How to Build a RSS reader for Android?

Question

I am new to android and i am trying to build a RSS reader for Android. I have built all the classes and XML files but its not giving the required output. Its just showing the message No RSS feed available.

Please can some one suggest what should i do.

Here is the code which i took from the tutorial and tried to manipulate-

public final String RSSFEEDOFCHOICE = "http://blog.01synergy.com/feed/";

public final String tag = "RSSReader";
private RSSFeed feed = null;

/** Called when the activity is first created. */

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.main);

    // go get our feed!
    feed = getFeed(RSSFEEDOFCHOICE);

    // display UI
    UpdateDisplay();

}


private RSSFeed getFeed(String urlToRssFeed)
{
    try
    {
        // setup the url
       URL url = new URL(urlToRssFeed);

       // create the factory
       SAXParserFactory factory = SAXParserFactory.newInstance();
       // create a parser
       SAXParser parser = factory.newSAXParser();

       // create the reader (scanner)
       XMLReader xmlreader = parser.getXMLReader();
       // instantiate our handler
       RSSHandler theRssHandler = new RSSHandler();
       // assign our handler
       xmlreader.setContentHandler(theRssHandler);
       // get our data via the url class
       InputSource is = new InputSource(url.openStream());
       // perform the synchronous parse           
       xmlreader.parse(is);
       // get the results - should be a fully populated RSSFeed instance, or null on error
       return theRssHandler.getFeed();
    }
    catch (Exception ee)
    {
        // if we have a problem, simply return null
        return null;
    }
}
public boolean onCreateOptionsMenu(Menu menu) 
{
    super.onCreateOptionsMenu(menu);

    menu.add(0,0,0, "Choose RSS Feed");
    menu.add(0,1,0, "Refresh");
    Log.i(tag,"onCreateOptionsMenu");
    return true;
}

public boolean onOptionsItemSelected(Menu item){
    switch (((View) item).getId()) {
    case 0:

        Log.i(tag,"Set RSS Feed");
        return true;
    case 1:
        Log.i(tag,"Refreshing RSS Feed");
        return true;
    }
    return false;
}


private void UpdateDisplay()
{
    TextView feedtitle = (TextView) findViewById(R.id.feedtitle);
    TextView feedpubdate = (TextView) findViewById(R.id.feedpubdate);
    ListView itemlist = (ListView) findViewById(R.id.itemlist);


    if (feed == null)
    {
        feedtitle.setText("No RSS Feed Available");
        return;
    }

    feedtitle.setText(feed.getTitle());
    feedpubdate.setText(feed.getPubDate());

    ArrayAdapter<RSSItem> adapter = new ArrayAdapter<RSSItem>(this,android.R.layout.simple_list_item_1,feed.getAllItems());

    itemlist.setAdapter(adapter);

    itemlist.setOnItemClickListener(this);

    itemlist.setSelection(0);

}


 public void onItemClick(AdapterView parent, View v, int position, long id)
 {
     Log.i(tag,"item clicked! [" + feed.getItem(position).getTitle() + "]");

     Intent itemintent = new Intent(this,ShowDescription.class);

     Bundle b = new Bundle();
     b.putString("title", feed.getItem(position).getTitle());
     b.putString("description", feed.getItem(position).getDescription());
     b.putString("link", feed.getItem(position).getLink());
     b.putString("pubdate", feed.getItem(position).getPubDate());

     itemintent.putExtra("android.intent.extra.INTENT", b);

     startSubActivity(itemintent,0);
 }


private void startSubActivity(Intent itemintent, int i) {
    // TODO Auto-generated method stub

}

}

Centipede

your question is hard to answer but if you like you take a look at these code.google.com/p/android-rss – Bestride

Can you please post your code. – Sp

hello if you can provide code then I can identify the problem in your code – As

possible duplicate of Simple RSS parser for Android – Debark

thanx to all for help .I changed my website for the feed now its showing the feed but not the descrition of that on click of list item in the listview. – Centipede

Answer 1

Check following link, It's open source RSS reader for Android, You can download code for reference

http://code.google.com/p/android-rss/

As

we post thing all most same time. :-) – As

thanx for help KPBird and subspider, i have seen this site, but i have given my more to time to the tutorial of ibm, can you suggest me something related to that. – Centipede

I changed my website for the feed now its showing the feed but not the descrition of the item on click of list item in the listview can you please help me to achieve it.My program is showing no error. – Centipede

It has GPL license. Doesn't it mean that no matter what app you create, your app needs to be open sourced too? – Clueless

Answer 2

This is my first approach to RSS Reader, It's no so dynamic and has boilerplate code but worked well for myself.

Usage:

RssParser parser = new RssParser(feedUrl);
Log.i("LOG", "Description: " + parser.getItem(3).description); //4th item's description

Class:

package com.uncocoder.course.app.feed_reader;

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import android.util.Log;


public class RssParser extends DefaultHandler {

    private StringBuilder   content;
    private boolean         inChannel;
    private boolean         inImage;
    private boolean         inItem;

    private ArrayList<Item> items   = new ArrayList<Item>();
    private Channel         channel = new Channel();

    private Item            lastItem;


    public RssParser(String url) {
        try {
            SAXParserFactory spf = SAXParserFactory.newInstance();
            SAXParser sp = spf.newSAXParser();
            XMLReader xr = sp.getXMLReader();
            URL sourceUrl = new URL(url);
            xr.setContentHandler(this);
            xr.parse(new InputSource(sourceUrl.openStream()));
        }
        catch (ParserConfigurationException e) {
            e.printStackTrace();
        }
        catch (SAXException e) {
            e.printStackTrace();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }


    public class Item {

        public String title;
        public String description;
        public String link;
        public String category;
        public String pubDate;
        public String guid;
    }


    public class Channel {

        public String title;
        public String description;
        public String link;
        public String lastBuildDate;
        public String generator;
        public String imageUrl;
        public String imageTitle;
        public String imageLink;
        public String imageWidth;
        public String imageHeight;
        public String imageDescription;
        public String language;
        public String copyright;
        public String pubDate;
        public String category;
        public String ttl;
    }


    @Override
    public void startDocument() throws SAXException {
        Log.i("LOG", "StartDocument");
    }


    @Override
    public void endDocument() throws SAXException {
        Log.i("LOG", "EndDocument");
    }


    @Override
    public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
        if (localName.equalsIgnoreCase("image")) {
            inImage = true;
        }

        if (localName.equalsIgnoreCase("channel")) {
            inChannel = true;
        }

        if (localName.equalsIgnoreCase("item")) {
            lastItem = new Item();
            items.add(lastItem);
            inItem = true;
        }

        content = new StringBuilder();
    }


    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if (localName.equalsIgnoreCase("image")) {
            inImage = false;
        }

        if (localName.equalsIgnoreCase("channel")) {
            inChannel = false;
        }

        if (localName.equalsIgnoreCase("item")) {
            inItem = false;
        }

        if (localName.equalsIgnoreCase("title")) {
            if (content == null) {
                return;
            }

            if (inItem) {
                lastItem.title = content.toString();
            } else if (inImage) {
                channel.imageTitle = content.toString();
            } else if (inChannel) {
                channel.title = content.toString();
            }

            content = null;
        }

        if (localName.equalsIgnoreCase("description")) {
            if (content == null) {
                return;
            }

            if (inItem) {
                lastItem.description = content.toString();
            } else if (inImage) {
                channel.imageDescription = content.toString();
            } else if (inChannel) {
                channel.description = content.toString();
            }

            content = null;
        }

        if (localName.equalsIgnoreCase("link")) {
            if (content == null) {
                return;
            }

            if (inItem) {
                lastItem.link = content.toString();
            } else if (inImage) {
                channel.imageLink = content.toString();
            } else if (inChannel) {
                channel.link = content.toString();
            }

            content = null;
        }

        if (localName.equalsIgnoreCase("category")) {
            if (content == null) {
                return;
            }

            if (inItem) {
                lastItem.category = content.toString();
            } else if (inChannel) {
                channel.category = content.toString();
            }

            content = null;
        }

        if (localName.equalsIgnoreCase("pubDate")) {
            if (content == null) {
                return;
            }

            if (inItem) {
                lastItem.pubDate = content.toString();
            } else if (inChannel) {
                channel.pubDate = content.toString();
            }

            content = null;
        }

        if (localName.equalsIgnoreCase("guid")) {
            if (content == null) {
                return;
            }

            lastItem.guid = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("url")) {
            if (content == null) {
                return;
            }

            channel.imageUrl = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("width")) {
            if (content == null) {
                return;
            }

            channel.imageWidth = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("height")) {
            if (content == null) {
                return;
            }

            channel.imageHeight = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("language")) {
            if (content == null) {
                return;
            }

            channel.language = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("copyright")) {
            if (content == null) {
                return;
            }

            channel.copyright = content.toString();
            content = null;
        }

        if (localName.equalsIgnoreCase("ttl")) {
            if (content == null) {
                return;
            }

            channel.ttl = content.toString();
            content = null;
        }
    }


    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        if (content == null) {
            return;
        }

        content.append(ch, start, length);
    }


    public Item getItem(int index) {
        return items.get(index);
    }
}

Bloodfin

Answer 3

There is a tutorial (including complete source code) on how to build an Android RSS reder here:

part 1 (complete application)

part 2 (application updated to parse image tags from desciption)

part 3 (application update with Android 3.0)

The tutorial uses SAX parser and includes a complete Android project that accesses an RSS feed and then displays the feed in a list view.

There still seems to be a lot of people interested in this - so if you are looking for an Android 3.0+ with fragments/async tasks etc, as well as complete application code, I have updated the posts again, and they can be found here!

Chuch

Answer 4

You can download and check my project on google-play. This project is about some turkish sport channels feeds. Lots of channels are in one application.

You can check source code of project on github.

Monday

What is the license to it? Also, is it possible to tell it to load only the most recent post of the RSS feed ? – Clueless

I added the license file. Yes it loads most recent rss feeds. @androiddeveloper – Monday

I meant, if I can tell it how many. If I only need 1, it will load just it, without the need to parse the others. – Clueless

You can set this variable in RssHandler class as ARTICLES_LIMIT. This will show you how many feeds do you want to load. @androiddeveloper – Monday

Answer 5

Parse this type of Rss Feeds easily using XmlPullParser

     public class RSSParser {

public static ArrayList<Pojo> getParserData(String Data){
    try {
        RSSXMLTag currentTag = null;
        ArrayList<Pojo> postDataList = new ArrayList<>();
        XmlPullParserFactory factory = XmlPullParserFactory
                .newInstance();
        factory.setNamespaceAware(true);
        XmlPullParser xpp = factory.newPullParser();
        xpp.setInput(new StringReader(Data));

        int eventType = xpp.getEventType();
        Pojo pdData = null;
        SimpleDateFormat dateFormat = new SimpleDateFormat(
                "EEEE, DD MMM yyyy ");
        while (eventType != XmlPullParser.END_DOCUMENT) {
            int i = 0;
            if (eventType == XmlPullParser.START_DOCUMENT) {

            } else if (eventType == XmlPullParser.START_TAG) {
                if (xpp.getName().equals("item")) {

                    pdData = new Pojo();

                    currentTag = RSSXMLTag.IGNORETAG;
                } else if (xpp.getName().equals("title")) {
                    currentTag = RSSXMLTag.TITLE;
                } else if (xpp.getName().equals("link")) {
                    currentTag = RSSXMLTag.LINK;
                } else if (xpp.getName().equals("pubDate")) {
                    currentTag = RSSXMLTag.DATE;
                } else if (xpp.getName().equals("creator")) {

                    currentTag = RSSXMLTag.CREATOR;
                } else if (xpp.getName().equals("category")) {
                    currentTag = RSSXMLTag.CATEGORY;
                } else if (xpp.getName().equals("description")) {
                    currentTag = RSSXMLTag.DESCRIPTION;
                }
            } else if (eventType == XmlPullParser.END_TAG) {
                if (xpp.getName().equals("item")) {
                    // format the data here, otherwise format data in
                    // Adapter
                    Date postDate = dateFormat.parse(pdData.postDate);
                    pdData.postDate = dateFormat.format(postDate);
                    postDataList.add(pdData);
                } else {
                    currentTag = RSSXMLTag.IGNORETAG;
                }
            } else if (eventType == XmlPullParser.TEXT) {
                String content = xpp.getText();
                content = content.trim();
                Log.d("debug", content);
                if (pdData != null) {
                    switch (currentTag) {
                        case TITLE:
                            if (content.length() != 0) {
                                if (pdData.postTitle != null) {
                                    pdData.postTitle += content;
                                } else {
                                    pdData.postTitle = content;
                                }
                            }
                            break;
                        case LINK:
                            if (content.length() != 0) {
                                if (pdData.postLink != null) {
                                    pdData.postLink += content;
                                } else {
                                    pdData.postLink = content;
                                }
                            }
                            break;
                        case DATE:
                            if (content.length() != 0) {
                                if (pdData.postDate != null) {
                                    pdData.postDate += content;
                                } else {
                                    pdData.postDate = content;
                                }
                            }
                            break;
                        case CATEGORY:
                            if (content.length() != 0) {
                                if (pdData.postCategory != null) {
                                    i = i + 1;
                                    if (i == 1) {
                                        pdData.postCategory = content;
                                    }
                                } else {
                                    i = i + 1;
                                    if (i == 1) {
                                        pdData.postCategory = content;
                                    }
                                }
                            }
                            break;
                        case DESCRIPTION:
                            if (content.length() != 0) {
                                if (pdData.postDescription != null) {
                                    String s = content;

                                    String string = s.substring(s.indexOf("src=\"") + 5, s.indexOf("\" class=\""));
                                    pdData.postDescription += string;
                                } else {
                                    String s = content;

                                    String string = s.substring(s.indexOf("src=\"") + 5, s.indexOf("\" class=\""));
                                    pdData.postDescription = string;
                                }
                            }
                            break;
                        case CREATOR:
                            if (content.length() != 0) {
                                if (pdData.postCreator != null) {
                                    pdData.postCreator += content;
                                } else {
                                    pdData.postCreator = content;
                                }
                            }
                            break;
                        default:
                            break;
                    }
                }
            }

            eventType = xpp.next();
        }
        return postDataList;
    }catch (Exception e){
        e.printStackTrace();
    }

    return null;
}

public enum RSSXMLTag {
    IGNORETAG, TITLE, LINK, DATE,CREATOR,CATEGORY, DESCRIPTION;
}


public class Pojo {


public String getPostTitle() {
    return postTitle;
}

public void setPostTitle(String postTitle) {
    this.postTitle = postTitle;
}

public String getPostLink() {
    return postLink;
}

public void setPostLink(String postLink) {
    this.postLink = postLink;
}

public String getPostDate() {
    return postDate;
}

public void setPostDate(String postDate) {
    this.postDate = postDate;
}

public String getPostCategory() {
    return postCategory;
}

public void setPostCategory(String postCategory) {
    this.postCategory = postCategory;
}

public String getPostDescription() {
    return postDescription;
}

public void setPostDescription(String postDescription) {
    this.postDescription = postDescription;
}

public String getPostCreator() {
    return postCreator;
}

public void setPostCreator(String postCreator) {
    this.postCreator = postCreator;
}

public String postTitle;

public String postLink;

public String postDate;

public String postCategory;

public String postDescription;
public String postCreator;
}


}

Adachi