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 th

Answer 1

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;
}


}

Answer 2

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!

Answer 3

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);
    }
}

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.

Answer 5

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

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