org.sonews.daemon.command.XPatCommand.java Source code

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Here is the source code for org.sonews.daemon.command.XPatCommand.java

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/*
 *   SONEWS News Server
 *   Copyright (C) 2009-2015  Christian Lins <christian@lins.me>
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.sonews.daemon.command;

import java.io.IOException;
import java.util.List;
import java.util.Locale;
import java.util.regex.PatternSyntaxException;

import org.sonews.daemon.NNTPConnection;
import org.sonews.storage.StorageBackendException;
import org.sonews.storage.StorageManager;
import org.sonews.util.Pair;

import org.springframework.stereotype.Component;

/**
 * <pre>
 *   XPAT header range|<message-id> pat [pat...]
 *
 *   The XPAT command is used to retrieve specific headers from
 *   specific articles, based on pattern matching on the contents of
 *   the header. This command was first available in INN.
 *
 *   The required header parameter is the name of a header line (e.g.
 *   "subject") in a news group article. See RFC-1036 for a list
 *   of valid header lines. The required range argument may be
 *   any of the following:
 *               an article number
 *               an article number followed by a dash to indicate
 *                  all following
 *               an article number followed by a dash followed by
 *                  another article number
 *
 *   The required message-id argument indicates a specific
 *   article. The range and message-id arguments are mutually
 *   exclusive. At least one pattern in wildmat must be specified
 *   as well. If there are additional arguments the are joined
 *   together separated by a single space to form one complete
 *   pattern. Successful responses start with a 221 response
 *   followed by a the headers from all messages in which the
 *   pattern matched the contents of the specified header line. This
 *   includes an empty list. Once the output is complete, a period
 *   is sent on a line by itself. If the optional argument is a
 *   message-id and no such article exists, the 430 error response
 *   is returned. A 502 response will be returned if the client only
 *   has permission to transfer articles.
 *
 *   Responses
 *
 *       221 Header follows
 *       430 no such article
 *       502 no permission
 *
 *   Response Data:
 *
 *       art_nr fitting_header_value
 *
 * </pre>
 *
 * [Source:"draft-ietf-nntp-imp-02.txt"] [Copyright: 1998 S. Barber]
 *
 * @author Christian Lins
 * @since sonews/0.5.0
 */
@Component
public class XPatCommand implements Command {

    @Override
    public String[] getSupportedCommandStrings() {
        return new String[] { "XPAT" };
    }

    @Override
    public boolean hasFinished() {
        return true;
    }

    @Override
    public String impliedCapability() {
        return null;
    }

    @Override
    public boolean isStateful() {
        return false;
    }

    @Override
    public void processLine(NNTPConnection conn, final String line, byte[] raw)
            throws IOException, StorageBackendException {
        if (conn.getCurrentGroup() == null) {
            conn.println("430 no group selected");
            return;
        }

        String[] command = line.split("\\p{Space}+");

        // There may be multiple patterns and Thunderbird produces
        // additional spaces between range and pattern
        if (command.length >= 4) {
            String header = command[1].toLowerCase(Locale.US);
            String range = command[2];
            String pattern = command[3];

            long start = -1;
            long end = -1;
            if (range.contains("-")) {
                String[] rsplit = range.split("-", 2);
                start = Long.parseLong(rsplit[0]);
                if (rsplit[1].length() > 0) {
                    end = Long.parseLong(rsplit[1]);
                }
            } else // TODO: Handle Message-IDs
            {
                start = Long.parseLong(range);
            }

            try {
                List<Pair<Long, String>> heads = StorageManager.current().getArticleHeaders(conn.getCurrentGroup(),
                        start, end, header, pattern);

                conn.println("221 header follows");
                for (Pair<Long, String> head : heads) {
                    conn.println(head.getA() + " " + head.getB());
                }
                conn.println(".");
            } catch (PatternSyntaxException ex) {
                ex.printStackTrace();
                conn.println("500 invalid pattern syntax");
            } catch (StorageBackendException ex) {
                ex.printStackTrace();
                conn.println("500 internal server error");
            }
        } else {
            conn.println("430 invalid command usage");
        }
    }
}