panda.net.pop3.POP3 Maven / Gradle / Ivy
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package panda.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 panda.net.MalformedServerReplyException;
import panda.net.ProtocolCommandSupport;
import panda.net.SocketClient;
import panda.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 panda.net.pop3.POP3Client}.
*
* 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 panda.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.
*
* @see POP3Client
* @see panda.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 _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 DISCONNECTED_STATE.
***/
public POP3() {
setDefaultPort(DEFAULT_PORT);
__popState = DISCONNECTED_STATE;
_reader = null;
_writer = null;
_replyLines = new ArrayList();
_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 AUTHORIZATION_STATE .
***/
@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 _STATE constants.
*/
public void setState(int state) {
__popState = state;
}
/***
* Returns the current POP3 client state.
*
* @return The current POP3 client state.
***/
public int getState() {
return __popState;
}
/***
* Retrieves the additional lines of a multi-line server reply.
*
* @throws IOException on error
***/
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
* DISCONNECTED_STATE . The reply text information from the last issued command is
* voided to allow garbage collection of the memory used to store that information.
*
* @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.
*
* @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).
* @throws IOException on error
***/
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.
*
* @param command The POP3 command to send.
* @return The server reply code (either POP3Reply.OK, POP3Reply.ERROR or POP3Reply.OK_INT).
* @throws IOException on 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.
*
* @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).
* @throws IOException on 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.
*
* @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).
* @throws IOException on 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
* getReplyStrings again. You only have to worry about this if you are implementing
* your own client using the {@link #sendCommand sendCommand } methods.
*
* @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 getReplyString again. You only have to worry about this if you are
* implementing your own client using the {@link #sendCommand sendCommand } methods.
*
* @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(panda.net.ProtocolCommandListener listener) {
removeProtocolCommandListener(listener);
}
/**
* Provide command support to super-class
*/
@Override
protected ProtocolCommandSupport getCommandSupport() {
return _commandSupport_;
}
}