articleId field of the ArticlePointer cannot always be trusted because some NNTP servers do not correctly follow the RFC 977 reply format. A DotTerminatedMessageReader is returned from which the article can be read. If the article does not exist, null is returned.
You must not issue any commands to the NNTP server (i.e., call any other methods) until you finish reading the message from the returned Reader instance. The NNTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned Reader actually reads directly from the NNTP connection. After the end of message has been reached, new commands can be executed and their replies read. If you do not follow these requirements, your program will not work properly.
@param articleId The unique article identifier of the article whoseheader is being retrieved. If this parameter is null, the header of the currently selected article is retrieved. @param pointer A parameter through which to return the article'snumber and unique id. The articleId field cannot always be trusted because of server deviations from RFC 977 reply formats. You may set this parameter to null if you do not desire to retrieve the returned article information. @return A DotTerminatedMessageReader instance from which the articleheader can be read. null if the article does not exist. @exception 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. @exception IOException If an I/O error occurs while either sending acommand to the server or receiving a reply from the server.
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