¿Cómo construir un lector de RSS para Android?

rss-reader

Question

Soy nuevo en Android y estoy tratando de construir un lector de RSS para Android. He construido todas las clases y archivos XML pero no da el resultado requerido. Solo está mostrando el mensaje No RSS feed available .

Por favor, alguien puede sugerir qué debo hacer.

Aquí está el código que tomé del tutorial y traté de manipular

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
}
}

Answer 1

Este es mi primer acercamiento a RSS Reader. No es tan dinámico y tiene un código de referencia pero funcionó bien para mí.

Uso:

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

Clase:

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 2

Hay un tutorial (que incluye el código fuente completo) sobre cómo crear un redactor de RSS de Android aquí:

parte 1 (solicitud completa)

parte 2 (aplicación actualizada para analizar etiquetas de imagen desde la descripción)

parte 3 (actualización de la aplicación con Android 3.0)

El tutorial utiliza el analizador SAX e incluye un proyecto completo de Android que accede a una fuente RSS y luego la muestra en una vista de lista.

Parece que hay mucha gente interesada en esto, así que si está buscando un Android 3.0+ con tareas de fragmentos / asíncronos, etc., así como un código completo de la aplicación, he actualizado las publicaciones nuevamente, y las puede encontrar aquí. !

Answer 3

Puedes descargar y revisar mi proyecto en google-play . Este proyecto trata sobre algunos canales turcos de alimentación deportiva. Muchos canales están en una aplicación.

Puede consultar el código fuente del proyecto en github .

Answer 4

Verifique el siguiente enlace, Es un lector de RSS de código abierto para Android. Puede descargar el código como referencia.

code.google.com/p/android-rss

Answer 5

Analice este tipo de XmlPullParser fácilmente utilizando 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;
}
}