src/org/sonews/daemon/command/NextPrevCommand.java
author cli
Sat, 10 Sep 2011 18:18:05 +0200
changeset 45 7e24949b87b0
parent 37 74139325d305
child 48 b78e77619152
permissions -rwxr-xr-x
HSQLDB backend support completed, but untested.
     1 /*
     2  *   SONEWS News Server
     3  *   see AUTHORS for the list of contributors
     4  *
     5  *   This program is free software: you can redistribute it and/or modify
     6  *   it under the terms of the GNU General Public License as published by
     7  *   the Free Software Foundation, either version 3 of the License, or
     8  *   (at your option) any later version.
     9  *
    10  *   This program is distributed in the hope that it will be useful,
    11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  *   GNU General Public License for more details.
    14  *
    15  *   You should have received a copy of the GNU General Public License
    16  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17  */
    18 
    19 package org.sonews.daemon.command;
    20 
    21 import java.io.IOException;
    22 import org.sonews.daemon.NNTPConnection;
    23 import org.sonews.storage.Article;
    24 import org.sonews.storage.Channel;
    25 import org.sonews.storage.StorageBackendException;
    26 
    27 /**
    28  * Class handling the NEXT and LAST command.
    29  * @author Christian Lins
    30  * @author Dennis Schwerdel
    31  * @since n3tpd/0.1
    32  */
    33 public class NextPrevCommand implements Command
    34 {
    35 
    36 	@Override
    37 	public String[] getSupportedCommandStrings()
    38 	{
    39 		return new String[] {"NEXT", "PREV"};
    40 	}
    41 
    42 	@Override
    43 	public boolean hasFinished()
    44 	{
    45 		return true;
    46 	}
    47 
    48 	@Override
    49 	public String impliedCapability()
    50 	{
    51 		return null;
    52 	}
    53 
    54 	@Override
    55 	public boolean isStateful()
    56 	{
    57 		return false;
    58 	}
    59 
    60 	@Override
    61 	public void processLine(NNTPConnection conn, final String line, byte[] raw)
    62 		throws IOException, StorageBackendException
    63 	{
    64 		final Article currA = conn.getCurrentArticle();
    65 		final Channel currG = conn.getCurrentChannel();
    66 
    67 		if (currA == null) {
    68 			conn.println("420 no current article has been selected");
    69 			return;
    70 		}
    71 
    72 		if (currG == null) {
    73 			conn.println("412 no newsgroup selected");
    74 			return;
    75 		}
    76 
    77 		final String[] command = line.split(" ");
    78 
    79 		if (command[0].equalsIgnoreCase("NEXT")) {
    80 			selectNewArticle(conn, currA, currG, 1);
    81 		} else if (command[0].equalsIgnoreCase("PREV")) {
    82 			selectNewArticle(conn, currA, currG, -1);
    83 		} else {
    84 			conn.println("500 internal server error");
    85 		}
    86 	}
    87 
    88 	private void selectNewArticle(NNTPConnection conn, Article article, Channel grp,
    89 		final int delta)
    90 		throws IOException, StorageBackendException
    91 	{
    92 		assert article != null;
    93 
    94 		article = grp.getArticle(grp.getIndexOf(article) + delta);
    95 
    96 		if (article == null) {
    97 			conn.println("421 no next article in this group");
    98 		} else {
    99 			conn.setCurrentArticle(article);
   100 			conn.println("223 " + conn.getCurrentChannel().getIndexOf(article)
   101 				+ " " + article.getMessageID()
   102 				+ " article retrieved - request text separately");
   103 		}
   104 	}
   105 }