Package org.apache.commons.net.nntp

# Class NNTP

java.lang.Object
org.apache.commons.net.SocketClient
org.apache.commons.net.nntp.NNTP

Direct Known Subclasses:
  `NNTPClient`

public class NNTP extends SocketClient
The NNTP class is not meant to be used by itself and is provided only so that you may easily implement your own NNTP client if you so desire. If you have no need to perform your own implementation, you should use `NNTPClient`. The NNTP class is made public to provide access to various NNTP constants and to make it easier for adventurous programmers (or those with special needs) to interact with the NNTP protocol and implement their own clients. A set of methods with names corresponding to the NNTP command names are provided to facilitate this interaction.

You should keep in mind that the NNTP server may choose to prematurely close a connection if the client has been idle for longer than a given time period or if the server is being shutdown by the operator or some other reason. The NNTP class will detect a premature NNTP server connection closing when it receives a `NNTPReply.SERVICE_DISCONTINUED` response to a command. When that occurs, the NNTP class method encountering that reply will throw an `NNTPConnectionClosedException` . `NNTPConectionClosedException` is a subclass of `IOException` and therefore need not be caught separately, but if you are going to catch it separately, its catch block must appear before the more general `IOException` catch block. When you encounter an `NNTPConnectionClosedException` , you must disconnect the connection with `disconnect()` to properly clean up the system resources used by NNTP. Before disconnecting, you may check the last reply code and text with `getReplyCode` and `getReplyString`.

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 `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 Also:
  - `NNTPClient`
  - `NNTPConnectionClosedException`
  - `MalformedServerReplyException`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected ProtocolCommandSupport`
  `_commandSupport_`
  A ProtocolCommandSupport object used to manage the registering of ProtocolCommandListeners and te firing of ProtocolCommandEvents.
  `protected BufferedReader`
  `_reader_`
  Wraps `SocketClient._input_` to communicate with server.
  `protected BufferedWriter`
  `_writer_`
  Wraps `SocketClient._output_` to communicate with server.
  `static final int`
  `DEFAULT_PORT`
  The default NNTP port.

  ### Fields inherited from class org.apache.commons.net.SocketClient

  `_defaultPort_, _hostname_, _input_, _output_, _serverSocketFactory_, _socket_, _socketFactory_, _timeout_, connectTimeout, NETASCII_EOL, remoteInetSocketAddress`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `NNTP()`
  The default NNTP constructor.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected void`
  `_connectAction_()`
  Initiates control connections and gets initial reply, determining if the client is allowed to post to the server.
  `int`
  `article()`
  A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
  `int`
  `article(int a)`
  Deprecated.
  - for API compatibility only - DO NOT USE
  `int`
  `article(long articleNumber)`
  A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
  `int`
  `article(String messageId)`
  A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
  `int`
  `authinfoPass(String password)`
  A convenience method to send the AUTHINFO PASS command to the server, receive the reply, and return the reply code.
  `int`
  `authinfoUser(String user)`
  A convenience method to send the AUTHINFO USER command to the server, receive the reply, and return the reply code.
  `int`
  `body()`
  A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
  `int`
  `body(int a)`
  Deprecated.
  - for API compatibility only - DO NOT USE
  `int`
  `body(long articleNumber)`
  A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
  `int`
  `body(String messageId)`
  A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
  `void`
  `disconnect()`
  Closes the connection to the NNTP server and sets to null some internal data so that the memory may be reclaimed by the garbage collector.
  `protected ProtocolCommandSupport`
  `getCommandSupport()`
  Gets the command support.
  `int`
  `getReply()`
  Gets a reply from the NNTP server and returns the integer reply code.
  `int`
  `getReplyCode()`
  Gets the integer value of the reply code of the last NNTP reply.
  `String`
  `getReplyString()`
  Gets the entire text of the last NNTP server response exactly as it was received, not including the end of line marker.
  `int`
  `group(String newsgroup)`
  A convenience method to send the NNTP GROUP command to the server, receive the reply, and return the reply code.
  `int`
  `head()`
  A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
  `int`
  `head(int a)`
  Deprecated.
  - for API compatibility only - DO NOT USE
  `int`
  `head(long articleNumber)`
  A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
  `int`
  `head(String messageId)`
  A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
  `int`
  `help()`
  A convenience method to send the NNTP HELP command to the server, receive the reply, and return the reply code.
  `int`
  `ihave(String messageId)`
  A convenience method to send the NNTP IHAVE command to the server, receive the reply, and return the reply code.
  `boolean`
  `isAllowedToPost()`
  Indicates whether or not the client is allowed to post articles to the server it is currently connected to.
  `int`
  `last()`
  A convenience method to send the NNTP LAST command to the server, receive the reply, and return the reply code.
  `int`
  `list()`
  A convenience method to send the NNTP LIST command to the server, receive the reply, and return the reply code.
  `int`
  `listActive(String wildmat)`
  A convenience wrapper for the extended LIST command that takes an argument, allowing us to selectively list multiple groups.
  `int`
  `newgroups(String date, String time, boolean GMT, String distributions)`
  A convenience method to send the "NEWGROUPS" command to the server, receive the reply, and return the reply code.
  `int`
  `newnews(String newsgroups, String date, String time, boolean GMT, String distributions)`
  A convenience method to send the "NEWNEWS" command to the server, receive the reply, and return the reply code.
  `int`
  `next()`
  A convenience method to send the NNTP NEXT command to the server, receive the reply, and return the reply code.
  `int`
  `post()`
  A convenience method to send the NNTP POST command to the server, receive the reply, and return the reply code.
  `int`
  `quit()`
  A convenience method to send the NNTP QUIT command to the server, receive the reply, and return the reply code.
  `int`
  `sendCommand(int command)`
  Sends an NNTP command with no arguments to the server, waits for a reply and returns the numerical response code.
  `int`
  `sendCommand(int command, String args)`
  Sends an NNTP command to the server, waits for a reply and returns the numerical response code.
  `int`
  `sendCommand(String command)`
  Sends an NNTP command with no arguments to the server, waits for a reply and returns the numerical response code.
  `int`
  `sendCommand(String command, String args)`
  Sends an NNTP command to the server, waits for a reply and returns the numerical response code.
  `int`
  `stat()`
  A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
  `int`
  `stat(int a)`
  Deprecated.
  - for API compatibility only - DO NOT USE
  `int`
  `stat(long articleNumber)`
  A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
  `int`
  `stat(String messageId)`
  A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
  `int`
  `xhdr(String header, String selectedArticles)`
  A convenience method to send the NNTP XHDR command to the server, receive the reply, and return the reply code.
  `int`
  `xover(String selectedArticles)`
  A convenience method to send the NNTP XOVER command to the server, receive the reply, and return the reply code.

  ### Methods inherited from class org.apache.commons.net.SocketClient

  `addProtocolCommandListener, applySocketAttributes, checkOpenOutputStream, connect, connect, connect, connect, connect, connect, createCommandSupport, fireCommandSent, fireReplyReceived, getCharset, getCharsetName, getConnectTimeout, getDefaultPort, getDefaultTimeout, getHostAddress, getHostAddress, getKeepAlive, getLocalAddress, getLocalPort, getProxy, getReceiveBufferSize, getRemoteAddress, getRemoteInetSocketAddress, getRemotePort, getSendBufferSize, getServerSocketFactory, getSoLinger, getSoTimeout, getTcpNoDelay, isAvailable, isConnected, removeProtocolCommandListener, setCharset, setConnectTimeout, setDefaultPort, setDefaultTimeout, setKeepAlive, setProxy, setReceiveBufferSize, setSendBufferSize, setServerSocketFactory, setSocketFactory, setSoLinger, setSoTimeout, setTcpNoDelay, verifyRemote`

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### DEFAULT_PORT

    public static final int DEFAULT_PORT
    The default NNTP port. Its value is 119 according to RFC 977.
    See Also:
      - Constant Field Values

  - ### _reader_

    protected BufferedReader _reader_
    Wraps `SocketClient._input_` to communicate with server. Initialized by `_connectAction_()`. All server reads should be done through this variable.

  - ### _writer_

    protected BufferedWriter _writer_
    Wraps `SocketClient._output_` to communicate with server. Initialized by `_connectAction_()`. All server reads should be done through this variable.

  - ### _commandSupport_

    protected ProtocolCommandSupport _commandSupport_
    A ProtocolCommandSupport object used to manage the registering of ProtocolCommandListeners and te firing of ProtocolCommandEvents.

- ## Constructor Details

  - ### NNTP

    public NNTP()
    The default NNTP constructor. Sets the default port to `DEFAULT_PORT` and initializes internal data structures for saving NNTP reply information.

- ## Method Details

  - ### _connectAction_

    protected void _connectAction_() throws IOException
    Initiates control connections and gets initial reply, determining if the client is allowed to post to the server. Initializes `_reader_` and `_writer_` to wrap `SocketClient._input_` and `SocketClient._output_`.
    Overrides:
      `_connectAction_` in class `SocketClient`
    Throws:
      `IOException` - (SocketException) if a problem occurs with the socket

  - ### article

    public int article() throws IOException
    A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### article

    @Deprecated public int article(int a) throws IOException
    Deprecated.
    - for API compatibility only - DO NOT USE
    Parameters:
      `a` - article number
    Returns:
      number
    Throws:
      `IOException` - on error

  - ### article

    public int article(long articleNumber) throws IOException
    A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `articleNumber` - The number of the article to request from the currently selected newsgroup.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### article

    public int article(String messageId) throws IOException
    A convenience method to send the NNTP ARTICLE command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `messageId` - The message identifier of the requested article, including the encapsulating < and > characters.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### authinfoPass

    public int authinfoPass(String password) throws IOException
    A convenience method to send the AUTHINFO PASS command to the server, receive the reply, and return the reply code. If this step is required, it should immediately follow the AUTHINFO USER command (See RFC 2980)
    Parameters:
      `password` - a valid password.
    Returns:
      The reply code received from the server. The server should return a 281 or 502 for this command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### authinfoUser

    public int authinfoUser(String user) throws IOException
    A convenience method to send the AUTHINFO USER command to the server, receive the reply, and return the reply code. (See RFC 2980)
    Parameters:
      `user` - A valid user name.
    Returns:
      The reply code received from the server. The server should return a 381 or 281 for this command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### body

    public int body() throws IOException
    A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### body

    @Deprecated public int body(int a) throws IOException
    Deprecated.
    - for API compatibility only - DO NOT USE
    Parameters:
      `a` - article number
    Returns:
      number
    Throws:
      `IOException` - on error

  - ### body

    public int body(long articleNumber) throws IOException
    A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `articleNumber` - The number of the article to request from the currently selected newsgroup.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### body

    public int body(String messageId) throws IOException
    A convenience method to send the NNTP BODY command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `messageId` - The message identifier of the requested article, including the encapsulating < and > characters.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### disconnect

    public void disconnect() throws IOException
    Closes the connection to the NNTP server and sets to null some internal data so that the memory may be reclaimed by the garbage collector. The reply text and code information from the last command is voided so that the memory it used may be reclaimed.
    Overrides:
      `disconnect` in class `SocketClient`
    Throws:
      `IOException` - If an error occurs while disconnecting.

  - ### getCommandSupport

    protected ProtocolCommandSupport getCommandSupport()
    Gets the command support.
    Overrides:
      `getCommandSupport` in class `SocketClient`
    Returns:
      the CommandSupport instance, may be `null`

  - ### getReply

    public int getReply() throws IOException
    Gets a reply from the NNTP server and returns the integer reply code. After calling this method, the actual reply text can be accessed from `getReplyString`. Only use this method if you are implementing your own NNTP client or if you need to fetch a secondary response from the NNTP server.
    Returns:
      The integer value of the reply code of the fetched NNTP reply. in response to the command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while receiving the server reply.

  - ### getReplyCode

    public int getReplyCode()
    Gets the integer value of the reply code of the last NNTP reply. You will usually only use this method after you connect to the NNTP server to check that the connection was successful since `connect` is of type void.
    Returns:
      The integer value of the reply code of the last NNTP reply.

  - ### getReplyString

    public String getReplyString()
    Gets the entire text of the last NNTP server response exactly as it was received, not including the end of line marker.
    Returns:
      The entire text from the last NNTP response as a String.

  - ### group

    public int group(String newsgroup) throws IOException
    A convenience method to send the NNTP GROUP command to the server, receive the reply, and return the reply code.
    Parameters:
      `newsgroup` - The name of the newsgroup to select.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### head

    public int head() throws IOException
    A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### head

    @Deprecated public int head(int a) throws IOException
    Deprecated.
    - for API compatibility only - DO NOT USE
    Parameters:
      `a` - article number
    Returns:
      number
    Throws:
      `IOException` - on error

  - ### head

    public int head(long articleNumber) throws IOException
    A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `articleNumber` - The number of the article to request from the currently selected newsgroup.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### head

    public int head(String messageId) throws IOException
    A convenience method to send the NNTP HEAD command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `messageId` - The message identifier of the requested article, including the encapsulating < and > characters.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### help

    public int help() throws IOException
    A convenience method to send the NNTP HELP command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### ihave

    public int ihave(String messageId) throws IOException
    A convenience method to send the NNTP IHAVE command to the server, receive the reply, and return the reply code.
    Parameters:
      `messageId` - The article identifier, including the encapsulating < and > characters.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### isAllowedToPost

    public boolean isAllowedToPost()
    Indicates whether or not the client is allowed to post articles to the server it is currently connected to.
    Returns:
      True if the client can post articles to the server, false otherwise.

  - ### last

    public int last() throws IOException
    A convenience method to send the NNTP LAST command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### list

    public int list() throws IOException
    A convenience method to send the NNTP LIST command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### listActive

    public int listActive(String wildmat) throws IOException
    A convenience wrapper for the extended LIST command that takes an argument, allowing us to selectively list multiple groups.
    Parameters:
      `wildmat` - A wildmat (pseudo-regex) pattern. See RFC 2980 for details.
    Returns:
      the reply code received from the server.
    Throws:
      `IOException` - if the command fails

  - ### newgroups

    public int newgroups(String date, String time, boolean GMT, String distributions) throws IOException
    A convenience method to send the "NEWGROUPS" command to the server, receive the reply, and return the reply code.
    Parameters:
      `date` - The date after which to check for new groups. Date format is YYMMDD
      `time` - The time after which to check for new groups. Time format is HHMMSS using a 24-hour clock.
      `GMT` - True if the time is in GMT, false if local server time.
      `distributions` - Comma-separated distribution list to check for new groups. Set to null if no distributions.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### newnews

    public int newnews(String newsgroups, String date, String time, boolean GMT, String distributions) throws IOException
    A convenience method to send the "NEWNEWS" command to the server, receive the reply, and return the reply code.
    Parameters:
      `newsgroups` - A comma-separated list of newsgroups to check for new news.
      `date` - The date after which to check for new news. Date format is YYMMDD
      `time` - The time after which to check for new news. Time format is HHMMSS using a 24-hour clock.
      `GMT` - True if the time is in GMT, false if local server time.
      `distributions` - Comma-separated distribution list to check for new news. Set to null if no distributions.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### next

    public int next() throws IOException
    A convenience method to send the NNTP NEXT command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### post

    public int post() throws IOException
    A convenience method to send the NNTP POST command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### quit

    public int quit() throws IOException
    A convenience method to send the NNTP QUIT command to the server, receive the reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### sendCommand

    public int sendCommand(int command) throws IOException
    Sends an NNTP command with no arguments to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the actual reply text can be accessed by calling `getReplyString`.
    Parameters:
      `command` - The NNTPCommand constant corresponding to the NNTP command to send.
    Returns:
      The integer value of the NNTP reply code returned by the server in response to the command. in response to the command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### sendCommand

    public int sendCommand(int command, String args) throws IOException
    Sends an NNTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the actual reply text can be accessed by calling `getReplyString`.
    Parameters:
      `command` - The NNTPCommand constant corresponding to the NNTP command to send.
      `args` - The arguments to the NNTP command. If this parameter is set to null, then the command is sent with no argument.
    Returns:
      The integer value of the NNTP reply code returned by the server in response to the command. in response to the command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### sendCommand

    public int sendCommand(String command) throws IOException
    Sends an NNTP command with no arguments to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the actual reply text can be accessed by calling `getReplyString`.
    Parameters:
      `command` - The text representation of the NNTP command to send.
    Returns:
      The integer value of the NNTP reply code returned by the server in response to the command. in response to the command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### sendCommand

    public int sendCommand(String command, String args) throws IOException
    Sends an NNTP command to the server, waits for a reply and returns the numerical response code. After invocation, for more detailed information, the actual reply text can be accessed by calling `getReplyString`.
    Parameters:
      `command` - The text representation of the NNTP command to send.
      `args` - The arguments to the NNTP command. If this parameter is set to null, then the command is sent with no argument.
    Returns:
      The integer value of the NNTP reply code returned by the server in response to the command.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### stat

    public int stat() throws IOException
    A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### stat

    @Deprecated public int stat(int a) throws IOException
    Deprecated.
    - for API compatibility only - DO NOT USE
    Parameters:
      `a` - article number
    Returns:
      number
    Throws:
      `IOException` - on error

  - ### stat

    public int stat(long articleNumber) throws IOException
    A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `articleNumber` - The number of the article to request from the currently selected newsgroup.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### stat

    public int stat(String messageId) throws IOException
    A convenience method to send the NNTP STAT command to the server, receive the initial reply, and return the reply code.
    Parameters:
      `messageId` - The message identifier of the requested article, including the encapsulating < and > characters.
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### xhdr

    public int xhdr(String header, String selectedArticles) throws IOException
    A convenience method to send the NNTP XHDR command to the server, receive the reply, and return the reply code.
    Parameters:
      `header` - a String naming a header line (e.g., "subject"). See RFC-1036 for a list of valid header lines.
      `selectedArticles` - a String representation of the range of article headers required. This may be an article number, or a range of article numbers in the form "XXXX-YYYY", where XXXX and YYYY are valid article numbers in the current group. It also may be of the form "XXX-", meaning "return XXX and all following articles" In this revision, the last format is not possible (yet).
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.

  - ### xover

    public int xover(String selectedArticles) throws IOException
    A convenience method to send the NNTP XOVER command to the server, receive the reply, and return the reply code.
    Parameters:
      `selectedArticles` - a String representation of the range of article headers required. This may be an article number, or a range of article numbers in the form "XXXX-YYYY", where XXXX and YYYY are valid article numbers in the current group. It also may be of the form "XXX-", meaning "return XXX and all following articles" In this revision, the last format is not possible (yet).
    Returns:
      The reply code received from the server.
    Throws:
      `NNTPConnectionClosedException` - If the NNTP server prematurely closes the connection as a result of the client being idle or some other reason causing the server to send NNTP reply code 400. This exception may be caught either as an IOException or independently as itself.
      `IOException` - If an I/O error occurs while either sending the command or receiving the server reply.