The document discusses REST as an architectural style for web services, utilizing HTTP operations such as GET and POST. It provides examples of how to implement API requests using both Java and JavaScript, while highlighting the need for API keys and handling asynchronous queries. Additionally, it mentions various web services like Flickr, YouTube, and Facebook, emphasizing the importance of accessing data through their respective APIs.

2.  REST is not a protocol or a format its a kind of
architecture
 A service is accessed with its URI through HTTP
operation like GET, POST, PUT or DELETE.
 Enough for most of web services
 Example :
http://www.inria.fr/add?var=1&var=2  3 ;)

3.  Init the HTTP query:
URL url = new URL("my_url");
HttpURLConnection UrlConn = (HttpURLConnection)
url.openConnection();
urlConn.setRequestMethod("GET");
urlConn.setAllowUserInteraction(false);
urlConn.setDoOutput(true);
 Read the answer
InputStream response = urlConn.getInputStream();
BufferedReader br =
new BufferedReader(new InputStreamReader(response));
while ((String line = o_oBufReader.readLine()) != null){
//do whatever you want
}
 Diconnect
urlConn.disconnect();

4.  Asynchronous javascript
 HTTP query in javascript without reloading all the page
 Richer interfaces
 Example: mail notification and instant messaging in gmail.

5. Var xhr;
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest(); // Firefox, Safari, ...
}
else if (window.ActiveXObject) {
xhr = new ActiveXObject("Microsoft.XMLHTTP"); // Internet Explorer
}
or
try {
xhr = new ActiveXObject("Microsoft.XMLHTTP"); //try Internet Explorer
}catch(e) {
xhr = new XMLHttpRequest() //firefox, safari ...
}

6.  Process function :
request.onreadystatechange = function(){
// instructions
};
 Send the query :
xhr.open('GET', 'http://web2/api/method?param=value', true);
xhr.send(null);
 Important: Same Origin Policy
So use a servlet as intermediary

7.  JSON object:
var person = { "name" : "John"
"phone" : [
{"type" : "home", "num" : "1234"},
{"type" : "mobile", "num" : "5678"}
]
};
 person.name; person.phone[0].num;
 Eval function:
var JSONString = "someVar = { 'color' : 'blue' }";
 eval(JSONString);
 Tutorial:
http://www.hunlock.com/blogs/Mastering_JSON_(_JavaScript_Object_Notation_)

8.  API_Key and secret:
http://www.flickr.com/services/api/keys/apply/
Note : il faut un compte Yahoo pour y accèder.
 URL API:
http://api.flickr.com/services/rest/?
method=method_name&param1=value1&param2=va
lue2...
 Paramètre souvent requis: api_key
 On demande la clé en ligne, cf URL ci-dessus.
 Recherche de photos par tags:
http://api.flickr.com/services/rest/?
method=flickr.photos.search&tags=a_tag&api

9.  URL API:
http://api.flickr.com/services/rest/?
method_name&param1=value1&param2=value2...
 Paramètre souvent requis: api_key
 Recherche de photos par tags:
http://api.flickr.com/services/rest/?
method=flickr.photos.search&tags=a_tag&api
_key=your_key

10.  Dom API:
DocumentBuilderFactory fabrique =
DocumentBuilderFactory.newInstance();
DocumentBuilder constructeur =
fabrique.newDocumentBuilder();
Document document = constructeur.parse(rdfFile);
Element racine = document.getDocumentElement();
NodeList photos = racine.getElementsByTagName("photo");
for(int i = 0; i < photos.getLength(); i++){
photos.item(i).getAttributes() …
}
 Or just forget to manipulate XML:
http://sourceforge.net/projects/flickrj/

11.  Init service:
Flickr flickr = new Flickr(apiKey, secret, new REST());
 Different interfaces:
 flickr.getPhotosInterface()
 flickr.getPeopleInterface()
 flickr.getContactsInterface()
 flickr.getLicensesInterface()
 flickr.getTagsInterface()
 …

12.  Init service:
Flickr flickr = new
Flickr("47422029b3aabee4aca6a5853eca74b6",
"ab7f2d30639a9828", new REST());
PhotosInterface pi =
flickr.getPhotosInterface();
SearchParameters sp = new
SearchParameters();
String []tabTag = {« cars »};
sp.setTags(tabTag);
PhotoList photoList = pi.search(sp, 50, 1);
Iterator it = photoList.iterator();
while (it.hasNext()) {
Photo photo = (Photo) it.next();
out.println("<img src='" +
photo.getThumbnailUrl() + "' />");

13.  URL API: Example: flickr.blogs.getList
 XML response
<blogs>
<blog id="73" name="Bloxus" url="http://remote.bloxus.com/" />
<blog id="74" name="Manila" url="http://test1.userland.com/" />
</blogs>
 JSON response
rsp = { "stat": "ok",
"blogs": {
"blog": [{ "id" : "73", "name" : "Bloxus", "url" : "..." }
{ "id" : "74", "name" : "Manila", "url" : "..." } ]
}
}
 URL API: Example
for (var i=0; i<rsp.blogs.blog.length; i++){
var blog = rsp.blogs.blog[i]
...
}

14.  API key and secret:
http://code.google.com/apis/youtube/dashboard
 REST interface:
http://www.youtube.com/api2_rest
 To request a response in JSON format, use the
alt=json parameter.
 Server side API: Java, .NET, PHP, python …
 Widget and players API (client side): javascript,
flash

15.  Import
import com.google.gdata.client.youtube.YouTubeService;
import com.google.gdata.util.ServiceException;
 Init service
YouTubeService myService =
new YouTubeService("the name of my app");
 Init search query:
YouTubeQuery query =
new YouTubeQuery(new URL(URL_VIDEOS_FEED));
 Appel au service:
VideoFeed videoFeed =
service.query(query, VideoFeed.class);
for (VideoEntry ve : videoFeed.getEntries()) {
...
}

16.  Parametrize query:
 search terms: query.setVideoQuery(searchTerms);
 Order: RELEVANCE, VIEW_COUNT, PUBLISHED, RATING :
query.setOrderBy(YouTubeQuery.OrderBy.RELEVANCE);
 Number of results: query.setMaxResults(count);
 Pagination: query.setStartIndex(start);
 include restricted content (excluded by default):
query.setIncludeRacy(true);
 Code example

17.  Basis:
// create a search control
var searchControl = new google.search.SearchControl(null);
// add in a full set of searchers
searchControl.addSearcher(new google.search.LocalSearch());
searchControl.addSearcher(new google.search.WebSearch());
searchControl.addSearcher(new google.search.VideoSearch());
searchControl.addSearcher(new google.search.BlogSearch());
searchControl.addSearcher(new google.search.NewsSearch());
searchControl.addSearcher(new google.search.ImageSearch());
searchControl.addSearcher(new google.search.BookSearch());
searchControl.addSearcher(new google.search.PatentSearch());
// tell the searcher to draw itself and tell it where to attach
// Note that an element must exist within the HTML document with
id "search_control"
searchControl.draw(document.getElementById("search_control"));

18.  SearcherControl Draw Modes:
 create a drawOptions object
var drawOptions = new google.search.DrawOptions();
 tell the searcher to draw itself in linear mode
drawOptions.setDrawMode(google.search.SearchControl.DRAW_MODE_LINEAR);
 tell the searcher to draw itself in linear mode
drawOptions.setDrawMode(google.search.SearchControl.DRAW_MODE_TABBED);
 decouple the "search form" from the set of search results
drawOptions.setSearchFormRoot(document.getElementById("id_dom_elem"));
 Display results :
searchControl.draw(element, drawOptions);

19.  Keeping a Search Result:
// establish a keep callback
searchControl.setOnKeepCallback(this, MyKeepHandler);
function MyKeepHandler(result) {
// clone the result html node
var node = result.html.cloneNode(true);
// attach it
var savedResults =
document.getElementById("saved_results");
savedResults.appendChild(node);
}

20. http://gmaps-
samples.googlecode.com/svn/trunk/demogallery.html

21.  Install facebook "Developper" application
to get API_Key and secret.
 Interface restful:
http://api.facebook.com/restserver.php?
v=1.0&api_key=YOUR_API_KEY&method=METHOD_NAME&sig=METHO
D_OPTIONS
 FacebookML: A meta language to develop
facebook apps (interpreted on facebook
servers)
 FQL: Facebook Query Language
 Server API: Php, java, .NET, etc;

22.  Plus maintenue par facebook:
Alternatives: http://code.google.com/p/facebook-java-api
 Authentification de l'application:
Facebook fb =
new Facebook(request, response, FB_API_KEY,
FB_SECRET_KEY);
fb.requireLogin("")
if(!face.isLogin()) return null; //can't access
application
FacebookRestClient fbrclient =
fb.getFacebookRestClient();
 Id utilisateur:
fbrclient.users_getLoggedInUser();

23.  Récupérer le nom et status de l'utilisateur courant (un peu compliqué,
mais bon…):
//fill the list of users
ArrayList<Long> user = new ArrayList<Long>();
//set of information required on users
EnumSet<ProfileField> fields =
EnumSet.of(com.facebook.api.ProfileField.NAME,
com.facebook.api.ProfileField.STATUS);
users.add(fbrclient.users_getLoggedInUser());
Document d = fbrclient.users_getInfo(users, fields);
String userName =
d.getElementsByTagName(com.facebook.api.ProfileField.NAME.fi
eldName)
.item(0).getTextContent();
String userName =
d.getElementsByTagName(com.facebook.api.ProfileField.NAME.fi
eldName)

24.  Informations sur les amis:
Document d = fbrclient.friends_get();
NodeList userIDNodes = d.getElementsByTagName("uid");
Collection<Integer> friends = new ArrayList<Integer>();
for (int i = 0; i < userIDNodes.getLength(); i++) {
Node node = userIDNodes.item(i);
Integer id = Integer.valueOf(node.getTextContent());
friends.add(id);
}
Document infos =
fbrclient.users_getInfo(users, fields);
//then we can iterate on the list of friends id and get the
information
for(Integer id : friends){
String fieldName =
infos.getElementsByTagName(...).item(i).getTextContent();
//etc.
}

25.  All google apps:
http://code.google.com/more
 Open social
http://code.google.com/apis/opensocial/
 Maps: http://code.google.com/apis/maps/
 Etc.
 Delicious: http://delicious.com/help/api
 Digg: http://apidoc.digg.com/
 Technorati:
http://technorati.com/developers/api/
 And most of web 2.0 platforms propose
access to their data through APIs!!!

26. Build a search engine that search on
different web 2.0 services and propose
differents médias:
 Photos with flickr
 Video with youtube
 People and social features with facebook
 And whatever you want with web 2.0
APIs.