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:

  • Field Details

  • 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()
      Provide command support to super-class
      Overrides:
      getCommandSupport in class SocketClient
      Returns:
      the CommandSupport instance, may be null

    • getReply

      public int getReply() throws IOException
      Fetches 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()
      Returns 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()
      Returns 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.