Devoxx Java Social and Agorava

Java Social JSR,
It’s Alive

Antoine Sabot-Durand
Java EE Expert, Architect
Ippon Technologies
@antoine_sd

Werner Keil
Build Manager, DevOps Expert,
Agile Coach
Maersk Line
@wernerkeil
mardi 13 novembre 12

Antoine Sabot-Durand
• Java EE expert at Ippon Technologies
• Architect and Tech consultant
• 16 years in IT
• Java & OSS :
• Agorava technical leader
• Apache Deltaspike Commiter
• Member of l’EG CDI 1.1(JSR 346)
• @antoine_sd

2


Werner Keil - Bio
• Consultant – Coach

• Creative Cosmopolitan
• Open Source Evangelist
• Software Architect
• Java Godfather
• JCP Executive Committee Member
• Eclipse UOMo Project Lead
• DevOps Guy

3


Agenda
• Episode I : History – JSR 357 Rise and Fall
• The precursors
• From Seam Social to JSR 357
• What went Wrong?
• Episode II : Standards in Social Media
• The standards part
• The non standard part
• So what would be a Java Standard for Social Media ?

4


Agenda (2)
• Espisode III : The Agorava Project
• Agorava Demo
• From JSR 357 to Agorava
• Agorava architecture
• Extending Agorava
• Related JSR : Security & identity
• Differences from other APIs and Frameworks
• Episode IV: Agorava, the technical parts
• Jackson Mapping Mixin
• CDI in Agorava 0.5
• JsonSchema2Pojo
• JAX-RS 2.0 client Framework in Agorava 1.0
• Episode V : Demo and Q&A 5


Episode I
JSR 357 Rise and Fall


Before JSR 357 (Java Social)

7


Twitter4j
• Twitter4J is an unofﬁcial Java library for the Twitter API.
With Twitter4J, you can easily integrate your Java application with Twitter.

• Its author, Yusuke Yamamoto used to work at Twitter.
While he did, he was brieﬂy meant to represent Twitter in the Social JSR
EG.

• It’s light and based on Java 1.4 to be integrated in mobile app for instance

8


Scribe Java
• Scribe is java framework that provides basic OAuth function

• It also contains conﬁguration for a lot of Social Media

• Only one dependency on Apache Common Codec

• At the heart of Agorava 0.5

9


DaliCore – CMS
• More than a CMS → DaliCore
• Adds functionality common to users, content and permissions on top of
Java EE 6.
• Focus on Users and Permissions.
• In about every project that uses DaliCore, users should be able to login
with existing credentials (Facebook, Twitter, Google Connect,...)
• Dali modules extend DaliCore

10


Spring Social
• Spring social that inspired Seam Social and Agorava and is more mature

• Spring Social module were used to create ﬁrst agorava modules (thanks
to OSS and ASL2)

• But it’s Spring only module....

11


And then the JSR 357 was proposed
• In march 2012 on Werner Keil initiative, Java Social was submitted to the
JCP to become a JSR

• It proposed to standardized access to Social Media in Java

• It was voted down by 8 votes against 5

12


What went Wrong? (Feedback from vote)

13


Too Broad ?

Maybe...
14


Too Soon?

Lack of real POC... 15


It can’t be standardized?

FALSE
16


Episode II
Standards in Social Media


Standard part in social media
• All social medias use REST as transmission protocol

• Most of them transmit data in JSON format and some in XML

• Identiﬁcation & Authentication are almost always based on OAuth
protocol

18


REST
• REpresentational State Transfer : Requests about resource representation
(customer, book, order)

• REST is based on low level HTTP concepts

• Each resource has a unique identiﬁer (an URI). 4 HTTP verbs can be
applied to a uri : GET, POST, PUT, DELETE

• Java has a standard to deal with REST: JAX-RS. Version 1.0 doesn’t
provide client API yet. JAX-RS 2.0 will provide one
19


JSON
Javascript Object Notation : This data
1: {
2: "firstName": "John", format comes from Javascript. It became a
3:
4:
"lastName" : "Smith",
"age" : 25, standard for online services including Social
5:
6:
"address" :
{ Media.
7: "streetAddress": "21 2nd Street",
8: "city" : "New York",
9: "state" : "NY",
10: "postalCode" : "10021"
11: },
12: "phoneNumber":
13: [
14: {
15: "type" : "home",
16: "number": "212 555-1234"
17: },
18: {
19: "type" : "fax",
20: "number": "646 555-4567"
21: }
22: ]
23: }

20


OAuth
• OAuth is a protocol to delegate rights for an application to act on the
behalf of an user who granted its rights without giving awayher login /
password
• Developped by Twitter, Magnolia and Google, it was made standard by
IETF in april 2010 under RFC 5849
• Version 2.0, simpler to use but often citicised by its too many
implementation s was standardized in October 2012 under RFC 6749
and 6750. It’s already used by many actors (Facebook, Google, Microsoft)
• All social Media are based on OAuth 1.0a or 2.0.
• To use OAuth, one has to create an application on the targeted service
to have an entry point for consumer 21


OAuth has 3 step
• Creating an application in the OAuth Social Media service

• Initialization : the right granting phase also called the OAuth Dance. At
the end of the dance we obtain an access token (formed by a public and
secret part) use in next step

• Signature : each request is signed with access token and token
identifying the OAuth application that was granted the rights

22


OAuth Step 1 : Create an application

23


OAuth : application settings

24


The OAuth 1.0a «Dance»
Social Media Service
(where OAuth application is declared)

user

Consuming service server 25



user

1

client asks for a
resource on the
consuming service




user
Consuming service ask a
1
request token tot he Social
2 Media (using OAuth
application keys). It also send
a callback url
client asks for a
resource on the
consuming service




token is returned by SM
user 3
1
a callback url
client asks for a
resource on the
consuming service




Consuming
service 4

redirect user
on the social
media login token is returned by SM
page user 3
1
a callback url
client asks for a
resource on the
consuming service



Once authenticated, social media (where OAuth application is declared)
redirects user on call back url with a
veriﬁcation code
Consuming
service 4

redirect user 5

on the social
page user 3
1
a callback url
client asks for a
resource on the
consuming service



veriﬁcation code
Consuming
service 4

redirect user 5

on the social
page user 3
1
6 application keys). It also send
a callback url
client asks for a
resource on the with the code and request token
consuming service consuming service request an access
token



veriﬁcation code
Consuming Social media returns Access token
service 4

redirect user 5

on the social
7
page user 3
1
6 application keys). It also send
a callback url
client asks for a
resource on the with the code and request token
consuming service consuming service request an access
token



The OAuth 2.0 «Dance» now in SSL

user




user

1

client asks for a
resource on the
consuming service
SSL is mandatory



Consuming
service
redirect user 2

on the social
media login
page user

1

client asks for a
resource on the
consuming service
SSL is mandatory


veriﬁcation code
Consuming
service
redirect user 2 3

on the social
media login
page user

1

client asks for a
resource on the
consuming service
SSL is mandatory


veriﬁcation code
Consuming
service
redirect user 2 3

on the social
media login
page user

1

4

client asks for a with the code and request token
resource on the consuming service request an access
consuming service token
SSL is mandatory


veriﬁcation code
Consuming Social media returns Access token
service
redirect user 2 3

on the social
5
media login
page user

1

4

client asks for a with the code and request token
resource on the consuming service request an access
consuming service token
SSL is mandatory


OAuth Signature : original request

27


OAuth Signature : original request

POST /1/statuses/update.json?include_entities=true HTTP/1.1
Accept: */*
Connection: close
User-Agent: OAuth gem v0.4.4
Content-Type: application/x-www-form-urlencoded
Content-Length: 76
Host: api.twitter.com

status=Hello%20Ladies%20%2b%20Gentlemen%2c%20a%20signed%20OAuth
%20request%21

27


OAuth Signature : request & OAuth params

28


OAuth Signature : request & OAuth params

status Hello Ladies + Gentlemen, a signed OAuth request!
include_entities true
oauth_consumer_key xvz1evFS4wEEPTGEFPHBog
oauth_nonce kYjzVBB8Y0ZFabxSWbWovY3uYSQ2pTgmZeNu2VS4cg
oauth_signature_method HMAC-SHA1
oauth_timestamp 1318622958
oauth_token 370773112-GmHxMAgYyLbNEtIKZeRNFsMKPR9EyMZeS9weJAEb
oauth_version 1.0

28


OAuth Signature : parameter string

29


OAuth Signature : parameter string

include_entities=true&oauth_consumer_key=xvz1evFS4wEEPTGEFP
HBog&oauth_nonce=kYjzVBB8Y0ZFabxSWbWovY3uYSQ2pTgmZeNu2VS4cg
&oauth_signature_method=HMAC-
SHA1&oauth_timestamp=1318622958&oauth_token=370773112-
GmHxMAgYyLbNEtIKZeRNFsMKPR9EyMZeS9weJAEb&oauth_version=1.0&
status=Hello%20Ladies%20%2B%20Gentlemen%2C%20a%20signed
%20OAuth%20request%21

29


OAuth Signature : Base String

30


OAuth Signature : Base String

POST&https%3A%2F%2Fapi.twitter.com%2F1%2Fstatuses
%2Fupdate.json&include_entities%3Dtrue%26oauth_consumer_key
%3Dxvz1evFS4wEEPTGEFPHBog%26oauth_nonce
%3DkYjzVBB8Y0ZFabxSWbWovY3uYSQ2pTgmZeNu2VS4cg
%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp
%3D1318622958%26oauth_token%3D370773112-
GmHxMAgYyLbNEtIKZeRNFsMKPR9EyMZeS9weJAEb%26oauth_version
%3D1.0%26status%3DHello%2520Ladies%2520%252B%2520Gentlemen
%252C%2520a%2520signed%2520OAuth%2520request%2521

30


OAuth Signing key

31


OAuth Signing key

Application consumer key secret part

VQ5CZHG4qUoAkUUmckPn4iN4yyjBKcORTW0wnok4r1k&
LswwdoUaIvS8ltyTt5jkRh4J50vUPVVHtR2YPi5kE

Access Token secret part

31


OAuth Signature : Signed request

32


OAuth Signature : Signed request
POST /1/statuses/update.json?include_entities=true HTTP/1.1
Accept: */*
Connection: close
User-Agent: OAuth gem v0.4.4
Content-Type: application/x-www-form-urlencoded
Authorization:
OAuth oauth_consumer_key="xvz1evFS4wEEPTGEFPHBog",
oauth_nonce="kYjzVBB8Y0ZFabxSWbWovY3uYSQ2pTgmZeNu2VS4cg",
oauth_signature="tnnArxj06cWHq44gCs1OSKk%2FjLY%3D",
oauth_signature_method="HMAC-SHA1",
oauth_timestamp="1318622958",
oauth_token="370773112-GmHxMAgYyLbNEtIKZeRNFsMKPR9EyMZeS9weJAEb",
oauth_version="1.0"
Content-Length: 76
Host: api.twitter.com

status=Hello%20Ladies%20%2b%20Gentlemen%2c%20a%20signed%20OAuth%20request%21
32


The non Standard parts
• Non standard identity management or any other API across Social Media

• More than that. There is no Social Media that Guarantee :

• Its API won’t change for a given period

• backward compatibility when its API change

33


So what would be a standard for Social ?
• A basic heart providing basic services :
• OAuth and Rest request
• Multi Social Media connexions
• Polymorphic services to enforce standard on social Media
• Connector deﬁnition for Social module

• So this standard would be a kind Java Social Connector deﬁnition
standard

34


Socializer Demo


Episode III
Agorava Project


From JSR 357 to Agorava
• Before Agorava there was Seam Social part of Seam 3 JBoss project
• In begining of 2012, Seam was stopped to be merged in Apache
DeltaSpike
• Agorava was born mainly from Seam Social after JSR 357 attempt
• One of it’s goals is to be the missing POC
for a new Java Social JSR

37


Linked concept Security and Identity
• Identity, Privacy and Trust
• Identity attributes are properties of a digital subject
• A digital subject is a digital representation of an entity that is an actor or
target of a digital operation.
• Privacy is the degree to which the availability of an entity’s identity
attributes can be controlled
• Trust is an evaluation of the reliability of a representation of a digital
subject
• An identity is a set of identity attributes that distinguish an entity

38


Identity for Social Media
• Java Identity API (JSR 351) goals for Social Media
• Attribute Service composed of attribute providers
• specification will define contracts to facilitate repository integrations
by third parties.
• Reference Implementation will provide some specific integrations
including those provided by contributors to Open Source project;
Facebook, Twitter, and LinkedIn will be among the identity repositories
considered for integration within the reference integration, as will their
associated programming interfaces and protocols, including Facebook
Connect, Google-ID and OAuth 2.0.
39


Facebook JSR 351 Example – Agent
@Named("Facebook")
public class FacebookRepositoryAgent implements RepositoryAgent {
public AttributeRepository getAttributeRepository(String repositoryName) {
TableIdentifier tID = null;
AttributeRepository rvalue = null;
try {
tID = FacebookTableID.valueOf(repositoryName);
rvalue = repositoryTable.get(tID);
} catch (IllegalArgumentException iae) {
}
if (rvalue == null) {
rvalue = new FacebookAttributeRepository(new
RepositoryDescriptor(FacebookRepositoryAgent.class,tID.name()));
repositoryTable.put(tID,rvalue);
}
return rvalue;
} 56


Facebook JSR 351 Example – Repository
public class FacebookAttributeRepository implements AttributeRepository {
private RepositoryDescriptor _repositoryDescriptor;
private ProviderLookupContext _context; FacebookLookupService _lookupService;

public FacebookAttributeRepository(RepositoryDescriptor descriptor) {
_repositoryDescriptor = descriptor;
_context = new ProviderLookupContext(descriptor);
_lookupService = new FacebookLookupService(this);
}
public RepositoryDescriptor getRepositoryDescriptor() {
return _repositoryDescriptor;
}
[…]
public IDPredicate and(IDPredicate ... predicates) {
return new FacebookPredicate(_context, IDBooleanOperator.and, predicates);
}
57


Facebook JSR 351 Example – Connect
JSONObject graphValues = getResponseValues(graphResponse);
user = (String) graphValues.get(userPropertyName);
Iterator<String> it = graphValues.keys();
while (it.hasNext()) {
String key = it.next();
final URI id = new URI(userInfoEndpoint + "/" + key);
final Collection<String> names = new ArrayList<String>();
final Object value = graphValues.get(key);
final IDAttributeValue attributeValue = new IDAttributeValue() {
public Serializable getValue() {
return (Serializable) value;
}
public Collection getValues() {
return Collections.EMPTY_LIST;
}
};
58
}


Agorava Goals
• Provides generics services
across different Social Media
(identiﬁcation, Post, etc...)
• Dynamic discovery of Social
Media modules (core detect
what modules are available at
startup)
• Managing multiple Social Media
connection at the same time
• Provides high level services
(and binding) to interact with
Social Media 43


Agorava 0.5 Macro architecture
• Agorava core is the «smart
Twitter
Module
LinkedIn
Module
Facebook
Module
Social Media X
module
part» of the framework
• Modules are mainly REST
Agorava Core API and JSON mapping
CDI impl Guice impl Spring impl • Today Agorava has a CDI
implementation only
@Inject impl
• On the roadmap we plan to
Java SE Impl
provide :
• full Java SE support
API
• JSR 330 (Guice and/or
Spring) support 44


Agorava core API architecture
«interface»
api.rest.
«interface» «interface»
api.oauth. api.oauth.
RestRequest
OAuthProvider OAuthRequest
+send()
+getRequestToken() +addOAuthParameter(String, String) +addHeader(String, String)
+getAccessToken(OAuthToken, String) +getOauthParameters() +addBodyParameter(String, String)
+signRequest(OAuthToken, OAuthRequest) +addBodyParameters(Map)
+getVersion() +addQuerystringParameter(String, String)
+getAuthorizationUrl(OAuthToken) +addPayload(String)
+requestFactory(RestVerb, String) +getQueryStringParams()
+tokenFactory(String, String) +getBodyParams()
+getUrl()
+getSanitizedUrl()
«interface» «interface» +getBodyContents()
+getVerb()
OAuthAppSettings OAuthService +getHeaders()
«interface»
api.rest. +setConnectTimeout(int, TimeUnit)
+getApiKey() +getAccessToken() RestService +setReadTimeout(int, TimeUnit)
+getApiSecret() +getAuthorizationUrl() +getCompleteUrl()
+getCallback() +getVerifier() +addPayload(byte[n])
+isConnected() +getCharset()
+getScope() +initAccessToken()
+getType() +setCharset(String)
+getSocialMediaName() +sendSignedRequest(RestVerb, String)
+get(String, Class) +setConnectionKeepAlive(boolean)
+sendSignedRequest(RestVerb, String, Map)
+get(String, Class, Object[n])
+sendSignedRequest(RestVerb, String, String, Object)
+post(String, Map, Class)
+setVerifier(String)
+post(String, Object, Object[n])
+setAccessToken(String, String) «interface»
+put(String, Object, Object[n])
+setAccessToken(OAuthToken) api.oauth.
+delete(String) api.
OAuthToken
+sendSignedXmlRequest(RestVerb, String, String) UserProfile
+setRequestHeader(Map)
+getSession()
cdi. +sendSignedRequest(OAuthRequest)
AbstractSocialMediaApi +getToken()
+get(String, Class, boolean) +getFullName()
+getSecret()
+getProfileImageUrl()
+buildUri(String, String, String) +equals(Object)
«interface»
+buildUri(String, Map) api.
«interface»
+buildUri(String) SocialMediaApiHub api.oauth.
+buildUri(String, Object) OAuthSession
+getMyProfile()
+resetConnection() +getRequestToken()
+isConnected() +setRequestToken(OAuthToken)
+getVerifierParamName() +getAccessToken()
«interface» +getSocialMediaName() +setAccessToken(OAuthToken)
api.oauth.
+getVerifier()
OAuthServiceAware +setVerifier(String)
+setUserProfile(UserProfile)
+getService() +getUserProfile() 45
+getSession() +getServiceQualifier()
+isConnected()
+getName()


Main classes
«interface»
api.oauth. api.
api.oauth. cdi.
OAuthProvider SocialMediaApiHub OAuthAppSettings AbstractSocialMediaApi

+getRequestToken() +getMyProfile()
+getApiKey() +buildUri(String, String, String)
+getAccessToken(OAuthToken, String) +resetConnection()
+getApiSecret() +buildUri(String, Map)
+signRequest(OAuthToken, OAuthRequest) +isConnected()
+getCallback() +buildUri(String)
+getVersion() +getVerifierParamName()
+getScope() +buildUri(String, Object)
+getAuthorizationUrl(OAuthToken) +getSocialMediaName()
+getSocialMediaName()
+requestFactory(RestVerb, String)
+tokenFactory(String, String)

OAuthService OAuthSession

+getAccessToken() +getRequestToken()
+getAuthorizationUrl() +setRequestToken(OAuthToken)
+getVerifier() +getAccessToken()
+initAccessToken() +setAccessToken(OAuthToken)
+sendSignedRequest(RestVerb, String) +getVerifier()
+sendSignedRequest(RestVerb, String, Map) +setVerifier(String)
+sendSignedRequest(RestVerb, String, String, Object) +setUserProfile(UserProfile)
+setVerifier(String) +getUserProfile()
+setAccessToken(String, String) +getServiceQualifier()
+setAccessToken(OAuthToken) +isConnected()
+sendSignedXmlRequest(RestVerb, String, String) +getName()
+getSession()
+sendSignedRequest(OAuthRequest) 46
+get(String, Class, boolean)


OAuth configuration
public interface OAuthAppSettings { • OAuthAppSettings contains
needed infos to start the OAuth
public String getApiKey();
Dance :
public String getApiSecret();
•Public and private keys of OAuth
public String getCallback();
application

public String getScope();
•Callback URL
•OAuth 2.0 scope
public String getSocialMediaName();
•Name of the Social Media to
} which these settings are related

47


OAuth support
public interface OAuthProvider { • OAuthProvider provides
public OAuthToken getRequestToken(); OAuth support. Its
public OAuthToken getAccessToken(OAuthToken tok, String ver); implementation uses
public void signRequest(OAuthToken tok, OAuthRequest req);
OAuthAppSettings to get
initatilized
•
public String getVersion();
There one can :
•
public String getAuthorizationUrl(OAuthToken requestToken);
Create a RequestToken
public OAuthRequest requestFactory(RestVerb v, String uri);

public OAuthToken tokenFactory(String token, String secret);
• Get the URL to start
connexion
•
}
Get the Acces Token
• Create OAuth signature 48


Rest calls with OAuthService
public interface OAuthService extends RestService {
• OAuthService uses
public OAuthToken getAccessToken();
OAuthProvider to create and
public String getAuthorizationUrl();

public String getVerifier();
sign requests. It provides
public void initAccessToken(); higher level services :
public RestResponse sendSignedRequest(RestVerb verb, String uri);

public RestResponse sendSignedRequest(RestVerb verb, String uri, Map<String, ?> params); • Integration of user OAuth
public RestResponse sendSignedRequest(RestVerb verb, String uri, String key, Object value); session
public void setVerifier(String verifierStr);

public void setAccessToken(String token, String secret); • Management of OAuth life
public void setAccessToken(OAuthToken token); cycle
public RestResponse sendSignedXmlRequest(RestVerb verb, String uri, String payload);

public OAuthSession getSession(); • Sending simple Rest Request

}
public RestResponse sendSignedRequest(OAuthRequest request);

<T> T get(String uri, Class<T> clazz, boolean signed);
• Sending signed Rest Request
49


High level API root : AbstractSocialMediaApi

• AbstractSocialMediaApi is
the root for each family of
API in a given social media
module

• Some services provides
more than ten API families
(for instance Twitter)
• So we need a concept to
gather these families 50


API families Hubs with SocialMediaApiHub
public interface SocialMediaApiHub extends
OAuthServiceAware, Serializable {
• Hubs are here to :
•Provide a gathering class
public UserProfile getMyProfile(); for all API families of a
public void resetConnection();
given service

public boolean isConnected();
•Be the entry point of
generic functionalities
public String getVerifierParamName(); across different Social
Media
public String getSocialMediaName();
• They also are the entry
} point of Social Media
conﬁguration 51


OAuthSession contains user specific infos

•
public interface OAuthSession extends Serializable {
OAuthSession contains data
public OAuthToken getRequestToken();
to handle the user part of an
public void setRequestToken(OAuthToken requestToken);
OAuth connexion :
public OAuthToken getAccessToken();
• RequestToken
•
public void setAccessToken(OAuthToken accessToken);
Veriﬁer
•
public String getVerifier();
And last but not least
public void setVerifier(String verifier);
AccessToken
public void setUserProfile(UserProfile userProfile);
• OAuthSession keeps alos
public UserProfile getUserProfile();
track of connected user
public Annotation getServiceQualifier(); identity
public boolean isConnected(); 52
}


Bootstraping Twitter in CDI Impl
@Twitter Thanks to Generic Beans extension this
@ApplicationScoped
@OAuthApplication producer create 4 beans with different
@Produces
public SocialMediaApiHub OAuthSettinsProducer(TwitterServicesHub service) { scopes.
}
return service;
By default OAuth app settings are read
in agorava.properties file
@Twitter
@ApplicationScoped @Twitter
@SessionScoped
«interface»
@Twitter
@Twitter api.oauth.
@ApplicationScoped
OAuthService
@ApplicationScoped «interface»
api.oauth.
+getAccessToken()
OAuthSession
+getAuthorizationUrl()
+getVerifier()
«interface»
+initAccessToken() +getRequestToken()
api.oauth.
+sendSignedRequest(RestVerb, String) +setRequestToken(OAuthToken)
«interface» OAuthProvider
+sendSignedRequest(RestVerb, String, Map) +getAccessToken()
api.
+sendSignedRequest(RestVerb, String, String, Object) +setAccessToken(OAuthToken)
SocialMediaApiHub
+setVerifier(String) +getVerifier() +getRequestToken()
+setAccessToken(String, String) +setVerifier(String) +getAccessToken(OAuthToken, String)
+getMyProfile() +setAccessToken(OAuthToken) +setUserProfile(UserProfile) +signRequest(OAuthToken, OAuthRequest)
+resetConnection() +sendSignedXmlRequest(RestVerb, String, String) +getUserProfile() +getVersion()
+isConnected() +getSession() +getServiceQualifier() +getAuthorizationUrl(OAuthToken)
+getVerifierParamName() +sendSignedRequest(OAuthRequest) +isConnected() +requestFactory(RestVerb, String)
+getSocialMediaName() +get(String, Class, boolean) +getName() +tokenFactory(String, String)
53


Create a new Agorava module
• To create a new module for Agorava 0.5, you have to :
• Create a Qualifier (annotation) tagued with @ServiceRelated meta
annotation
• Create a low level API class containing basic endpoints to the new Social
service. The class should use the same name as qualifier
• Extend AbstractSocialMediaApi to create the root class for all API
families of the new Social Media
• Extend AbstractSocialMediaApiHub to gather Api families and
implements generic services
• At minima create Service class to deal with user profile in the new
service 54


Episode IV
Technologies in Agorava


Jackson


Jackson
• JSON to Pojo binding

• A JAX-B like solution for JSON

• Works with JAX-B anotations

• Provides also Json parsing tools

• Provides an elegant solution : the Mixin to conﬁgure mapping outside of
the pojo 57


Mixin Example
public class Trend {
private final String name;

private final String query;

public Trend(String name, String query) { @JsonIgnoreProperties(ignoreUnknown = true)
this.name = name; abstract class TrendMixin {
this.query = query;
} @JsonCreator
TrendMixin(@JsonProperty("name") String name,
public String getName() { @JsonProperty("query") String query) {
return name; }
}
}
public String getQuery() {
return query;
}

}
58


Module configuration is needed to use mixin
class TwitterModule extends SimpleModule {
public TwitterModule() {
super("TwitterModule", new Version(1, 0, 0, null));
}
@Override
public void setupModule(SetupContext context) {
context.setMixInAnnotations(TwitterProfile.class, TwitterProfileMixin.class);
context.setMixInAnnotations(SavedSearch.class, SavedSearchMixin.class);
context.setMixInAnnotations(Trend.class, TrendMixin.class);
}
}

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new TwitterModule);
59


Simple dependency injection
@ApplicationScoped
public class JsonMapperJackson implements JsonMapper {
...
}

public class OAuthServiceImpl implements OAuthService {

...

@Inject
protected JsonMapper jsonService;

...
} 61


Qualified Injection
@Qualifier
@ServiceRelated
@Target({TYPE, METHOD, PARAMETER, FIELD})
@Retention(RUNTIME)
@Documented
public @interface Twitter {
}

public abstract class TwitterBaseService extends AbstractSocialMediaApi {
...
@Inject
@Twitter
private OAuthService service;
...
}
62


Producer
@ApplicationScoped
public class JsonMapperJackson implements JsonMapper {

@Produces
private final ObjectMapper objectMapper = new ObjectMapper();
...
}

public class GraphApiImpl extends FacebookBaseService
implements GraphApi {

@Inject
private ObjectMapper objectMapper;
...
}
63


Programatic injection

@Inject
@Any
private Instance<OAuthProvider> providers;
...
protected Annotation qualifier;
...
private OAuthProvider getProvider() {
return providers.select(getQualifier()).get();
}
...
}

64


Programmatic injection for Mixin
@Twitter @ServiceX
class TwitterModule extends SimpleModule { class ServiceXModule extends SimpleModule {
... ...
} }

@Facebook
class FacebookModule extends SimpleModule {
...
}

@Inject
@Any
protected Instance<Module> moduleInstances;
...
@PostConstruct
protected void init() {
for (Module module : moduleInstances) {
registerModule(module);
}
} 65


Context & context Mixup
@SessionScoped
public class MultiSessionManagerImpl implements MultiSessionManager, Serializable {

@Produces @Named @Current
private OAuthSession currentSession;

public String initNewSession(String servType) {
Annotation qualifier = getServicesToQualifier().get(servType);
setCurrentSession(new OAuthSessionImpl(qualifier));
return getCurrentService().getAuthorizationUrl();
}
}

@ApplicationScoped

@Inject
@Any
protected Instance<OAuthSession> sessionInstances;
... 66
}


Decorator
@Decorator
public abstract class TwitterTLServiceDecorator implements TwitterTimelineService {

@Inject
@Delegate
@Any
private TwitterTimelineService delegate;

@Override
public Tweet updateStatus(String status) {
System.out.println("*** In Decorator ***");
delegate.updateStatus(status + "decorated" );
}
}

67


Events
...
@Inject @Any
private Event<OAuthComplete> completeEventProducer;
...
public synchronized void initAccessToken() {
session.setAccessToken(getProvider().getAccessToken(getRequestToken(), session.getVerifier()));
Event<OAuthComplete> event = completeEventProducer.select(getQualifier());
event.fire(new OAuthComplete(SocialEvent.Status.SUCCESS, "", session));
}
}

public class FacebookServicesHub extends AbstractSocialMediaApiHub {
...

@Inject
Instance<FacebookBaseService> services;
...
public void initMyProfile(@Observes @Facebook OAuthComplete oauthComplete) {
if (oauthComplete.getStatus() == Status.SUCCESS)
oauthComplete.getEventData().setUserProfile(services.select(UserServiceImpl.class).get().getUserProfile());
}
...
}

68


CDI extensions


CDI Extensions why ?
• An extension allows to
• Create beans or injection
points
• modify beans or injection
points
• Cancel beans creation
• More generally to analyse all
beans and change them
before the application is
launch
70


Understanding extensions
• Once the application is
running, bean manager is
immutable (no dynamic bean
in CDI)

• Extensions will be launch
when the application is
launch

• Extensions are also Beans
71


CDI Lifecycle

Deploy Process Process Before Undeploy
Application Beans Producers Shutdown Application

Process
Before Bean Process Application
Observer
Discovery Injection Taget Running
Methods

After
Scan Process After Bean
Deployment
Archive Anotated Types Discovery
Validation
72


To create an extension

• Create a class which implements
Extension
• Add one or more method that Observes
CDI lifecycle steps to modify Bean
Manager content
• Add this ﬁle in classpath
META-INF/services/javax.enterprise.inject.spi.Extension

in which you add qualiﬁed name of the
extension class

73


Simple Example : @Veto

<X> void processAnnotatedType(@Observes final ProcessAnnotatedType<X> pat, BeanManager beanManager) {
        final AnnotatedType<X> annotatedType = pat.getAnnotatedType();
        final Class<X> javaClass = annotatedType.getJavaClass();
        final Package pkg = javaClass.getPackage();

        // Support for @Veto
        if (annotatedType.isAnnotationPresent(Veto.class) ||
(pkg != null && pkg.isAnnotationPresent(Veto.class))) {
            pat.veto();
            log.info("Preventing " + javaClass + " from being installed as bean due to @Veto annotation");
            return;
        }
}

74


New technologies in version 1.0
• JAX-RS 2.0 client framework
• Development has just started
• It will deprecated Java Scribe in Agorava
• OAuth ﬁlters has to be written for this client

• Json 2 pojo schema
• An easy way to generate pojo from Json
• Demo

75


Major API Evolution in version 1.0
public interface HasTimeline {
public interface HasUpdate {
public List<String> getTimeLine();
public boolean sendUpdate(String message);
public List<String> getTimeLine(Date from, Date to);
}
public List<String> getTimeLine(String fromId);

}

public class FacebookServicesHub extends AbstractSocialMediaApiHub implements HasUpdate, HasTimeline

@Inject
@Any
Instance<HasUpdate> updatables;
...
for (HasUpdate updatable : updatables) {
updatable.sendUpdate(msg);
76
}


Links
• Agorava Project:
http://agorava.org
• Follow us
http://twitter.com/agoravaproj
• Fork Agorava
http://github.com/agorava


Links
• DaliCore:
http://java.net/projects/dalicore/
• Oracle SocialLink:
http://java.net/projects/sociallink
• JSR 351 Identity API:
http://java.net/projects/identity-api-spec

• Nobis JSR 351 RI:
http://java.net/projects/nobis/


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