package utils.vogella;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.XMLEvent;
public class RSSFeedParser {
static final String TITLE = "title";
static final String DESCRIPTION = "description";
static final String CHANNEL = "channel";
static final String LANGUAGE = "language";
static final String COPYRIGHT = "copyright";
static final String LINK = "link";
static final String AUTHOR = "author";
static final String ITEM = "item";
static final String PUB_DATE = "pubDate";
static final String GUID = "guid";
final URL url;
public RSSFeedParser(String feedUrl) {
try {
this.url = new URL(feedUrl);
} catch (MalformedURLException e) {
throw new RuntimeException(e);
}
}
public Feed readFeed() {
Feed feed = null;
try {
boolean isFeedHeader = true;
// Set header values intial to the empty string
String description = "";
String title = "";
String link = "";
String language = "";
String copyright = "";
String author = "";
String pubdate = "";
String guid = "";
// First create a new XMLInputFactory
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
// Setup a new eventReader
InputStream in = read();
XMLEventReader eventReader = inputFactory.createXMLEventReader(in);
// read the XML document
while (eventReader.hasNext()) {
XMLEvent event = eventReader.nextEvent();
if (event.isStartElement()) {
String localPart = event.asStartElement().getName()
.getLocalPart();
if(localPart.equals(ITEM)){
if (isFeedHeader) {
isFeedHeader = false;
feed = new Feed(title, link, description, language,
copyright, pubdate);
}
event = eventReader.nextEvent();
}
if(localPart.equals(TITLE)){
title = getCharacterData(event, eventReader);
}
if(localPart.equals(DESCRIPTION)){
description = getCharacterData(event, eventReader);
}
if(localPart.equals(LINK)){
link = getCharacterData(event, eventReader);
}
if(localPart.equals(GUID)){
guid = getCharacterData(event, eventReader);
}
if(localPart.equals(LANGUAGE)){
language = getCharacterData(event, eventReader);
}
if(localPart.equals(AUTHOR)){
author = getCharacterData(event, eventReader);
}
if(localPart.equals(PUB_DATE)){
pubdate = getCharacterData(event, eventReader);
}
if(localPart.equals(COPYRIGHT)){
copyright = getCharacterData(event, eventReader);
}
}
if (event.isEndElement()) {
if (event.asEndElement().getName().getLocalPart() == (ITEM)) {
FeedMessage message = new FeedMessage();
message.setAuthor(author);
message.setDescription(description);
message.setGuid(guid);
message.setLink(link);
message.setTitle(title);
feed.getMessages().add(message);
event = eventReader.nextEvent();
continue;
}
}
}
} catch (XMLStreamException e) {
throw new RuntimeException(e);
}
return feed;
}
private String getCharacterData(XMLEvent event, XMLEventReader eventReader)
throws XMLStreamException {
String result = "";
event = eventReader.nextEvent();
if (event instanceof Characters) {
result = event.asCharacters().getData();
}
return result;
}
private InputStream read() {
try {
return url.openStream();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}