1. HTTP/2
Comes
to
Java
David
Delabassee
(@delabassee)
Oracle
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2. Safe
Harbor
Statement
The
following
is
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to
outline
our
general
product
direction.
It
is
intended
for
information
purposes
only,
and
may
not
be
incorporated
into
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contract.
It
is
not
a
commitment
to
deliver
any
material,
code,
or
functionality,
and
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be
relied
upon
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making
purchasing
decisions.
The
development,
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and
timing
of
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features
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described
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3. Copyright
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reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
3

4. Copyright
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2015,
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its
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rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
4

5. Copyright
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Java
EE
8
-­‐
HTML5
Support
/
Web
Tier
Enhancements
• JSON
Binding
• JSON
Processing
enhancements
• Server-­‐sent
events
• Action-­‐based
MVC
• HTTP/2
support
5

6. Copyright
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2015,
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rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
6

7. Copyright
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HTTP
1.x
1991
1996
1999
2009
2015
HTTP/0.9
HTTP/1.0
HTTP/1.1
SPDY
HTTP/2.0

8. Copyright
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Back
then…
8

9. Copyright
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Today
index.html
style1.css
style2.css
.
.
.
script1.js
script9.js
pic1.jpg
pic8.jpg
.
.
.
photo1.png
photo2.png
.
.
.

10. Copyright
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• “Conversion
Rate”
Vs.
Latency
- If
a
page
takes
longer
than
4
sec
to
load,
1/4
people
abandons
that
page
- Page
load
slowdown
of
1
sec
could
cost
Amazon
$1.6
billion
in
sales
each
year
- Slowing
search
results
by
just
0.4
sec,
Google
could
lose
8
million
searches
per
day
(http://www.fastcompany.com/1825005/how-­‐one-­‐second-­‐could-­‐cost-­‐amazon-­‐16-­‐billion-­‐sales)
10
Time
is
Money!

11. Copyright
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google.fr
(1st)
• 3
HTTP
Requests
• 21.355
bytes
- 1
HTML
- 1
image
- 1
.js
11
Top
.FR
examples
lefigaro.fr
(15th)
• 140
HTTP
Requests
• 2.736.562
bytes
- 1
HTML
- 130
images
- 6
.js
- 2
.css

12. Copyright
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HTTP
1.1
Head-­‐of-­‐Line
blocking
12
Client Server
index.html
index.html
style1.css
style2.css
script1.js
...
style1.css
style2.css
script1.js
...

13. Copyright
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HTTP
1.1

14. Copyright
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File
Concatenation
and
Image
Sprites
14
• Modern
web
page
consists
of
+90
resources
fetched
from
15
distinct
hosts
(http://httparchive.org)
• TCP
Efficiency
Improves
with
Larger
Files
• Shoving
more
than
one
logical
file
into
one
physical
file

15. Copyright
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File
Concatenation
and
Image
Sprites
15

16. Copyright
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HTTP
1.1
Workaround
-­‐
Domain
Sharding
16

17. Copyright
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Asset
inlining
…
<img
src="data:image/gif;base64,R0lGODlhEAAOexs3eeALMAAOazToeHh0tLS/
7LZv0jvb29tf3Ubge8WSLrhf3kdbW1mxsjkhfkjfhGHhcjGDSHJUYgJvhgtyrHgfGfHy
t56HGfGH56ge8WSLf6GGHhfkjfhhfkjfhpBREzxvt6QAA4lsjkhfkjfhdxwqBnuIoYty
GhBKoOjJj6GGHvvhdsbxus38GV3pBREzxvt6QAA4lsjkhfkjfhdxwqBnuIoYtyGhBKoO
jJj6GGHvvhdsbxus38GV3vvhdsbxusbasbPmfyH5BAAAjAAAALAAfhGHhcjAAAAQAA4l
sjkhfkjfhGHhcjGDSHJUYgJvhgtyrHgfhfkjfhpBREzxvt6QAA4lsjkhfkjfhdxwqBnu
IoYtyGhBKoOjJj6GGHvvhdsbxus38GV3GfHyt56HGfGH56ge8WsjkhfkjfhGHhcjGDSH
JUYgJvhgtyrHgfGfHyt56HGfGH56gebxus38G8WSLf6GGHvvhdsbxusbaSLf6GGHvvhd
sbxusbaOiQA4lsjkhfkjf4lsjkhfkjf4lsjbxus38GkhfkjfhfkjfhpBREzxvt6QAA4l
sjkhfkjfhdxwqBnuIoYtyGhBKoOjJj6GGHvvhdsbxus38GV3DcPjjBceXsplojj…”
/>
…

18. Copyright
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• HTTP
uses
TCP
poorly
- HTTP:
short
and
bursty
flows
Vs.
TCP:
optimized
for
long-­‐lived
flows
• Solutions
- Sprites
- Domain
sharding
- Assets
Inlining
- File
concatenations
- …
18
HTTP/1.1
circa
1999
Problems
Vs
Solutions
1991
1996
1999
2009
2015
HTTP/0.9
HTTP/1.0
HTTP/1.1
SPDY
HTTP/2.0

19. Copyright
©
2015,
Oracle
and/or
its
affiliates.
All
rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
19

20. Copyright
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HTTP/2
Features
• Binary
Framing
over
single
TCP
connection
• Request/Response
multiplexing
• Stream
Prioritization
• Server
Push
• Upgrade
from
HTTP
1.1
• Header
Compression

21. Copyright
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HTTP/2
• Fully
bi-­‐directional
– Connection
A
TCP
socket
– Message
A
logical
HTTP
message,
such
as
a
request
or
a
response
– Stream
A
bi-­‐directional
“channel”
within
a
connection,
carry
one
or
more
message
– Frame
The
smallest
unit
of
communication
in
HTTP/2
21
Lets
you
do
more
things
with
a
single
TCP
connection

22. Copyright
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HTTP/2
22
Connections,
Streams,
Messages,
Frames

23. Copyright
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Binary
Frames
• Frames
- HEADERS,
DATA,
PRIORITY,
RST_STREAM,
SETTINGS,
PUSH_PROMISE,
PING,
GOAWAY,
WINDOW_UPDATE,
CONTINUATION
- Prioritisation,
Flow
Control,
Server
Push,
…
• Single
TCP
Connection
23
POST
/upload
HTTP/1.1
Host:
www.test.com
Content-­‐Type:
application/json
Content-­‐Length:
15
{“name”:“duke”}
HTTP
1.1 HTTP/2
HEADERS
frame
DATA
frame

24. Copyright
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Multiplexing
24

25. Copyright
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Stream
Prioritization
• Stream
Dependency
in
HEADERS
Frame
• PRIORITY
frame
type
• An
additional
40
bytes
- Stream
id
(31)
- Weight
(8):
[1,
256]
- Exclusive
bit
(1)
• Only
an
advice
25
A
B C
4 12
A
B CD
4 16 12
exclusive
=
0
A
B C
D
4 12
16
exclusive
=
1

26. Copyright
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rights
reserved.
Server
Push
/index.html
stream
1
/style.css
stream
2
/script.js
stream
4
Client Server
stream
1
HEADERS
stream
1
DATA
stream
2
PROMISE
stream
4
PROMISE
26
• No
corresponding
JavaScript
API
• Can
be
combined
with
SSE

27. Copyright
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rights
reserved. 27
Header
Compression
27
HPack

28. Copyright
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rights
reserved. 28
Upgrade
from
HTTP
1.1
• HTTP
- Port
80
- HTTP
Upgrade
to
“h2c”
(101
Switching
Protocol)
• HTTPS
(*)
- Application
Layer
Protocol
Negotiation
(ALPN)
- Next
Protocol
Negotiation
(NPN)
(*)
TLS
is
not
mandatory
28

29. Copyright
©
2015,
Oracle
and/or
its
affiliates.
All
rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
29

30. Copyright
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rights
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• Request/Response
multiplexing
• Binary
Framing
• Stream
Prioritization
• Server
Push
• Header
Compression
• Upgrade
from
HTTP
1.1
– ALPN
or
(NPN)
– 101
Switching
Protocols
30
HTTP/2

31. Copyright
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• Request/Response
Multiplexing
• Binary
Framing
• Stream
Prioritization
• Server
Push
• Header
Compression
• Upgrade
from
HTTP
1.1
– ALPN
or
(NPN)
– 101
Switching
Protocols
31
Features
Potentially
Exposed
in
Servlet
API
HTTP/2

32. Copyright
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• New
HttpServletRequest
and
HttpServletResponse
method
– int
getStreamId()
32
Stream
Prioritization

33. Copyright
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• New
class
Priority
– boolean
exclusive
– int
streamId
– int
weight
• New
method
to
HttpServletRequest
– Priority
getPriority()
• New
methods
to
HttpServletResponse
– Priority
getPriority()
– void
setPriority(Priority
p)
33
Stream
Prioritization

34. Copyright
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• Push
resource
to
client
for
a
given
url
and
headers
• May
add
callback
for
completion
or
error
of
a
push
• Not
a
replacement
for
WebSocket
34
Servlet
4.0
Server
Push

35. Copyright
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Server
Push
public
class
ExternalContextImpl
extends
ExternalContext
{
//…
public
String
encodeResourceURL(String
url)
{
if
(null
==
url)
{
String
message
=
MessageUtils.getExceptionMessageString
(MessageUtils.NULL_PARAMETERS_ERROR_MESSAGE_ID,
"url");
throw
new
NullPointerException(message);
}
Map
attrs
=
getResourceAttrs();
((HttpServletRequest)
request).dispatchPushRequest(url,
attrs);
return
((HttpServletResponse)
response).encodeURL(url);
}
//…
}
Example
of
Potential
Use
from
JSF
35

36. Copyright
©
2015,
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and/or
its
affiliates.
All
rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
36

37. Copyright
©
2015,
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affiliates.
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rights
reserved.
Java
SE
9
Support
for
HTTP/2
• JEP
110
- http://openjdk.java.net/jeps/110
• Easy
to
use
API
• Covers
only
the
most
common
use
cases
• Supports
both
HTTP
1.1
and
2
37

38. Copyright
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rights
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Java
SE
9
Support
for
HTTP/2
• 2
classes
– HttpRequest
:
one
request/response
interaction
– HttpRequestGroup
:
configuration
for
multiple
requests
• Blocking
mode:
one
thread
per
request/response
– send
request
&
get
response
• Non-­‐blocking
mode:
handle
multiple
request/response
interactions
in
single
thread
using
non-­‐blocking
API
– analogous
to
NIO
selectors
Small
footprint
38

39. Copyright
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rights
reserved.
Java
SE
9
Support
for
HTTP/2
HttpRequestGroup
group
=
HttpRequestGroup.create();
HttpRequest
req
=
group.createRequest()
.setRequestMethod("POST")
.setRequestURI(new
URI("http://www.foo.com/a/b")
.setRequestBody("Param1=1,Param2=2")
.onResponseHeader("X-­‐Foo",
(request,
name,
value)
-­‐>
{
System.out.printf("
received
an
X-­‐Foo
header");
})
.sendRequest()
.waitForCompletion();
39

40. Copyright
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2015,
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its
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rights
reserved.
Java
SE
9
Support
for
HTTP/2
HttpRequestGroup
group
=
HttpRequestGroup.create();
HttpRequest
req
=
group.createRequest()
…
.onResponseBody((HttpRequest
request,
InputStream
in)
-­‐>
{
if
(request.getResponseCode()
==
200)
{
Path
out
=
Paths.get("/tmp/out");
try
{
Files.copy(in,
out);
}
finally
{
in.close();
}
}
})
.sendRequest()
.waitForCompletion();
40

41. Copyright
©
2015,
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and/or
its
affiliates.
All
rights
reserved.
Agenda
Java
EE
8
Why
HTTP/2?
HTTP/2
Big
Features
HTTP/2
and
Java
EE
HTTP/2
and
Java
SE
Summary
41

42. Copyright
©
2015,
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and/or
its
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rights
reserved.
HTTP/2
• Address
the
Limitations
of
HTTP
1.x
- Improve
performance
- Reduce
latency
- Improve
ressources
utilization,
etc.
• “Compatible
with
HTTP/1.1”
- Retain
semantics
of
HTTP
1.x
- Define
interaction
with
HTTP
1.1
• “TLS
not
mandatory”
42
Hypertext
Transfer
Protocol
version
2
&
HPACK

43. Copyright
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2015,
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and/or
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rights
reserved.
“HTTP/2
is
nearly
done
standardization”
• Jan
2015
Enabled
by
default
in
FireFox
(35)
and
Chrome
(40)
• Feb
2015
IESG
approved
HTTP/2
• May
2015
HTTP/2
in
10%
of
all
HTTP
responses
(FireFox)
(*)
HTTP/2
used
in
18%
of
global
traffic
(Google)
(*)
HTTP/2
is
supported
by
44%
of
browsers
in
user
right
now
(*)
In
RFC
Editor’s
publication
queue
(*)
http://daniel.haxx.se/blog/2015/05/07/http2-­‐for-­‐tcpip-­‐geeks/
43

44. Copyright
©
2015,
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and/or
its
affiliates.
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rights
reserved.
HTTP/2
and
Java
• Servlet
4.0
brings
HTTP/2
to
Java
EE
- 100%
compliant
implementation
of
HTTP/2
- Expose
key
features
to
the
API
• Server
Push
• Stream
Prioritization
• HTTP
1.1
upgrade
• JDK
9
brings
HTTP/2
support
to
Java
SE
• TBC!
44
Plans

45. Copyright
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2015,
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and/or
its
affiliates.
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rights
reserved.
Resources
• https://java.net/projects/servlet-­‐spec/
• http://glassfish.org/adoptajsr
• http://openjdk.java.net/jeps/110
• http://http2.github.io
• http://chimera.labs.oreilly.com/books/1230000000545/ch12.html
45

46. Copyright
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2015,
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its
affiliates.
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rights
reserved. 46