Slides from a Java Lunch 'N Learn, where I tried to explain Java technologies to non-technical audience.

1. Business Value…Achieved
Java Lunch ‘N Learn
For QSI Talent Managers
Steinn
‘Stan’
Jónsson,
March
24,
2014
(Java
technologies
explained
to
non-­‐technical
audience)

2. Business Value…Achieved
Agenda
• How
to
sell
QSI
to
developers?
• Java
buzzwords
explained
in
layman
terms
• Q
&
A

3. Business Value…Achieved
How to sell QSI to Developers?
• See
blog
post
at:
hMp://www.sjonsson.com/2013/08/7-­‐
reasons-­‐to-­‐become-­‐soTware.html

4. Business Value…Achieved
Web
Purchase
-­‐
Example
used
to
explain
Java
buzzwords

5. Business Value…Achieved
EJB – Enterprise Java Beans
• Leave
low-­‐level
details
to
others

6. Business Value…Achieved
EJB
Get
for
free:
• Remotely
callable
• Security
• Transac]on
Management
• Scalability

7. Business Value…Achieved
• What
are
the
benefits
of
EJBs?
(Enterprise
Java
Beans)
– Sample
answers:
• Allows
me
to
focus
on
business
logic
and
solving
business
problems
• By
using
EJBs
I
need
to
worry
less
about:
– Remote
Access
– Security
– Scalability
– Transac]on
Management
EJB – Possible Interview Question

8. Business Value…Achieved
JMS – Java Message Service
• Don’t
call.
Send
a
message.

9. Business Value…Achieved
JMS

10. Business Value…Achieved
• What
are
some
benefit
of
JMS?
(Java
Message
Service)
– Sample
answers:
• Improved
performance
by
making
calls
asynchronous
(via
JMS
Queues)
• Allows
me
to
broadcast
messages
to
mul]ple
subscribers.
(Done
via
JMS
Topics.
Works
similar
to
email
mailing
lists)
JMS – Possible Interview Question

11. Business Value…Achieved
Hibernate
• Take
the
easy
route
to
your
database
• Maps
“Java
speak”
to
“database
speak”
SQL Maze

12. Business Value…Achieved
• Why
to
people
use
Hibernate?
– Sample
answers:
• To
simplify
database
persistence
• For
produc]vity
reasons
-­‐
To
avoid
having
to
manually
write
SQL
queries
• For
performance
reasons
-­‐
To
take
advantage
of
caching
• To
avoid
vendor
lock-­‐in
-­‐
Hibernate
is
database
independent
Hibernate – Possible Interview Question

13. Business Value…Achieved
The Spring Framework
• Giant
toolbox
for
simplifying
Java
development

14. Business Value…Achieved
Spring – Most used for
• Wire
the
applica]on
together

15. Business Value…Achieved
Spring – Wire the application together
BeMer
known
as
Dependency
Injec]on

16. Business Value…Achieved
• Why
do
people
use
the
Spring
Framework?
– Sample
answers:
• For
produc]vity
reasons
–
To
take
advantage
of
extensive
Spring
libraries
• Helps
“wiring
applica]ons
together”
(make
more
loosely
coupled
applica]ons
via
dependency
injec]on)
• For
performance
reasons
(Spring
container
is
more
lightweight
than
JEE
container)
Spring – Possible Interview Question

17. Business Value…Achieved
JUnit
• Automate!
Don’t
have
a
human
do
a
robot’s
job!
Unit
tests
automated.
Humans
can
focus
on
integra]on
tes]ng.

18. Business Value…Achieved
• Why
do
people
use
JUnit?
– Sample
answers:
• It
is
the
de
facto
library
for
wri]ng
tests
in
Java
• To
write
unit
tests
(and
mul]ple
other
types
of
tests)
• To
automate
tes]ng
of
their
code
JUnit– Possible Interview Question

19. Business Value…Achieved
Design Patterns
• Singleton

20. Business Value…Achieved
• What
is
a
Singleton?
– Sample
answer:
• Design
paMern
that
restricts
the
instan]a]on
of
a
class
to
one
object.
• How
to
implement
Singleton?
– Sample
answers:
• Make
constructor
private.
Class
keeps
sta]c
reference
to
instance.
Typically
has
getInstance
method.
• Use
Spring
(Spring
beans
are
Singletons
by
default)
• Use
enum
(a
single-­‐element
enum
type)
Design Patterns – Possible Interview Questions

21. Business Value…Achieved
Q & A