieve the latest version of this library from
 * http://www.dog.net.uk/knife/
 */

package dog.mail.pop3;

import java.io.*;
import java.net.*;
import javax.mail.*;
import javax.mail.event.*;
import dog.mail.util.*;

/**
 * The storage class implementing the POP3 mail protocol.
 *
 * @author [e-mail]
 * @version 1.1
 */
public class POP3Store extends Store {

	/**
	 * The default POP3 port.
	 */
	public static final int DEFAULT_PORT = 110;

	static int fetchsize = 1024;
	
	Socket socket;
	CRLFInputStream in;
	CRLFOutputStream out;
	String hostname; // the server hostname

	static int OK = 0, ERR = -1; // response codes
	String response; // last response

	POP3Folder root; // the root folder

	/**
	 * Constructor.
	 */
	public POP3Store(Session session, URLName urlname) {
		super(session, urlname);
		String ccs = session.getProperty("mail.pop3.fetchsize");
		if (ccs!=null) try { fetchsize = Math.max(Integer.parseInt(ccs), 1024); } catch (NumberFormatException e) {}
	}
	
	/**
	 * Connects to the POP3 server and authenticates with the specified parameters.
	 */
	protected boolean protocolConnect(String host, int port, String username, String password) throws MessagingException {
        if (port<0) port = DEFAULT_PORT;
		if (host==null || username==null || password==null)
			return false;
		if (socket!=null)
			return true;
		synchronized (this) {
			try {
				hostname = host;
				socket = new Socket(host, port);
				in = new CRLFInputStream(socket.getInputStream());
				out = new CRLFOutputStream(socket.getOutputStream());
				if (getResponse()!=OK)
					throw new MessagingException("Connect failed. Server responded: "+response);
				int index = response.indexOf(' ');
				if (index>-1) hostname = response.substring(0, index);
				send("USER "+username);
				if (getResponse()!=OK)
					throw new MessagingException("Connect failed. Server responded: "+response);
				send("PASS "+password);
				if (getResponse()!=OK)
					throw new MessagingException("Connect failed. Server responded: "+response);
				return true;
			} catch(UnknownHostException e) {
				throw new MessagingException("Connect failed", e);
			} catch(IOException e) {
				throw new MessagingException("Connect failed", e);
			}
		}
	}

	/**
	 * Closes the connection.
	 */
	public synchronized void close() throws MessagingException {
		if (socket!=null) {
			synchronized (this) {
				try {
					send("QUIT");
					if (getResponse()!=OK)
						throw new MessagingException("Close failed: "+response);
					socket.close();
					socket = null;
				} catch (IOException e) {
					// socket.close() always seems to throw an exception!
					//throw new MessagingException("Close failed", e);
				}
			}
		}
		super.close();
			
	}

	private int getResponse() throws IOException {
		String okstr = "+OK", errstr = "-ERR";
		response = in.readLine();
		if (response.indexOf(okstr)==0) {
			response = response.substring(okstr.length()).trim();
			return OK;
		} else if (response.indexOf(errstr)==0)
			response = response.substring(errstr.length()).trim();
		return ERR;
	}

	private void send(String command) throws IOException {
		out.write(command.getBytes());
		out.writeln();
		out.flush();
	}

	String getHostName() { return hostname; }

	synchronized int getMessageCount() throws MessagingException {
		try {
			send("STAT");
			if (getResponse()!=OK)
				throw new MessagingException("Status failed. Server responded: "+response);
			try {
				return Integer.parseInt(response.substring(0, response.indexOf(' ')));
			} catch(NumberFormatException e) {
				throw new MessagingException("Status failed. Server responded: "+response);
			}
		} catch (IOException e) {
			throw new MessagingException("Status failed.", e);
		}
	}

	synchronized Message getMessage(POP3Folder folder, int msgnum) throws MessagingException {
		//int length = -1;
		try {
			send("RETR "+msgnum);
			if (getResponse()!=OK)
				throw new MessagingException("Retrieve failed. Server responded: "+response);
			//length = Integer.parseInt(response.substring(0, response.indexOf(' '))); // sod all use, it's always wrong
            return new POP3Message(folder, new MessageInputStream(in), msgnum);
		} catch (IOException e) {
			throw new MessagingException("Retrieve failed.", e);
		} catch (NumberFormatException e) {
			throw new MessagingException("Retrieve failed.", e);
		}
	}

	synchronized void delete(int msgnum) throws MessagingException {
		try {
			send("DELE "+msgnum);
			if (getResponse()!=OK)
				throw new MessagingException("Delete failed. Server responded: "+response);
		} catch (IOException e) {
			throw new MessagingException("Delete failed.", e);
		}
	}

	/**
	 * Returns the root folder.
	 */
	public Folder getDefaultFolder() throws MessagingException {
		synchronized (this) {
			if (root==null) root = new POP3Folder(this, Folder.HOLDS_FOLDERS);
		}
		return root;
	}

	/**
	 * Returns the folder with the specified name.
	 */
	public Folder getFolder(String s) throws MessagingException {
        return getDefaultFolder().getFolder(s);
	}

	/**
	 * Returns the folder whose name is the file part of the specified URLName.
	 */
	public Folder getFolder(URLName urlname) throws MessagingException {
        return getDefaultFolder().getFolder(urlname.getFile());
	}

}