io.dimitris.newsgroupwatcher.NewsgroupWatcher.java Source code

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Here is the source code for io.dimitris.newsgroupwatcher.NewsgroupWatcher.java

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/*******************************************************************************
 * Copyright (c) 2008 The University of York.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Dimitrios Kolovos - initial API and implementation
******************************************************************************/

package io.dimitris.newsgroupwatcher;

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;

import org.apache.commons.net.nntp.NNTPClient;
import org.apache.commons.net.nntp.NewsgroupInfo;

public class NewsgroupWatcher {

    protected String server;
    protected String newsgroup;
    protected String username;
    protected String password;
    protected boolean authenticationRequired;
    protected NNTPClient client;
    protected long interval = 1000;
    protected boolean watching = false;
    protected int articleCount = -1;

    protected ArrayList<NewArticleListener> newArticleListeners = new ArrayList<NewArticleListener>();

    public void startWatching() throws IOException {
        watching = true;
        watch();
    }

    protected void sleep() {
        try {
            Thread.currentThread().sleep(interval);
        } catch (InterruptedException e) {

        }
    }

    protected void watch() throws IOException {

        while (watching) {
            try {
                //System.err.println("Watching ");
                client = new NNTPClient();
                client.connect(server);
                if (isAuthenticationRequired()) {
                    client.authenticate(username, password);
                }

                client.selectNewsgroup(newsgroup);

                NewsgroupInfo newsgroupInfo = null;

                for (NewsgroupInfo ni : client.listNewsgroups()) {

                    if (ni.getNewsgroup().equals(newsgroup)) {
                        newsgroupInfo = ni;
                        break;
                    }
                }

                int newArticleCount = newsgroupInfo.getArticleCount();

                //if (articleCount == -1) {
                //   articleCount = newArticleCount;
                //}
                //else 
                if (articleCount < newArticleCount) {
                    Reader articleReader = client.retrieveArticleHeader(newArticleCount);
                    notifyNewArticleListeners(new ArticleHeader(articleReader));
                    articleCount = newArticleCount;
                } else {
                    //System.err.println("Still " + newArticleCount);
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            } finally {
                sleep();
            }
        }
    }

    public void stopWatching() {
        watching = false;
    }

    protected void notifyNewArticleListeners(ArticleHeader header) {

        for (NewArticleListener listener : newArticleListeners) {
            listener.newArticle(header);
        }
    }

    public void addNewArticleListener(NewArticleListener listener) {
        newArticleListeners.add(listener);
    }

    public void removeNewArticleListener(NewArticleListener listener) {
        newArticleListeners.remove(listener);
    }

    public long getInterval() {
        return interval;
    }

    public void setInterval(long interval) {
        this.interval = interval;
    }

    public String getServer() {
        return server;
    }

    public void setServer(String server) {
        this.server = server;
    }

    public String getNewsgroup() {
        return newsgroup;
    }

    public void setNewsgroup(String newsgroup) {
        this.newsgroup = newsgroup;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public boolean isAuthenticationRequired() {
        return authenticationRequired;
    }

    public void setAuthenticationRequired(boolean authenticationRequired) {
        this.authenticationRequired = authenticationRequired;
    }

    public ArrayList<NewArticleListener> getNewMessageListeners() {
        return newArticleListeners;
    }

    public void setNewMessageListeners(ArrayList<NewArticleListener> newMessageListeners) {
        this.newArticleListeners = newMessageListeners;
    }

}