Abdera, a Java AtomPub
implementation
David Calavera
11870.com

vanity slide
•Software architect at 11870.com
• Open source “aholic”: Hudson, Netbeans
• Commiter of the Apache Abdera project

Overview
•Atom Publishing Protocol implementation
• Atom Syndication Format implementation
• version 0.5 comming soon

Creating feeds
Abdera abdera = new Abdera();
Feed feed = abdera.newFeed();
feed.setId(\"tag:example.org,2008:/foo\");
feed.setTitle(\"Test Feed\");
feed.setSubtitle(\"Feed subtitle\");
feed.setUpdated(new Date());
feed.addAuthor(\"David Calavera\");
feed.addLink(\"http://example.com\");
feed.addLink(\"http://example.com/foo\",\"self\");
Entry entry = feed.addEntry();
entry.setId(\"tag:example.org,2007:/foo/entries/1\");
entry.setTitle(\"Entry title\");
entry.setSummaryAsHtml(\"<p>This is the entry title</p>\");
entry.setUpdated(new Date());

Reading feeds
Abdera abdera = new Abdera();
Parser parser = abdera.getParser();
URL url = new URL(\"http://example.org/feed\");
Document<Feed> doc = parser.parse(url.openStream(),url);
Feed feed = doc.getRoot();
System.out.println(feed.getTitle());
for (Entry entry : feed.getEntries()) {
System.out.println(\"\\t\" + entry.getTitle());
}

How does a server work?
• from top to bottom
• AbderaServlet
• RequestContext
• AbderaFilters
• Provider
• TargetResolver
• RequestProcessor
• Adapter

Target resolvers
• RouteManager
TargetResolver ts = new RouteManager()
.addRoute(\"service\", \"/\", TargetType.TYPE_SERVICE)
.addRoute(\"feed\", \"/:collection\", TargetType.TYPE_COLLECTION)
.addRoute(\"entry\", \"/:collection/:entry:\", TargetType.TYPE_ENTRY)
.addRoute(\"openSearch\", \"/os.xml\", CustomTargetType.OPEN_SEARCH);
• RegexTargetResolver
TargetResolver ts = new RegexTargetResolver()
.setPattern(\"/atom(\\\\?[^#]*)?\", TargetType.TYPE_SERVICE)
.setPattern(\"/atom/([^/#?;]+)$\", TargetType.TYPE_COLLECTION)
.setPattern(\"/atom/([^/#?]+)/([^/#?]+)$\", TargetType.TYPE_ENTRY)
.setPattern(\"/os.xml\", CustomTargetType.OPEN_SEARCH);

Adapters
• CollectionAdapter
ResponseContext postEntry(RequestContext request);
ResponseContext deleteEntry(RequestContext request);
ResponseContext getEntry(RequestContext request);
ResponseContext headEntry(RequestContext request);
ResponseContext optionsEntry(RequestContext request);
ResponseContext putEntry(RequestContext request);
ResponseContext getFeed(RequestContext request);
ResponseContext getCategories(RequestContext request);

Adapters
• MediaCollectionAdapter
ResponseContext postMedia(RequestContext request);
ResponseContext deleteMedia(RequestContext request);
ResponseContext getMedia(RequestContext request);
ResponseContext headMedia(RequestContext request);
ResponseContext optionsMedia(RequestContext request);
ResponseContext putMedia(RequestContext request);

More stuff
• Spring integration
• Multipart media creation
• OAuth
• Open search
• JSON Serialization
• Custom writers
• Pre-built adapters

Questions?
• Resources
• Abdera: http://incubator.apache.org/abdera
• AtomPub: http://ietf.org/rfc/rfc5023
• Atom format: http://ietf.org/rfc/rfc4287
• Atom list: http://www.imc.org/atom-syntax
• My blog: http://thinkincode.net