This slides give you an overview of the technical challgens that Java EE application servers have faced to reinvent themselves. From monolithic to jigsaw puzzles, app servers are not the burden developpers use to use anymore

1. Are application servers still
fascinating for developers ?
by antonio goncalves
@agoncal

2. Antonio Goncalves
●
Freelance software architect
●
Author (Java EE 5 and Java EE 6)
●
JCP expert member (Java EE 6, Java EE 7)
●
Co-leader of the Paris JUG
●
Les Cast Codeurs podcast
● Java Champion
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3. Co-creator of Devoxx France
●
Little brother of Devoxx (Belgium)
●
3 days conference (18th to 20th April 2012)
●
140 talks (75% in French)
●
In Paris
●
Cheap (450€)
● www.devoxx.fr
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4. Why am I talking here today
●
Former BEA employee
●
Started working with J2EE in 1998
●
With Weblogic 3.x
●
Java EE 6 / 7 Expert Member
●
Has used/played with most app servers
● Blogs about app servers
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5. « Application server »
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6. Wikipedia
« Server which provides
software applications with services»

7. Gartner
« Server that acts as a container for
applications' business logic...
and brings services »

8. Server and services
●
Server ●
Services
● « Program running to ● Security
serve the requests of ● Transaction
other programs »
● Load balancing
● Application server
● Distribution
● Database server
● Management
● Communication server
● Performance
● File server
● ...
● Fax server
● ...
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9. We use application servers not to
reinvent the wheel
(i.e the technical services)

10. « Application » server
●
Market dominated by
● Java
● .Net
●
Proprietary
●
Other programming models
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11. Let's focus on Java
Java EE 6
Web Profile 6
Servlet
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12. Web profile
●
Java EE 6
● 28 specifications
● Web profile
● 12 specifications
●
Other profiles will come
●
Brings modularity
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13. Modularity
●
OSGi / Modules / What ever
● Java modules in Java SE 8 / Java EE 8 ?
● App servers become jigsaw puzzles
●
Only startup needed modules
● Faster
●
Lighter
●
Time is changing
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14. History
JPE J2EE 1.2 J2EE 1.3 J2EE 1.4 Java EE 5 Java EE 6 Java EE 7
1995 May 1998 Dec 1999 Sept 2001 Nov 2003 May 2006 Dec 2009 Mar 2013
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15. Startup time of JBoss
Using a Windows XP virtual machine (Virtual Box)
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16. Startup time of other servers
Using a Windows XP virtual machine (Virtual Box)
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17. Industrial strengh
●
App servers implement the same specs
●
They all do the same basic stuff...
●
… so they must find a differentiator
● Startup time
● Memory footprint
● Administration
● Add ons
● Clustering
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18. Money, get away
●
Why is the app server battle so tough ?
●
*Because there is money involved :
● 2010 : app server market = $3.2 billion
● 9% growth per year
● 2015 : reaching $5 billion
(*)Gartner 2010
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19. Magic quadrant - Sep 2011
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20. Magic quadrant - Sep 2011
● Leaders
● Oracle
● IBM
● RedHat
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21. Magic quadrant - Sep 2011
● Visionary
● Resin
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22. Future<App Server>
●
« *In the next 5 years most app servers will be
extended for cloud computing purposes »
●
Elastic resource allocation
●
Dynamic clustering
●
Horizontal scaling
●
Multitenancy (Java EE 7)
(*)Gartner 2011
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23. Let's quickly have a look at some
“new” application servers

24. WebSphere Liberty 8.5

25. Webs.... fear
●
Ops love it
●
Devs hate it
● … and IBM wants us to love it now
●
OGSi
● Simple, Lightweight, Fast
●
Liberty Profile (not the web profile)
● No EJB Lite, no CDI
●
Free for development
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26. Composable runtime
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27. WAS 8.5 Licensing
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28. Demo

29. TomEE 1.0

30. TomEE
●
Based on Tomcat
●
… everybody knows Tomcat
●
Web Profile
●
Passed the TCK
●
TomEE + (web profile + JAX-RS / JAX-WS / JMS)
● Everything is free
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31. What's in
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32. Demo

33. Resin 4.x

34. Resin
●
Created in 1999 (web server)
●
First web profile certified in 2011
●
4.7 millions web sites hosted on Resin
● Mostly in finance
● “Visionary” on Gartner Magic Quadrant
●
Resin open source (free)
●
Resin professional
● Commercial license
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35. Inside Resin
●
Based on CanDI
●
Quercus (PHP)
●
Watchdog
●
Cloud ready (dynamic clustering)
●
Remote EJBs use Hessian (instead of RMI)
● Multitenancy
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36. Demo

37. And now, the developers point of
view

38. How is it to use these servers on a
day to day basis ?

39. Yaps Petstore
●
Inspired from Sun Petstore Blueprint
●
Java EE 6 - Web profile (packaged in a war)
●
No external dependencies
●
Portable (well, kind of)
● GlassFish 3.x / JBoss 7.x / TomEE / Resin / ...
●
JPA 2.0 / EJB 3.1 Lite / CDI 1.0 / JSF 2.0 / Bean
Validation 1.0 / JAX-RS 1.1
● https://github.com/agoncal/agoncal-
application-petstore-ee6
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40. Demo of the Yaps Petstore
with GlassFish 3.x

41. Developing / Debugging
●
Good old “develop/package/deploy/start”
● Event if app servers start quickly
● Takes too much time
●
JRebel...
● … is your friend
● Hot deployment
● Reload classes
● Updates web resources
● Saves you time
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42. Demo with JRebel

43. Testing
●
Unit Tests
● Mock container services
● Integration Tests
● WYTIWYR (What You Test Is What You Run)
● Use container services
● EJBContainer API (in Java EE 6)
● Arquillian
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44. Unit test with Mockito
@RunWith(MockitoJUnitRunner.class)
public class ItemEJBTest {
@Mock
private EntityManager mockedEntityManager;
@Mock
private TypedQuery mockedQuery;
private ItemEJB itemEJB;
@Before
public void init() throws Exception {
itemEJB = new ItemEJB();
itemEJB.setEntityManager(mockedEntityManager);
}
}
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45. Integration test with EJBContainer
public class ItemEJBIT {
private static EJBContainer ec;
private static Context ctx;
@BeforeClass
public static void init() throws Exception {
Map<String, Object> properties = new HashMap<>();
properties.put(EJBContainer.MODULES, new
File("target/classes"));
ec = EJBContainer.createEJBContainer(properties);
ctx = ec.getContext();
}
}
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46. Integration test with Arquillian
@RunWith(Arquillian.class)
public class ItemEJBIT {
@Inject
private ItemEJB itemEJB;
@Deployment
public static JavaArchive createTestArchive() {
JavaArchive archive = ShrinkWrap
.create(JavaArchive.class)
.addPackage(Book.class.getPackage())
.addAsManifestResource(INSTANCE, "beans.xml")
.addAsResource("META-INF/persistence.xml"..);
return archive;
}
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47. Integration Testing
●
In memory database
●
In memory container
● EJBContainer API
●
Embedded container with Arquillian
● Remote container with Arquillian
●
IT richer but slower that UT
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48. Demo of an integration test with
Arquillian

49. Portable ?
●
Java EE is a standard
●
Yaps Petstore only uses standards
●
Standards should run everywhere
●
I want my Yaps Petstore to run everywhere
● But it's not that easy
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50. JPA
●
Lazy Loading bidirectional entities
● Spec has undefined behaviour
● Works well with EclipseLink
● Doesn't with Hibernate (use Fetch Join)
● Fetch Joins don't work with EclipseLink
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51. Lazy loading
List<Product> products = em.createQuery
("SELECT p FROM Product p WHERE p.category.name =:n")
.getResultList();
for (Product product : products) {
Category category = product.getCategory();
}
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52. Lazy loading
List<Product> products = em.createQuery
("SELECT p FROM Product p WHERE p.category.name =:n")
.getResultList();
for (Product product : products) {
Category category = product.getCategory();
if (category != null)
category.getName(); Can return a proxy
}
Makes sure you get the entity
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53. Datasource
●
Needs to be defined
● In the container through admin
● Via web.xml, application.xml, ejb-jar.xml
● Or via annotation
●
Points to a database
●
In memory DB are good for development
● Each app server uses it's own in memory DB
● Derby
● Not in JBoss (add derby.jar to .war)
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54. Datasource
@DataSourceDefinition(
className ="org.apache.derby.jdbc.EmbeddedDataSource
name = "java:global/jdbc/applicationPetstoreDS",
...)
<persistence>
<persistence-unit name="applicationPetstorePU"...>
<jta-data-source>
java:global/jdbc/applicationPetstoreDS
...
</persistence>
@PersistenceContext(unitName = "applicationPetstorePU"
private EntityManager em;
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55. Default Datasource in Java EE 7
@DataSourceDefinition(
className ="org.apache.derby.jdbc.EmbeddedDataSource
name = "java:global/jdbc/applicationPetstoreDS",
...)
<persistence>
<persistence-unit name="applicationPetstorePU"...>
<jta-data-source>
java:global/jdbc/applicationPetstoreDS
...
</persistence>
@Inject
private EntityManager em;
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56. Other resources in Java EE 7
@JMSConnectionFactoryDefinition(
name="java:app/MyJMSFactory",
resourceType="javax.jms.QueueConnectionFactory",
clientId="foo",resourceAdapter="jmsra",
InitialPoolSize=5, maxPoolSize=15
)
@JMSDestinationDefinition(
name="java:app/orderQueue",
resourceType="javax.jms.Queue",
resourceAdapter="jmsra",
destinationName="orderQueue"
)
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57. Properties not all standard
<persistence-unit name="applicationPetstorePU"...>
...
<properties>
<!-- Standard Properties -->
<property name="javax.persistence.xxx" value="xxx"/>
<!-- Properties for EclipseLink -->
<property name="eclipselink.ddl-generation" value="create-tables
<!-- Properties for Hibernate -->
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
<!-- Properties for OpenJPA -->
<property name="openjpa.jdbc.SynchronizeMappings"
value="buildSchema(ForeignKeys=true)"/>
</properties>
</persistence-unit>
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58. Persistence properties in Java EE 7
<persistence-unit name="applicationPetstorePU"...>
...
<properties>
<!-- Standard Properties -->
<property name="javax.persistence.xxx" value="xxx"/>
<property name="javax.persistence.ddl" value="drop-and-create"/>
<!-- Properties for EclipseLink -->
<property name="eclipselink.ddl-generation" value="create-tables
<!-- Properties for Hibernate -->
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
<!-- Properties for OpenJPA -->
<property name="openjpa.jdbc.SynchronizeMappings"
value="buildSchema(ForeignKeys=true)"/>
</properties>
</persistence-unit>
Not sure of the syntax Not sure of the syntax
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59. Initialize database
●
Having some data in the DB
●
Running sql script
●
derbytools.jar has an API
●
Hibernate : import.sql (but not with other ORMs)
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60. Use a Singleton with @Startup
@Singleton
@Startup
public class DBPopulator {
@Inject
private CatalogService catalogService;
@PostConstruct
private void populateDB() {
catalogService.createCategory(new Category("Fish"))
}
}
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61. Demo of the Yaps Petstore
with JBoss 7.x

62. Portable ?
●
TCK doesn't cover all the cases
● e.x. all the possible JPQL query syntax
● Implementations fill (or not) black holes
●
100% portability is still a myth...
● … but it's getting better
●
… and Java EE 7 will improve some bits
●
Any way, you don't change app server every day
●
… except for the Yaps Petstore ;o)
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63. Are application servers still
fascinating for developers ?

64. Are application servers still
fascinating for developers ?
Maybe not “fascinating” but much
easier to use than before

65. Thanks
www.antoniogoncalves.org
antonio.goncalves@gmail.com
@agoncal
@lescastcodeurs

66. Thanks
●
Antoine Sabot Durand @antoine_sd
●
Jean-Louis Monteiro @JLouisMonteiro
●
Romain Manni-Bucau @rmannibucau
●
Sébastien Stormacq @sebsto
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67. Q&A

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●
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