Java tutorial
/* * 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.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.util.Arrays; import java.util.logging.Level; import javax.mail.MessagingException; import javax.mail.internet.InternetHeaders; import org.sonews.config.Config; import org.sonews.daemon.NNTPConnection; import org.sonews.daemon.sync.SynchronousNNTPConnection; import org.sonews.feed.FeedManager; import org.sonews.storage.Article; import org.sonews.storage.Group; import org.sonews.storage.Headers; import org.sonews.storage.StorageBackendException; import org.sonews.storage.StorageManager; import org.sonews.util.Log; import org.springframework.stereotype.Component; /** * Implementation of the POST command. This command requires multiple lines from * the client, so the handling of asynchronous reading is a little tricky to * handle. * * @author Christian Lins * @since sonews/0.5.0 */ @Component public class PostCommand implements Command { private final Article article = new Article(); private int lineCount = 0; private long bodySize = 0; private InternetHeaders headers = null; private final long maxBodySize = Config.inst().get(Config.ARTICLE_MAXSIZE, 128) * 1024L; // Size // in // bytes private PostState state = PostState.WaitForLineOne; private final ByteArrayOutputStream bufBody = new ByteArrayOutputStream(); private final StringBuilder strHead = new StringBuilder(); @Override public String[] getSupportedCommandStrings() { return new String[] { "POST" }; } @Override public boolean hasFinished() { return this.state == PostState.Finished; } @Override public String impliedCapability() { return null; } @Override public boolean isStateful() { return true; } /** * Process the given line String. line.trim() was called by NNTPConnection. * * @param conn * @param line * @throws java.io.IOException * @throws org.sonews.storage.StorageBackendException */ @Override // TODO: Refactor this method to reduce complexity! public void processLine(NNTPConnection conn, String line, byte[] raw) throws IOException, StorageBackendException { switch (state) { case WaitForLineOne: { if (line.equalsIgnoreCase("POST")) { conn.println("340 send article to be posted. End with <CR-LF>.<CR-LF>"); state = PostState.ReadingHeaders; } else { conn.println("500 invalid command usage"); } break; } case ReadingHeaders: { strHead.append(line); strHead.append(SynchronousNNTPConnection.NEWLINE); if ("".equals(line) || ".".equals(line)) { // we finally met the blank line // separating headers from body try { // Parse the header using the InternetHeader class from // JavaMail API headers = new InternetHeaders( new ByteArrayInputStream(strHead.toString().trim().getBytes(conn.getCurrentCharset()))); // add the header entries for the article article.setHeaders(headers); } catch (MessagingException ex) { Log.get().log(Level.INFO, ex.getLocalizedMessage(), ex); conn.println("500 posting failed - invalid header"); state = PostState.Finished; break; } // Change charset for reading body; // for multipart messages UTF-8 is returned // conn.setCurrentCharset(article.getBodyCharset()); state = PostState.ReadingBody; // WTF: do we need articles without bodies? if (".".equals(line)) { // Post an article without body postArticle(conn, article); state = PostState.Finished; } } break; } case ReadingBody: { if (".".equals(line)) { // Set some headers needed for Over command headers.setHeader(Headers.LINES, Integer.toString(lineCount)); headers.setHeader(Headers.BYTES, Long.toString(bodySize)); byte[] body = bufBody.toByteArray(); if (body.length >= 2) { // Remove trailing CRLF body = Arrays.copyOf(body, body.length - 2); } article.setBody(body); // set the article body postArticle(conn, article); state = PostState.Finished; } else { bodySize += line.length() + 1; lineCount++; // Add line to body buffer bufBody.write(raw, 0, raw.length); bufBody.write(SynchronousNNTPConnection.NEWLINE.getBytes("UTF-8")); if (bodySize > maxBodySize) { conn.println("500 article is too long"); state = PostState.Finished; break; } } break; } default: { // Should never happen Log.get().severe("PostCommand::processLine(): already finished..."); } } } /** * Article is a control message and needs special handling. * * @param article */ private void controlMessage(NNTPConnection conn, Article article) throws IOException { String[] ctrl = article.getHeader(Headers.CONTROL)[0].split(" "); if (ctrl.length == 2) // "cancel <mid>" { try { StorageManager.current().delete(ctrl[1]); // Move cancel message to "control" group article.setHeader(Headers.NEWSGROUPS, "control"); StorageManager.current().addArticle(article); conn.println("240 article cancelled"); } catch (StorageBackendException ex) { Log.get().severe(ex.toString()); conn.println("500 internal server error"); } } else { conn.println("441 unknown control header"); } } private void supersedeMessage(NNTPConnection conn, Article article) throws IOException { try { String oldMsg = article.getHeader(Headers.SUPERSEDES)[0]; StorageManager.current().delete(oldMsg); StorageManager.current().addArticle(article); conn.println("240 article replaced"); } catch (StorageBackendException ex) { Log.get().severe(ex.toString()); conn.println("500 internal server error"); } } private void postArticle(NNTPConnection conn, Article article) throws IOException { article.setUser(conn.getUser()); if (article.getHeader(Headers.CONTROL)[0].length() > 0) { controlMessage(conn, article); } else if (article.getHeader(Headers.SUPERSEDES)[0].length() > 0) { supersedeMessage(conn, article); } else { // Post the article regularily // Circle check; note that Path can already contain the hostname // here String host = Config.inst().get(Config.HOSTNAME, "localhost"); if (article.getHeader(Headers.PATH)[0].indexOf(host + "!", 1) > 0) { Log.get().log(Level.INFO, "{0} skipped for host {1}", new Object[] { article.getMessageID(), host }); conn.println("441 I know this article already"); return; } // Try to create the article in the database or post it to // appropriate mailing list try { boolean success = false; String[] groupnames = article.getHeader(Headers.NEWSGROUPS)[0].split(","); for (String groupname : groupnames) { Group group = Group.get(groupname); if (group != null && !group.isDeleted()) { if (group.isMailingList() /*&& !conn.isLocalConnection()*/) { // Send to mailing list; the Dispatcher writes // statistics to database // FIXME success = Dispatcher.toList(article, // group.getName()); } else { // Store in database if (!StorageManager.current().isArticleExisting(article.getMessageID())) { StorageManager.current().addArticle(article); } success = true; } } } // end for if (success) { conn.println("240 article posted ok"); FeedManager.queueForPush(article); } else { conn.println("441 newsgroup not found or configuration error"); } } catch (StorageBackendException ex) { ex.printStackTrace(); conn.println("500 internal server error"); } } } }