/*
* Copyright 2001-2005 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.pop3;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.lang.StringBuffer;
import java.util.Enumeration;
import java.util.Vector;
import org.apache.commons.net.MalformedServerReplyException;
import org.apache.commons.net.ProtocolCommandListener;
import org.apache.commons.net.ProtocolCommandSupport;
import org.apache.commons.net.SocketClient;
/***
* The POP3 class is not meant to be used by itself and is provided
* only so that you may easily implement your own POP3 client if
* you so desire. If you have no need to perform your own implementation,
* you should use {@link org.apache.commons.net.pop3.POP3Client}.
* <p>
* Rather than list it separately for each method, we mention here that
* every method communicating with the server and throwing an IOException
* can also throw a
* {@link org.apache.commons.net.MalformedServerReplyException}
* , which is a subclass
* of IOException. A MalformedServerReplyException will be thrown when
* the reply received from the server deviates enough from the protocol
* specification that it cannot be interpreted in a useful manner despite
* attempts to be as lenient as possible.
* <p>
* <p>
* @author Daniel F. Savarese
* @see POP3Client
* @see org.apache.commons.net.MalformedServerReplyException
***/
public class POP3 extends SocketClient
{
/*** The default POP3 port. Set to 110 according to RFC 1288. ***/
public static final int DEFAULT_PORT = 110;
/***
* A constant representing the state where the client is not yet connected
* to a POP3 server.
***/
public static final int DISCONNECTED_STATE = -1;
/*** A constant representing the POP3 authorization state. ***/
public static final int AUTHORIZATION_STATE = 0;
/*** A constant representing the POP3 transaction state. ***/
public static final int TRANSACTION_STATE = 1;
/*** A constant representing the POP3 update state. ***/
public static final int UPDATE_STATE = 2;
static final String _OK = "+OK";
static final String _ERROR = "-ERR";
// We have to ensure that the protocol communication is in ASCII
// but we use ISO-8859-1 just in case 8-bit characters cross
// the wire.
private static final String __DEFAULT_ENCODING = "ISO-8859-1";
private int __popState;
private BufferedWriter __writer;
private StringBuffer __commandBuffer;
BufferedReader _reader;
int _replyCode;
String _lastReplyLine;
Vector _replyLines;
/***
* A ProtocolCommandSupport object used to manage the registering of
* ProtocolCommandListeners and te firing of ProtocolCommandEvents.
***/
protected ProtocolCommandSupport _commandSupport_;
/***
* The default POP3Client constructor. Initializes the state
* to <code>DISCONNECTED_STATE</code>.
***/
public POP3()
{
setDefaultPort(DEFAULT_PORT);
__commandBuffer = new StringBuffer();
__popState = DISCONNECTED_STATE;
_reader = null;
__writer = null;
_replyLines = new Vector();
_commandSupport_ = new ProtocolCommandSupport(this);
}
private void __getReply() throws IOException
{
String line;
_replyLines.setSize(0);
line = _reader.readLine();
if (line == null)
throw new EOFException("Connection closed without indication.");
if (line.startsWith(_OK))
_replyCode = POP3Reply.OK;
else if (line.startsWith(_ERROR))
_replyCode = POP3Reply.ERROR;
else
throw new
MalformedServerReplyException(
"Received invalid POP3 protocol response from server.");
_replyLines.addElement(line);
_lastReplyLine = line;
if (_commandSupport_.getListenerCount() > 0)
_commandSupport_.fireReplyReceived(_replyCode, getReplyString());
}
/***
* Performs connection initialization and sets state to
* <code> AUTHORIZATION_STATE </code>.
***/
protected void _connectAction_() throws IOException
{
super._connectAction_();
_reader =
new BufferedReader(new InputStreamReader(_input_,
__DEFAULT_ENCODING));
__writer =
new BufferedWriter(new OutputStreamWriter(_output_,
__DEFAULT_ENCODING));
__getReply();
setState(AUTHORIZATION_STATE);
}
/***
* Adds a ProtocolCommandListener. Delegates this task to
* {@link #_commandSupport_ _commandSupport_ }.
* <p>
* @param listener The ProtocolCommandListener to add.
***/
public void addProtocolCommandListener(ProtocolCommandListener listener)
{
_commandSupport_.addProtocolCommandListener(listener);
}
/***
* Removes a ProtocolCommandListener. Delegates this task to
* {@link #_commandSupport_ _commandSupport_ }.
* <p>
* @param listener The ProtocolCommandListener to remove.
***/
public void removeProtocolCommandistener(ProtocolCommandListener listener)
{
_commandSupport_.removeProtocolCommandListener(listener);
}
/***
* Sets POP3 client state. This must be one of the
* <code>_STATE</code> constants.
* <p>
* @param state The new state.
***/
public void setState(int state)
{
__popState = state;
}
/***
* Returns the current POP3 client state.
* <p>
* @return The current POP3 client state.
***/
public int getState()
{
return __popState;
}
/***
* Retrieves the additional lines of a multi-line server reply.
***/
public void getAdditionalReply() throws IOException
{
String line;
line = _reader.readLine();
while (line != null)
{
_replyLines.addElement(line);
if (line.equals("."))
break;
line = _reader.readLine();
}
}
/***
* Disconnects the client from the server, and sets the state to
* <code> DISCONNECTED_STATE </code>. The reply text information
* from the last issued command is voided to allow garbage collection
* of the memory used to store that information.
* <p>
* @exception IOException If there is an error in disconnecting.
***/
public void disconnect() throws IOException
{
super.disconnect();
_reader = null;
__writer = null;
_lastReplyLine = null;
_replyLines.setSize(0);
setState(DISCONNECTED_STATE);
}
/***
* Sends a command an arguments to the server and returns the reply code.
* <p>
* @param command The POP3 command to send.
* @param args The command arguments.
* @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
***/
public int sendCommand(String command, String args) throws IOException
{
String message;
__commandBuffer.setLength(0);
__commandBuffer.append(command);
if (args != null)
{
__commandBuffer.append(' ');
__commandBuffer.append(args);
}
__commandBuffer.append(SocketClient.NETASCII_EOL);
__writer.write(message = __commandBuffer.toString());
__writer.flush();
if (_commandSupport_.getListenerCount() > 0)
_commandSupport_.fireCommandSent(command, message);
__getReply();
return _replyCode;
}
/***
* Sends a command with no arguments to the server and returns the
* reply code.
* <p>
* @param command The POP3 command to send.
* @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
***/
public int sendCommand(String command) throws IOException
{
return sendCommand(command, null);
}
/***
* Sends a command an arguments to the server and returns the reply code.
* <p>
* @param command The POP3 command to send
* (one of the POP3Command constants).
* @param args The command arguments.
* @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
***/
public int sendCommand(int command, String args) throws IOException
{
return sendCommand(POP3Command._commands[command], args);
}
/***
* Sends a command with no arguments to the server and returns the
* reply code.
* <p>
* @param command The POP3 command to send
* (one of the POP3Command constants).
* @return The server reply code (either POP3Reply.OK or POP3Reply.ERROR).
***/
public int sendCommand(int command) throws IOException
{
return sendCommand(POP3Command._commands[command], null);
}
/***
* Returns an array of lines received as a reply to the last command
* sent to the server. The lines have end of lines truncated. If
* the reply is a single line, but its format ndicates it should be
* a multiline reply, then you must call
* {@link #getAdditionalReply getAdditionalReply() } to
* fetch the rest of the reply, and then call <code>getReplyStrings</code>
* again. You only have to worry about this if you are implementing
* your own client using the {@link #sendCommand sendCommand } methods.
* <p>
* @return The last server response.
***/
public String[] getReplyStrings()
{
String[] lines;
lines = new String[_replyLines.size()];
_replyLines.copyInto(lines);
return lines;
}
/***
* Returns the reply to the last command sent to the server.
* The value is a single string containing all the reply lines including
* newlines. If the reply is a single line, but its format ndicates it
* should be a multiline reply, then you must call
* {@link #getAdditionalReply getAdditionalReply() } to
* fetch the rest of the reply, and then call <code>getReplyString</code>
* again. You only have to worry about this if you are implementing
* your own client using the {@link #sendCommand sendCommand } methods.
* <p>
* @return The last server response.
***/
public String getReplyString()
{
Enumeration en;
StringBuffer buffer = new StringBuffer(256);
en = _replyLines.elements();
while (en.hasMoreElements())
{
buffer.append((String)en.nextElement());
buffer.append(SocketClient.NETASCII_EOL);
}
return buffer.toString();
}
}
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