rssservlet.java

一个java实现rss的示例

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

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.sun.syndication.feed.synd.SyndContent;
import com.sun.syndication.feed.synd.SyndContentImpl;
import com.sun.syndication.feed.synd.SyndEntry;
import com.sun.syndication.feed.synd.SyndEntryImpl;
import com.sun.syndication.feed.synd.SyndFeed;
import com.sun.syndication.feed.synd.SyndFeedImpl;
import com.sun.syndication.io.FeedException;
import com.sun.syndication.io.SyndFeedOutput;

@SuppressWarnings("serial")
public class RssServlet extends HttpServlet {
	
	private static final String DEFAULT_FEED_TYPE = "default.feed.type";
    private static final String MIME_TYPE = "application/xml; charset=UTF-8";
    private static final String DEFAULT_RSSCOUNT = "default.rss.count";
    private String _defaultFeedType;
    private String rssCount;
    
    public void init() {
        _defaultFeedType = getServletConfig().getInitParameter(DEFAULT_FEED_TYPE);
        _defaultFeedType = (_defaultFeedType!=null) ? _defaultFeedType : "atom_0.3";
        rssCount = getServletConfig().getInitParameter(DEFAULT_RSSCOUNT);
        rssCount = (rssCount != null) ? rssCount : "20";
    }
    
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request, response);
	}

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		try {
            String feedType = request.getParameter("feedType");
            if(feedType==null)feedType=request.getParameter("t");
            int channelId = Integer.parseInt(request.getParameter("id") == null ? "0":request.getParameter("id"));
            
            SyndFeed feed = getFeed(feedType, channelId, request, getServletContext());
            feed.setFeedType(_defaultFeedType);

            response.setContentType(MIME_TYPE);
            SyndFeedOutput output = new SyndFeedOutput();
            output.output(feed,response.getWriter());
        }
        catch (FeedException ex) {
            //String msg = COULD_NOT_GENERATE_FEED_ERROR;
            //log(msg,ex);
            ex.printStackTrace();
        }
	}
	
	protected SyndFeed getFeed(String type, int channelId, HttpServletRequest request, ServletContext servletContext) throws IOException,FeedException{
        if("channel".equals(type))
        	return getChannelsFeed(channelId,request,servletContext);
        else if("article".equals(type))
        	return getArticlesFeed(channelId,request,servletContext);
        else 
        	return null;
	}
	
	protected SyndFeed getTestFeed(int channelId, HttpServletRequest request, ServletContext servletContext){
		SyndFeed feed = new SyndFeedImpl();

        feed.setTitle("Title");
        feed.setLink("URL");
        feed.setDescription("Descript");
        feed.setCopyright("sitenme");
        feed.setLanguage("zh-cn");
	
		feed.setEntries(entries);
		return feed;
	}

	
	public static void main(String[] args){

	}
}