Presented on JavaOne 2015. Take JAX-RS, WebSocket, and the idea of microservices; put the ingredients into a pressure cooker; raise the temperature; and let the experiments begin. In this session, you’ll witness a core foundation being cooked for building (micro-)applications using REST (JAX-RS) and WebSocket together, a foundation that is memory-efficient, fast, and easy to work with. And as a cherry on top, new features (lambdas) and types (streams, optionals, dates, and more) of Java 8 will be added into the mix of these Java EE technologies. Last but not least, the presenters want to hear about your encounters with running WebSocket and JAX-RS together. Do you run microservices-like deployments and have some unresolved issues or ideas about how that experience can be improved? Github repo: https://github.com/pavelbucek/placeholder

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3
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Training
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Learning
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• Oracle
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Survey
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5. How to Thrive on REST/
WebSocket-based Microservices
Pavel
Bucek
(pavel.bucek@oracle.com)
Michal
Gajdoš
(michal@sapho.com)
Oracle/Sapho
October
27,
2015
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Safe
Harbor
Statement
The
following
is
intended
to
outline
our
general
product
direcFon.
It
is
intended
for
informaFon
purposes
only,
and
may
not
be
incorporated
into
any
contract.
It
is
not
a
commitment
to
deliver
any
material,
code,
or
funcFonality,
and
should
not
be
relied
upon
in
making
purchasing
decisions.
The
development,
release,
and
Fming
of
any
features
or
funcFonality
described
for
Oracle’s
products
remains
at
the
sole
discreFon
of
Oracle.
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IntroducFon
7

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Why
are
we
doing
this?
• Proof
of
concept
– Micro
is
the
new
black
– Very
small
runFme
can
deliver
key
funcFonality
• JAX-­‐RS
(Jersey)
+
WebSocket
(Tyrus)
• Java
SE
8
adopFon
• ReacFve
APIs
8

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What’s
already
there?
• Vert.x
• Dropwizard
– JeQy,
Jersey,
Jackson,
…
– No
WebSocket
• Glassfish
/
Payara
– JAX-­‐RS,
WebSocket,
Servlet,
JSF,
BV,
CDI,
…
– ~60MB
9

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QUESTION
Typical
produc7on
deployment
in
my
company
is:
Micro-­‐service
(small
containers,
dynamic
up/down
scaling)
Monolithic
applicaFon
(big
containers,
staFc
resources,
acFve/
passive
backup)
CombinaFon
of
previous
A
B
C
10

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Sample
applicaFon
• Simple
poll
– Jersey
MVC
• Results
are
updated
based
on
new
votes
– WebSocket
connecFon
(could
be
SSE..)
• Simple
filtering
(websocket
based)
– InteracFve
part
of
the
app
– WebSocket
are
more
efficient
to
use
11

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DEMO
How
does
the
Survey
app
works?
12

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QUESTION
Which
Java
framework
do
you
use
in
produc7on?
Java
EE
6+
Spring
Java
EE
5
(and
older)
+
Java
SE
Something
else,
text
us
what!
A
B
C
13
D

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DEMO
+CDI
14

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QUESTION
Do
you
use
WebSocket
in
produc7on?
Yes.
Not
yet,
but
we
plan
to.
No
(we
don’t
need
bi-­‐direcFonal
communicaFon).
No
(we
use
something
else).
A
B
C
15
D

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Micro-­‐services
• Simple,
small,
decoupled
standalone
“applicaFons”
– They
don’t
do
(and
provide)
anything
else
than
they
should
– Easy
to
develop
and
test
• Fast
startup
Fme,
Fault
tolerant
– Dynamic
scaling
– CaQle
vs
Pet
16

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<<Placeholder>>
17

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<<Placeholder>>
• Grizzly
– HTTP
container
• HK2
– Dependency
InjecFon
• Tyrus
– WebSocket
RI
• Jersey
– JAX-­‐RS
RI
18

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DEMO
<<Placeholder>>
19

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QUESTION
Executable
JAR
size
(<<Placeholder>>
+
poll
app)
is:
~100
MB
~50
MB
~20
MB
~10
MB
~5
MB
A
B
C
20
D
E

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Summary
• Glassfish
– Footprint:
>200
M
– Startup
Fme:
~10
s
• JeQy
+
Weld
– Footprint:
~28
M
– Startup
Fme:
~5
s
• <<Placeholder>>
– Footprint:
~11
M
– Startup
Fme:
~1s
21

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What
do
we
miss?
22

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Java
8
+
ReacFve
APIs
• Lots
of
new
features
in
Java
8
• Frameworks
slowly
up-­‐taking
new
APIs
• OpFonal,
Lambdas,
Streams,
…
• ReacFve
APIs
are
very
handy
when
you
are
accessing
more
services
– You
don’t
need
to
wait
(block)
for
the
answer
– Processing
hooked
to
“response(s)
received”
23

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QUESTION
Java
version
in
produc7on:
Java
5
(and
older)
Java
6
Java
7
Java
8
Java
9
(for
cuwng-­‐edge
enthusiasts)
A
B
C
24
D
E

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OpFonal
in
Jersey
• Server
– Incoming
enFFes
– Return
values
(Outgoing
enFFes)
– @*Param
values
• Client
– Outgoing
enFFes
25

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OpFonal
in
Jersey
26

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OpFonal
in
Jersey
27

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ReacFve
Client
API
in
Jersey/JAX-­‐RS
2.1
• UFlize
the
reacFve
programming
model
when
using
Jersey/JAX-­‐RS
Client
• Already
in
Jersey
– Java
8
–
CompleFonStage
– RxJava
– Guava
• Will
be
in
JAX-­‐RS
2.1
28

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ReacFve
Client
API
–
Jersey
&
RxJava
29

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ReacFve
Client
API
–
JAX-­‐RS
2.1
&
CompleFonStage
30

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ProgrammaFc
Resources
in
Jersey
31

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Lambdas
in
Tyrus
• Endpoint
is
just
a
set
of
lambda
funcFons
– @OnOpen,
@OnMessage,
@OnError,
@OnClose
– WebSocket
API
already
has
programmaFc
version
in
the
specificaFon
–
see
javax.websocket.Endpoint
• It
can
be
applied
to
server
side
as
well
– AnnotaFon
way
is
o{en
preferred
for
server-­‐side
deployment
– Easier
to
read
+
integrate
with
other
frameworks
(DI,
..)
32

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Lambdas
in
Tyrus
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Lambdas
in
Tyrus
34

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Lambdas
in
Tyrus
35

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Streams
in
Tyrus
• Stream
processing
is
another
bigger
and
more
notable
feature
of
the
Java
8
• MessageHanders
(in
general
-­‐
any
event
handler)
can
be
modeled
as
endless
stream
– there
are
some
issues
with
“terminators”,
but
that
could
be
solved
-­‐
terminator
would
unregister
current
“message
handler”;
push
vs
pull..
– streams
can
easily:
filter,
map
(encode/decode)
36

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Contacts
• Pavel
Bucek
(pavel.bucek@oracle.com)
• Michal
Gajdoš
(michal@sapho.com)
Github
repo:
hQps://github.com/pavelbucek/placeholder
• Jersey
–
hQp://jersey.java.net
• Tyrus
–
hQp://tyrus.java.net
37

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Q
&
A
38

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