/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.util.ArrayList;
import java.util.List;
import org.apache.commons.net.MalformedServerReplyException;
import org.apache.commons.net.ProtocolCommandSupport;
import org.apache.commons.net.SocketClient;
import org.apache.commons.net.io.CRLFLineReader;
/***
* 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>
* @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";
// The reply indicating intermediate response to a command.
static final String _OK_INT = "+ ";
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.
static final String _DEFAULT_ENCODING = "ISO-8859-1";
private int __popState;
BufferedWriter _writer;
BufferedReader _reader;
int _replyCode;
String _lastReplyLine;
List<String> _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);
__popState = DISCONNECTED_STATE;
_reader = null;
_writer = null;
_replyLines = new ArrayList<String>();
_commandSupport_ = new ProtocolCommandSupport(this);
}
private void __getReply() throws IOException
{
String line;
_replyLines.clear();
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 if (line.startsWith(_OK_INT)) {
_replyCode = POP3Reply.OK_INT;
} else {
throw new
MalformedServerReplyException(
"Received invalid POP3 protocol response from server." + line);
}
_replyLines.add(line);
_lastReplyLine = line;
fireReplyReceived(_replyCode, getReplyString());
}
/***
* Performs connection initialization and sets state to
* <code> AUTHORIZATION_STATE </code>.
***/
@Override
protected void _connectAction_() throws IOException
{
super._connectAction_();
_reader =
new CRLFLineReader(new InputStreamReader(_input_,
_DEFAULT_ENCODING));
_writer =
new BufferedWriter(new OutputStreamWriter(_output_,
_DEFAULT_ENCODING));
__getReply();
setState(AUTHORIZATION_STATE);
}
/**
* Set the internal POP3 state.
* @param state the new state. This must be one of the <code>_STATE</code> constants.
*/
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.add(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.
***/
@Override
public void disconnect() throws IOException
{
super.disconnect();
_reader = null;
_writer = null;
_lastReplyLine = null;
_replyLines.clear();
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, POP3Reply.ERROR or POP3Reply.OK_INT).
***/
public int sendCommand(String command, String args) throws IOException
{
if (_writer == null) {
throw new IllegalStateException("Socket is not connected");
}
StringBuilder __commandBuffer = new StringBuilder();
__commandBuffer.append(command);
if (args != null)
{
__commandBuffer.append(' ');
__commandBuffer.append(args);
}
__commandBuffer.append(SocketClient.NETASCII_EOL);
String message = __commandBuffer.toString();
_writer.write(message);
_writer.flush();
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, POP3Reply.ERROR or POP3Reply.OK_INT).
***/
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, POP3Reply.ERROR or POP3Reply.OK_INT).
***/
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, POP3Reply.ERROR or POP3Reply.OK_INT).
***/
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()
{
return _replyLines.toArray(new String[_replyLines.size()]);
}
/***
* 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()
{
StringBuilder buffer = new StringBuilder(256);
for (String entry : _replyLines)
{
buffer.append(entry);
buffer.append(SocketClient.NETASCII_EOL);
}
return buffer.toString();
}
/**
* Removes a ProtocolCommandListener.
*
* Delegates this incorrectly named method - removeProtocolCommandistener (note the missing "L")- to
* the correct method {@link SocketClient#removeProtocolCommandListener}
* @param listener The ProtocolCommandListener to remove
*/
public void removeProtocolCommandistener(org.apache.commons.net.ProtocolCommandListener listener){
removeProtocolCommandListener(listener);
}
/**
* Provide command support to super-class
*/
@Override
protected ProtocolCommandSupport getCommandSupport() {
return _commandSupport_;
}
}