Presentation on Java EE 6 CDI with a twist of bashing Spring. Held at Callista Developers Conference 2010.

1. The
New
Java
EE
CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6.
BeAer
than
Spring?
Johan
Eltes
|
johan.eltes@callistaenterprise.se
|
Cadec
2010-­‐01-­‐20
onsdag 27 januari 2010 1

2. Once
upon
a
time
Spring
was
comprehensible…
1 0
20
0 8
20
0 4
20
2 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 2

3. Are
you
a
Java
or
XML
developer?
3 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 3

4. Spring
wasn’t
built
bottom
up
for
noxml
Spring
wasn’t
built
bo?om
up
for
noXML
You
need
to
understand
what
can
be
done
using
JavaConfig
/
annotaFons
and
when
to
step
down
to
XML.
There
are
so
many
options
in
Spring
that
you
need
a
100
page
company-­best-­practice
guide
so
that
developers
can
read
each
others
code.
4 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 4

5. Complex
tools
require
tool
suites
5 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 5

6. Meanwhile,
Java
EE
is
shrinking...
o Rile
Pr
eb
6
W
a
EE
Jav
E
va
E
l l
Ja
Fu
6 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 6

7. ...and
moving
to
a
very
slick
DI-­based
component
model:
CDI
CDI
requires
support
from
an
EJB
3.1
Light-­‐
container
for
EJB-­‐
CDI
container
(injecKon,
aop,
contexts) specific
capabiliKes
(transatcions,
security)
JSF/Facelets
Managed
Bean
Special
case:
EJB
Session
and
Singleton CDI
container
CDI
container
will
offer
the
will
resolve
bean
for
dependency injecKon
Servlets
MDBs WS
CDI
consolidates
JSR
250
(common
annota7ons),
JSR-­‐330
( javax.inject)
and
“EJB
3.1
light”
into
a
unified
“POJO”
component
model.
7 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 7

8. So,
let’s
have
a
look
at
CDI!
All demo code for the use-cases are available for public checkout at this
svn repo:
• Use-­‐cases
for
CDI https://svn.callistaenterprise.se/public/Cadec/Cadec2010/cdi/trunk
– UC
1:
Basic
DI
for
Unit
tesKng
– UC
2:
Factories
and
qualifiers
– UC
3:
IntegraKon
tesKng
in
JUnit
– UC
4:
AOP
with
interceptors
– UC
5:
Loose
coupling
with
events
– UC
6:
Handling
of
scopes
– UC
7:
Extensions
AnnotaKons,
annotaKons,
annotaKons...
@Inject,
@Produces,
@Qualifer,
@AlternaKve,
@Stateless,
@ConversaKon
8 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 8

9. UC
1:
Basic
DI
for
Unit
testing
Interface:
OrderDao Class
OracleOrderDaoImpl extends
Class
OrderServiceImpl
{ OrderDao
@Inject
OrderDao
orderDao;
... ?
}
Class
MySqlOrderDaoImpl extends
OrderDao
Class
MockOrderDaoImpl extends
OrderDao
@Inject
is
by
default
auto-­‐injecKon
by
type
9 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 9

10. 9
UC
2:
Factories
and
qualiRiers
Instance of
Class JmsTemplate: @DestClass(ERROR)
Interface:
receiveTimeout: 3000
defaultDestinationName: “error.queue”
JmsTemplate ...
Instance of
Class JmsTemplate: @
DestClass(LOG)
Class
OrderServiceImpl
{ receiveTimeout: 100
@Inject defaultDestinationName: “log.queue”
JmsTemplate
@JTQualifer(ERROR) ...
errorDestTemplate; ?
... Instance of
} Class JmsTemplate: @Named(“service1”)
receiveTimeout: 4000
defaultDestinationName: “service1”
...
Class
JmsTemplateFactory
{
@Producer
@DestClass(ERROR)
JmsTemplate
getErrorDestTemplate()
{}
@Producer
@DestClass(LOG)
JmsTemplate
getLogDestTemplate()
{}
@Producer
@Named(“invoice”)
JmsTemplate
getInvoiceDestTemplate()
{}
}
With
@Produces
we
can
create
mulKple
beans
of
the
same
type
With
@Qualifier-­‐annotaKons,
we
select
which
bean
to
inject
10 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 10

11. UC
3:
Integration
testing
with
JUnit
How
much
weight
has
EJB
lost??
Demo:
JUnit
TestCase-­‐>TestEjb-­‐>Ejb-­‐>Dao-­‐>JPA
...with
embeddable
EJB
container
11 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 11

12. 9
UC
4:
Cross-­cutting
concerns
Class
OrderServiceImpl
{
Interface:
OrderDao
@Inject @Trace
OrderDao
orderDao; Class OracleOrderDaoImpl extends OrderDao
... {
} Order save(Order order) {
}
}
@Trace @Interceptor
public class TraceLogInterceptor {
@AroundInvoke
public Object trace(InvocationContext
ctx)
throws Exception { ... }
}
Sample:
Trace
entry
and
exit
of
method
invocaKons
in
all
classes
annotated
with
@Trace
12 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 12

13. UC
5:
Events
Class CustomerFormBean {
@Inject Class CustomerServiceImpl {
CustomerService cs; @Inject @Deleted
Event<Customer>
public void delete(Customer deletedEvent;
c) {
cs.delete(c) public void delete(Customer c)
} {
} ... “CDI Event broker”
deletedEvent.fire(c);
}
Class
OrderServiceImpl
{
}
@Inject
OrderDao
od;
public
void
validateDelete(@Observes
@Deleted
Customer
c)
{
if
(od.hasOrderForCustomer(c))
throw
new
VetoExcepKon();
}
}
Order
service
listens
to
customer
deleKon
events
to
prevent
deleKon
of
customers
with
orders.
13 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 13

14. UC
6:
Declarative
scope
management
• ejb
Session CDI handles the scoping /
context aspects of EJBs as
• ejb
Singleton well (without an EJB
container)
• ApplicaKonScoped
• RequestScoped
• SessionScoped
• ConversaKonScoped
• AddiKonal
scopes
may
be
added
via
extenKon
api
(“SPI”)
Use-­‐case
5:
Contextual
services
14 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 14

15. 9
UC
7:
Extentions
-­
Sample:
conRig
Rile
Instance of
Class JmsTemplate: @DestClass(ERROR)
Interface:
receiveTimeout: 3000
defaultDestinationName: “error.queue”
JmsTemplate ...
Instance of
Class JmsTemplate: @
DestClass(LOG)
Class
OrderServiceImpl
{ receiveTimeout: 100
@Inject defaultDestinationName: “log.queue”
JmsTemplate
@JTQualifer(ERROR) ...
errorDestTemplate; ?
... Instance of
} Class JmsTemplate: @Named(“invoice”)
receiveTimeout: 4000
defaultDestinationName: “invoice.queue”
...
Class
JmsTemplateFactory
{
@Producer
@DestClass(ERROR)
JmsTemplate
getErrorDestTemplate()
{}
@Producer
@DestClass(LOG)
JmsTemplate
getLogDestTemplate()
{}
@Producer
@Named(“invoice”)
JmsTemplate
getInvoiceDestTemplate()
{}
}
Sample:
Extension
for
file-­‐based
configuraKon
of
@Producers
15 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 15

16. Is
Java
EE
6
and
CDI
for
me?
• Why?
– Java
EE
development
is
FUN
(producKve)
again!
– It
is
a
neat,
simple
model
– Zero
config
/
overhead
/
layers
if
you
want
to
start
simple
– Do
we
sKll
need
“help”
from
Spring?
• When?
– JBoss,
Oracle
and
Sun
seems
to
be
there
“soon”
– Likely
to
get
OS-­‐extensions
that
bring
it
to
Tomcat
very
soon
• Who?
– Very
good
news
for
no-­‐floss-­‐shops
:)
– OpKon
for
building
up
Spring
competence
-­‐
Java
EE
6
Web
Profile
is
likely
an
easier
start
16 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 16

17. Thank’s
for
listening!
17 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 17

18. Credits
• Image
of
feathers:
– hAp://askabiologist.asu.edu
18 CDI
-­‐
the
re-­‐invented
component
model
for
Java
EE
6 ©
2010
Callista
Enterprise
|
www.callistaenterprise.se
onsdag 27 januari 2010 18