Examples of org.apache.commons.net.nntp.NNTPClient

org.apache.commons.net.nntp.NNTPClient
NNTPClient encapsulates all the functionality necessary to post and retrieve articles from an NNTP server. As with all classes derived from SocketClient , you must first connect to the server with connect before doing anything, and finally disconnect() after you're completely finished interacting with the server. Remember that the isAllowedToPost() method is defined in NNTP .
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.

@author Daniel F. Savarese @see NNTP @see NNTPConnectionClosedException @see org.apache.commons.net.MalformedServerReplyException


    /* Retrieve last article pointer */
    Integer lastArticleId = getLastArticleId(properties);


    /* Create a new HttpClient */
    NNTPClient client = new NNTPClient();


    try {


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Connect to Server */
      if (link.getPort() != -1)
        client.connect(link.getHost(), link.getPort());
      else
        client.connect(link.getHost());


      /* Set Timeout */
      setTimeout(client, properties);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Authentication if provided */
      setupAuthentication(link, client);


      /* Check Authentication Required */
      checkAuthenticationRequired(client);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Enable Reader Mode */
      client.sendCommand(MODE_READER);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Select Newsgroup */
      String newsgroup = link.getPath().replace("/", "");
      NewsgroupInfo groupInfo = new NewsgroupInfo();
      boolean selected = client.selectNewsgroup(newsgroup, groupInfo);


      /* Check Authentication Required */
      checkAuthenticationRequired(client);


      /* Check Newsgroup Selected */
      if (!selected)
        throwConnectionException("Unable to select Newsgroup", client);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* First reload: Retrieve an initial amount of News */
      if (lastArticleId == null) {


        /* Set Article Pointer to last Article */
        int status = client.stat(groupInfo.getLastArticle());
        if (status != STATUS_ARTICLE_POINTER_OK)
          throwConnectionException("Unable to retrieve any News", client);


        /* Retrieve initial news */
        for (int i = 0; i < INITIAL_NEWS && !monitor.isCanceled(); i++) {
          createNews(client.retrieveArticle(), feed, monitor);


          /* Goto previous news if provided */
          int result = client.last();
          if (result != STATUS_ARTICLE_POINTER_OK)
            break;
        }
      }


      /* Subsequent reload: Set pointer to last retrieved News */
      else {


        /* Set Article Pointer to last retrieved News */
        int status = client.stat(lastArticleId);
        if (status != STATUS_ARTICLE_POINTER_OK)
          throwConnectionException("Unable to retrieve any News", client);


        /* Retrieve all the following News */
        while (client.next() == STATUS_ARTICLE_POINTER_OK && !monitor.isCanceled())
          createNews(client.retrieveArticle(), feed, monitor);
      }


      /* Remember last article's ID */
      lastArticleId = groupInfo.getLastArticle();
    }


    /* Wrap Exceptions */
    catch (IOException e) {
      throw new ConnectionException(Activator.getDefault().createErrorStatus(e.getMessage(), e));
    }


    /* Disconnect */
    finally {
      try {
        if (client.isConnected())
          client.disconnect();
      } catch (IOException e) {
        throw new ConnectionException(Activator.getDefault().createErrorStatus(e.getMessage(), e));
      }
    }

View Full Code Here

    }


    NNTPClient client;
  
    public ExtendedNNTPOps() {
        client = new NNTPClient();
        client.addProtocolCommandListener(new PrintCommandListener(
                                          new PrintWriter(System.out)));
    }

View Full Code Here

        String from, subject, newsgroup, filename, server, organization;
        String references;
        BufferedReader stdin;
        FileReader fileReader = null;
        SimpleNNTPHeader header;
        NNTPClient client;


        if (args.length < 1)
        {
            System.err.println("Usage: post newsserver");
            System.exit(1);
        }


        server = args[0];


        stdin = new BufferedReader(new InputStreamReader(System.in));


        try
        {
            System.out.print("From: ");
            System.out.flush();


            from = stdin.readLine();


            System.out.print("Subject: ");
            System.out.flush();


            subject = stdin.readLine();


            header = new SimpleNNTPHeader(from, subject);


            System.out.print("Newsgroup: ");
            System.out.flush();


            newsgroup = stdin.readLine();
            header.addNewsgroup(newsgroup);


            while (true)
            {
                System.out.print("Additional Newsgroup <Hit enter to end>: ");
                System.out.flush();


                // Of course you don't want to do this because readLine() may be null
                newsgroup = stdin.readLine().trim();


                if (newsgroup.length() == 0)
                    break;


                header.addNewsgroup(newsgroup);
            }


            System.out.print("Organization: ");
            System.out.flush();


            organization = stdin.readLine();


            System.out.print("References: ");
            System.out.flush();


            references = stdin.readLine();


            if (organization != null && organization.length() > 0)
                header.addHeaderField("Organization", organization);


            if (references != null && organization.length() > 0)
                header.addHeaderField("References", references);


            header.addHeaderField("X-Newsreader", "NetComponents");


            System.out.print("Filename: ");
            System.out.flush();


            filename = stdin.readLine();


            try
            {
                fileReader = new FileReader(filename);
            }
            catch (FileNotFoundException e)
            {
                System.err.println("File not found. " + e.getMessage());
                System.exit(1);
            }


            client = new NNTPClient();
            client.addProtocolCommandListener(new PrintCommandListener(
                                                  new PrintWriter(System.out)));


            client.connect(server);


            if (!NNTPReply.isPositiveCompletion(client.getReplyCode()))
            {
                client.disconnect();
                System.err.println("NNTP server refused connection.");
                System.exit(1);
            }


            if (client.isAllowedToPost())
            {
                Writer writer = client.postArticle();


                if (writer != null)
                {
                    writer.write(header.toString());
                    Util.copyReader(fileReader, writer);
                    writer.close();
                    client.completePendingCommand();
                }
            }


            fileReader.close();


            client.logout();


            client.disconnect();
        }
        catch (IOException e)
        {
            e.printStackTrace();
            System.exit(1);

View Full Code Here

        
        String hostname = args[0];
        String user = args[1];
        String password = args[2];
        
        NNTPClient client = new NNTPClient();
        client.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
        client.connect(hostname);
        
        if(!client.authenticate(user, password)) {
            System.out.println("Authentication failed for user " + user + "!");
            System.exit(1);
        }
        
        NewsgroupInfo group = new NewsgroupInfo();
        client.selectNewsgroup("comp.lang.lisp", group);
        
        int lowArticleNumber = group.getFirstArticle();
        int highArticleNumber = lowArticleNumber + 100;
        
        System.out.println("Retrieving articles between [" + lowArticleNumber + "] and [" + highArticleNumber + "]");

View Full Code Here

public final class newsgroups
{


    public final static void main(String[] args)
    {
        NNTPClient client;
        NewsgroupInfo[] list;


        if (args.length < 1)
        {
            System.err.println("Usage: newsgroups newsserver");
            System.exit(1);
        }


        client = new NNTPClient();


        try
        {
            client.connect(args[0]);


            list = client.listNewsgroups();


            if (list != null)
            {
                for (int i = 0; i < list.length; i++)
                    System.out.println(list[i].getNewsgroup());
            }
            else
            {
                System.err.println("LIST command failed.");
                System.err.println("Server reply: " + client.getReplyString());
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            try
            {
                if (client.isConnected())
                    client.disconnect();
            }
            catch (IOException e)
            {
                System.err.println("Error disconnecting from server.");
                e.printStackTrace();

View Full Code Here


    
    NNTPClient client;


    public ExtendedNNTPOps() {
        client = new NNTPClient();
        client.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
    }

View Full Code Here


    /* Retrieve last article pointer (If-None-Match header value) */
    Integer lastArticleId = getLastArticleId(properties);


    /* Create a new HttpClient */
    NNTPClient client = new NNTPClient();


    try {


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Connect to Server */
      if (link.getPort() != -1)
        client.connect(link.getHost(), link.getPort());
      else
        client.connect(link.getHost());


      /* Set Timeout */
      setTimeout(client, properties);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Authentication if provided */
      setupAuthentication(link, client);


      /* Check Authentication Required */
      checkAuthenticationRequired(client, link);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Enable Reader Mode */
      client.sendCommand(MODE_READER);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      /* Select Newsgroup */
      String newsgroup = link.getPath().replace("/", ""); //$NON-NLS-1$ //$NON-NLS-2$
      NewsgroupInfo groupInfo = new NewsgroupInfo();
      boolean selected = client.selectNewsgroup(newsgroup, groupInfo);


      /* Check Authentication Required */
      checkAuthenticationRequired(client, link);


      /* Check Newsgroup Selected */
      if (!selected)
        throwConnectionException(Messages.NewsGroupHandler_ERROR_SELECT_NEWSGROUP, client);


      /* Support early cancellation */
      if (monitor.isCanceled())
        return null;


      boolean downloadWithoutPointer = (lastArticleId == null); //Last article servers as pointer


      /* Subsequent reload: Set pointer to last retrieved News and go from there */
      if (lastArticleId != null) {


        /* Set Article Pointer to last retrieved News */
        int status = client.stat(lastArticleId);
        if (status == NO_SUCH_ARTICLE_ERROR)
          downloadWithoutPointer = true; //This can happen if the last article id was not found, grab the latest news then
        else if (status != STATUS_ARTICLE_POINTER_OK)
          throwConnectionException(Messages.NewsGroupHandler_ERROR_RETRIEVE_NEWS, client);


        /* Retrieve all the following News */
        if (!downloadWithoutPointer) {
          while (client.next() == STATUS_ARTICLE_POINTER_OK && !monitor.isCanceled())
            createNews(client.retrieveArticle(), feed, monitor);
        }
      }


      /* Retrieve the last 50 News of the group */
      if (downloadWithoutPointer) {


        /* Set Article Pointer to last Article */
        int status = client.stat(groupInfo.getLastArticle());
        if (status != STATUS_ARTICLE_POINTER_OK)
          throwConnectionException(Messages.NewsGroupHandler_ERROR_RETRIEVE_NEWS, client);


        /* Retrieve initial news */
        for (int i = 0; i < INITIAL_NEWS && !monitor.isCanceled(); i++) {
          createNews(client.retrieveArticle(), feed, monitor);


          /* Goto previous news if provided */
          int result = client.last();
          if (result != STATUS_ARTICLE_POINTER_OK)
            break;
        }
      }


      /* Remember last article's ID */
      lastArticleId = groupInfo.getLastArticle();
    }


    /* Wrap Exceptions */
    catch (IOException e) {
      throw new ConnectionException(Activator.createErrorStatus(e.getMessage(), e));
    }


    /* Disconnect */
    finally {
      try {
        if (client.isConnected())
          client.disconnect();
      } catch (IOException e) {
        throw new ConnectionException(Activator.createErrorStatus(e.getMessage(), e));
      }
    }

View Full Code Here




    NNTPClient client;


    public ExtendedNNTPOps() {
        client = new NNTPClient();
        client.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out), true));
    }

View Full Code Here

        {
            System.err.println("Usage: newsgroups newsserver [pattern]");
            return;
        }


        NNTPClient client = new NNTPClient();
        String pattern = args.length >= 2 ? args[1] : "";


        try
        {
            client.connect(args[0]);


            int j = 0;
            try {
                for(String s : client.iterateNewsgroupListing(pattern)) {
                    j++;
                    System.out.println(s);
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            System.out.println(j);


            j = 0;
            for(NewsgroupInfo n : client.iterateNewsgroups(pattern)) {
                j++;
                System.out.println(n.getNewsgroup());
            }
            System.out.println(j);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            try
            {
                if (client.isConnected()) {
                    client.disconnect();
                }
            }
            catch (IOException e)
            {
                System.err.println("Error disconnecting from server.");

View Full Code Here

        String from, subject, newsgroup, filename, server, organization;
        String references;
        BufferedReader stdin;
        FileReader fileReader = null;
        SimpleNNTPHeader header;
        NNTPClient client;


        if (args.length < 1)
        {
            System.err.println("Usage: post newsserver");
            System.exit(1);
        }


        server = args[0];


        stdin = new BufferedReader(new InputStreamReader(System.in));


        try
        {
            System.out.print("From: ");
            System.out.flush();


            from = stdin.readLine();


            System.out.print("Subject: ");
            System.out.flush();


            subject = stdin.readLine();


            header = new SimpleNNTPHeader(from, subject);


            System.out.print("Newsgroup: ");
            System.out.flush();


            newsgroup = stdin.readLine();
            header.addNewsgroup(newsgroup);


            while (true)
            {
                System.out.print("Additional Newsgroup <Hit enter to end>: ");
                System.out.flush();


                // Of course you don't want to do this because readLine() may be null
                newsgroup = stdin.readLine().trim();


                if (newsgroup.length() == 0) {
                    break;
                }


                header.addNewsgroup(newsgroup);
            }


            System.out.print("Organization: ");
            System.out.flush();


            organization = stdin.readLine();


            System.out.print("References: ");
            System.out.flush();


            references = stdin.readLine();


            if (organization != null && organization.length() > 0) {
                header.addHeaderField("Organization", organization);
            }


            if (references != null && references.length() > 0) {
                header.addHeaderField("References", references);
            }


            header.addHeaderField("X-Newsreader", "NetComponents");


            System.out.print("Filename: ");
            System.out.flush();


            filename = stdin.readLine();


            try
            {
                fileReader = new FileReader(filename);
            }
            catch (FileNotFoundException e)
            {
                System.err.println("File not found. " + e.getMessage());
                System.exit(1);
            }


            client = new NNTPClient();
            client.addProtocolCommandListener(new PrintCommandListener(
                                                  new PrintWriter(System.out), true));


            client.connect(server);


            if (!NNTPReply.isPositiveCompletion(client.getReplyCode()))
            {
                client.disconnect();
                System.err.println("NNTP server refused connection.");
                System.exit(1);
            }


            if (client.isAllowedToPost())
            {
                Writer writer = client.postArticle();


                if (writer != null)
                {
                    writer.write(header.toString());
                    Util.copyReader(fileReader, writer);
                    writer.close();
                    client.completePendingCommand();
                }
            }


            if (fileReader != null) {
                fileReader.close();
            }


            client.logout();


            client.disconnect();
        }
        catch (IOException e)
        {
            e.printStackTrace();
            System.exit(1);

View Full Code Here

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com.xmultra.processor.net.NntpProcessor

examples.ExtendedNNTPOps

examples.newsgroups

examples.nntp.ArticleReader

examples.nntp.ExtendedNNTPOps

examples.nntp.ListNewsgroups

examples.nntp.MessageThreading

examples.nntp.newsgroups

examples.nntp.post

examples.nntp.PostMessage

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