Java Magazine 2016 01-02

30.3 MB·English

by  Oracle

JAVA 9 MODULARITY 59 | GOSU LANGUAGE 65 | KUMULUZEE 80
BEHIND THE UI
WRITING
WEB APPS
JANUARY/FEBRUARY 2016
15
SPRING BOOT:
FAST, EASY WEB
APPLICATIONS
23
OMNIFACES:
COMPREHENSIVE
JSF UTILITY
31
JAX-RS 2.0:
THE LITTLE-USED
FEATURES
41
LONG-LIVED
SERVER
CONNECTIONS
ORACLE.COM/JAVAMAGAZINE
//table of contents /
23 31 41 47
15 FIRST STEPS WITH
OMNIFACES: JAX-RS 2.0: LONG PUSHING
SPRING BOOT
MAKING JSF USING ALL THE POLLING WITH DATA IN BOTH
A LOT EASIER GOODNESS ASYNCHRONOUS DIRECTIONS
By Josh Long SERVLETS WITH
By Anghel Leonard By Abhishek Gupta
The new Spring
WEBSOCKETS
Solve many day-to-day Understanding the
By Henry Naftulin
framework brings
JSF problems with client API, filters, The reliable workhorse
By Danny Coward
long-awaited ease
a single, integrated interceptors, and other of client/server Build on WebSockets’
of development
utility library. useful REST features communications is long-lasting connec-
to web apps.
the easy-to-use tions to create a simple
fallback when other chat app
methods don’t work.
COVER ART BY I-HUA CHEN
03 59 72 89
From the Editor Path to Java 9 Containers Fix This
The Rise and Fall of Languages in 2015 An Early Look at Java 9 Modules Using Multiple Docker Containers By Simon Roberts
Our latest code challenges
06 By Ben Evans By Arun Gupta
Preparing for modularity—the biggest Assemble a cluster of Docker containers
Letters to the Editor 40
change by far in the next release of Java and run a Java EE app—without a lot of
Comments, questions, suggestions, Java Proposals of Interest
housekeeping.
and kudos 65 JEP 254: Compact Strings
JVM Languages 80
08 71
Gosu: A Modern, Down-to-Earth Microservices
Events User Groups
Language for the JVM KumuluzEE: Building
Upcoming Java conferences and events Manchester Java Community
Microservices with Java EE
By Scott McKinney
11 A low-ceremony language used in 93
By Tilen Faganel and Matjaz B. Juric
Java Books enterprise apps offers an extraordinarily Develop self-contained microservices Contact Us
Reviews of two Java tutorials flexible, yet static, type system. with standard Java EE APIs using the Have a comment? Suggestion? Want to
open source KumuluzEE framework. submit an article proposal? Here’s how.
01
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//from the editor /
The Rise and Fall of Languages in 2015
An unusually good year for Java and JVM languages
F
or the last few years, in my first editorial of data extracted from GitHub, the popular host
the new year, I’ve looked at how programming for open source and private projects; Open Hub,
languages fared during the previous calendar year. which surveys all active open source projects; and
Despite the general perception that changes in Google Trends. Each measure quantifies different
language popularity are slow-moving affairs, pro- things, and it’s important to look at the data in
gramming languages often suffer sudden declines context before determining what useful informa-
(Objective-C) or enjoy unexpected surges (Java, as tion it provides.
I’ll explain in a moment). The most widely used By most measures, Java had a banner year.
measure of popularity is the TIOBE Index, which TIOBE just named Java Language of the Year for
counts searches for languages and normalizes 2015 because it enjoyed the greatest jump of any
the results to a percentage of the total number of language in terms of percentage of searches.
searches. Whether web searches are an accurate TIOBE attributes this surge to the use of Java on
proxy for popularity is a point of some conten- Android. I believe this is true, but it’s only part of
tion; however, the TIOBE Index has one significant the story. The rapid adoption of Java 8 certainly
advantage: it provides data for the index going contributed, too. Java’s surge definitively lays to
back 15 years. This makes it possible to identify rest the trend of click-bait articles inquiring “Is
multiyear trends easily. Java Dead?” in which pundits invariably concluded
Good analysis of language popularity neces- after lots of explanation that it’s not dead.
sarily relies on additional sources. I also rely on GitHub is a good way to measure popularity
PHOTOGRAPH BY BOB ADLER/GETTY IMAGES 03
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//from the editor /
among younger programmers. years in order to move out of the the most interesting trend, which
Here, too, Java is hot. It cur- margins. I’m curious to see if it appears in multiple indexes,
rently sits behind only JavaScript will cross this chasm. Several is that JavaScript’s popularity
in popularity. This represents a years ago, the biggest complaints appears to have peaked. A few
remarkable ascent. GitHub ini- about Scala were the binary years ago, its ubiquity on front
tially rose to popularity in the incompatibility of new releases, ends (both web and mobile) and
Ruby community. In 2008, Java slow compile times, and lan- the advent of Node.js suggested
was the seventh most popular guage complexity. Today, the last that it might become the new
language on GitHub; Ruby was two concerns remain important universal programming language
first. Java’s ascent of five posi- obstacles. Meanwhile, languages (see Atwood’s Law). But limita-
tions in the intervening years such as Kotlin, which is viewed tions of the language make it
is unmatched. During the same by many as a direct competitor, difficult to use on large-scale
period, no programming lan- are putting pressure on Scala. So projects. The result has been
guage has managed to rise more is Java indirectly. Scala’s claim to the growth of JavaScript trans-
than two slots. I expect its popu- fame is that it enables developers piling alternatives such as Dart,
larity to continue due to Java’s to mix object-oriented (OO) and CoffeeScript, and TypeScript. Of
ubiquity on the cloud (every functional paradigms. But Java 8 these, I personally most admire
major cloud provider supports introduced functional program- TypeScript, which also appears
it) and its central role in the ming elements, which, while to be gaining the most traction
Internet of Things. far more modest than Scala’s, among developers. I’ll be curi-
Among third-party JVM lan- might induce businesses think- ous to see whether the approval
guages, the only two entrants ing of looking to Scala for its of the ECMAScript 6 standard
to make it into the TIOBE top functional-OO hybrid qualities to (also known as ECMAScript 2015)
50 or to be ranked by Open Hub stay put. in June of last year will improve
are Groovy (#17) and Scala (#30). Developers who prefer the func- JavaScript’s popularity. We’ll
On TIOBE, Groovy had a banner tional paradigm will be pleased check in next year.
year. It’s hard to know the cause to know that TIOBE expects that Language features and projec-
of this, although progress in the Clojure, with its Lisp-like syn- tions of future language adoption
chief complaint against it— tax and currently sitting in third are among the most enjoyable
performance—has surely helped. place among JVM languages, will discussions in programming. Let
In open source projects, Scala soon advance to the honor roll me know if you have different
has the upper hand in popular- of top 50 languages. Meanwhile, views from mine.
ity. This suggests that Groovy is other functional languages, such
Andrew Binstock, Editor in Chief
more popular in business con- as Haskell and Erlang, both broke
[email protected]
texts, which is a transition that into the top 40 spots.
@platypusguy
Scala must make in the next few In non-JVM languages, perhaps 04
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AOT Compilation

Has Come to Java 8
Excelsior JET 11 supports Java SE 8 and JavaFX 8 on all desktop platforms.
Try It Now
Registration-Free, 90-Days Trial Download
//letters to the editor /
More JavaFX and Introductory
Unreasonable Effectiveness of the DRE would be 90 percent.
Articles
Static Analysis,” September/ The current US average for
Java Magazine used to run arti- October 2015 issue, page 3). You DRE is about 92 percent, but top
cles for developers new to Java were kind enough to quote some projects can get up to 99.5 per-
in every issue. In addition, there of the statistics I published ear- cent. This average value is based
were occasional articles on lier. Let me make some comments on both pretest removal and
JavaFX. Is it possible to continue and add some more information. the six normal test stages used
publishing such articles? Static analysis is among the
—Marius Claassen most effective forms of defect
TECHNIQUE DEFECT
removal, and also fairly inexpen-
REMOVAL
Editor Andrew Binstock responds: sive and fairly rapid. It can be used
SEPTEMBER/OCTOBER 2015 RATE
Thanks for your note. Readers’ sug- for both development and also for
FORMAL INSPECTIONS 87%
gestions about what to cover more removing latent bugs in legacy
frequently are very helpful to us. applications. As you pointed out, STATIC ANALYSIS 55%
We will be resuming the beginner false positives are much lower EXTERNAL BETA TEST > 1,000 52%
series in the next issue, and it should today than they were 10 years CLIENTS
become a regular feature. Michael ago. I think static analysis should
SYSTEM TEST—CERTIFIED TESTERS 46%
Kölling—the author of the previous become a standard software qual-
INFORMAL PEER REVIEWS 45%
series on introductory topics—will be ity method that is used on just
SYSTEM TEST—UNCERTIFIED 36%
the author. His focus will be on lan- about 100 percent of all software
DEVELOPERS
guage features, especially the dark applications, with one caveat—the
corners where unexpected or unusual tool is simply not available for FUNCTION TEST 35%
behaviors are found. many languages except the 30 or COMPONENT TEST 32%
You might have seen in the so most popular ones.
UNIT TEST 30%
September/October issue that we However, its effectiveness is
covered TestFX, a way of testing undeniable. Table 1 shows the EXTERNAL BETA TEST < 1,000 28%
CLIENTS
JavaFX apps. And we do have a cou- approximate defect removal effi-
DESK CHECK 27%
ple of additional JavaFX articles in ciency (DRE) values for a sample
the pipeline. If we see an increase in of pretest removal and for test PAIR PROGRAMMING 22%
demand for JavaFX articles, we will stages. The DRE metric was devel-
ACCEPTANCE TEST 17%
cover the topic even more. oped by IBM circa 1973 as a tool
REGRESSION TEST 14%
for validating the effectiveness of
How Effective Is Static
inspections. It is a simple metric. PERFORMANCE TEST 12%
Analysis?
If developers find 90 bugs and a Table 1. Defect removal efficiency (in
Thank you for your editorial on customer reports 10 bugs in the descending order) for pretest and test
techniques
the value of static analysis (“The first three months of use, then 06
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//letters to the editor /
for most software (unit test, function
test, regression test, performance test,
system test, and acceptance test). Of
course, some critical software—such as
medical devices and weapons systems—
might use more than 12 test stages and,
therefore, exceed 99 percent in DRE.
DRE is only half of the IBM quality
metric set. The other half was “defect
potential” or the sum of the bugs found
in many sources. Today, defect poten-
tial is measured using function point
metrics because “lines of code” isn’t a
useful measure for requirements and
design bugs. The current US average is
about 4.5 bugs per function point, which
represents the total of all bugs found
in requirements, architecture, design,
code, user documents, and “bad fixes”
or new bugs in bug repairs.
Once again, thank you for a good
article. I hope this additional informa-
tion will be helpful.
—Capers Jones
VP and CTO, Namcook Analytics LLC
Contact Us
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this in your message. Please write to us
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ways to reach us, see the last page of
this issue. 07
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//events /
Topconf Linz
presentations. Featured tracks
FEBRUARY 1–3 include HTML5 and JavaScript,
LINZ, AUSTRIA Java SE/Java EE/Spring, and
This conference focuses on data and integration.
new ways to manage mobile,
Apache Hadoop Innovation
Java, cloud, front end, security,
Summit
and more. Workshops include
FEBRUARY 18–19
sketching web and app inter-
SAN DIEGO, CALIFORNIA
faces, microservices and event
With presentations from more
sourcing with Spring Boot, and
than 25 hands-on industry
software management in a
speakers, topics covered will
lean and agile world.
include MapReduce and Spark,
Jfokus building privacy-protected
FEBRUARY 8–10 data systems, scalable data
STOCKHOLM, SWEDEN curation, best practices, and
Jfokus has run for eight years architectural considerations for
and is the largest annual Hadoop applications.
Java developer conference
Mobile World Congress
in Sweden. Conference topics
FEBRUARY 22–25
include Java SE and Java EE,
JavaLand MARCH 8–10 Voxxed Days Berlin BARCELONA, SPAIN
the inner mechanics of the
BRÜHL, GERMANY JANUARY 27–29 This industry-leading event
JVM, front end and web,
This annual conference is a gathering of BERLIN, GERMANY mobile, continuous delivery focuses on in-depth analysis of
Java enthusiasts, developers, architects, Sharing the Devoxx philoso- and DevOps, the IoT, cloud and present and future trends in the
strategists, and project administrators. phy that content comes first, big data, future and trends, mobile industry. The 2016 MWC
Session topics for 2016 include contain- Voxxed Days events see both alternative JVM languages, conference program features
ers and microservices, core Java and JVM internationally renowned and and agile development. tracks on the IoT, smart cities,
languages, enterprise Java and the cloud, local speakers converge. Berlin digital finance, and more.
DevNexus 2016
front end and mobile, IDEs and tools, and topics include Java compo-
Embedded World 2016
the Internet of Things (IoT). After lectures nent design with Spring 4.3; FEBRUARY 15–17
FEBRUARY 23–25
on the first day of the conference, attend- microservices with Java, Spring ATLANTA, GEORGIA
NUREMBERG, GERMANY
ees get exclusive use of Phantasialand and Boot, and Spring Cloud; DevNexus is a conference
The 14th annual gathering of
its rides and attractions. and simple REST APIs with drawing 1,700 developers, with
embedded system developers
Dropwizard and Swagger. 6 workshops, 12 tracks, and 120 08
PHOTOGRAPH BY RACHEL TITIRIGIA/FLICKR
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//events /
QCon London jDays
MARCH 7–9 MARCH 8–9
LONDON, ENGLAND GOTHENBURG, SWEDEN
QCon is designed for techni- jDays is a Java developer con-
cal team leads, architects, ference covering Java/Java EE,
engineering directors, and architecture, security, DevOps,
project managers who influ- cloud and microservices, testing,
ence innovation in their teams. JavaScript, IoT trends, methodolo-
Topics include what to expect in gies, and tools.
Java 9 and Spring 5, containers
CITCON
in production, microservices for
LATE MARCH (DATE TO BE ANNOUNCED)
mega-architectures, full-stack
PERTH, AUSTRALIA
JavaScript, and data science and
machine learning methods. CITCON, the Continuous Integra-
tion and Testing Conference, is
EclipseCon 2016
a worldwide series of free “Open
will explore the latest develop- Testing Java EE Applications Using
MARCH 7–10 Spaces” events for developer-
ments, define trends, and once Arquillian, by Reza Rahman, and
RESTON, VIRGINIA testers, tester-developers, and
again present the key areas of Hybrid Mobile Development with
EclipseCon is all about com- anyone else with an interest in
focus for future developments. Apache Cordova and Java EE 7, by
munity. Contributors, adopters, continuous integration and the
This is where hardware, soft- Ryan Cuprak.
extenders, service providers, type of testing that goes along
ware, and system development
Riga Dev Day consumers, and business and with it.
engineers come together to turn
MARCH 2–4 research organizations gather to
the next milestones of the IoT
RIGA, LATVIA share their expertise and learn Have an upcoming confer-
into reality.
from each other. Topics this year ence you’d like to add to our
This event is a joint project by
include an introduction to the listing? Send us a link and a
ConFoo Google Developer Group Riga, Java
Eclipse Che next-generation description of your event at
FEBRUARY 24–26 User Group Latvia, and Oracle User
Java IDE, hawkBit and soft- least four months in advance at
MONTREAL, QUEBEC, CANADA Group Latvia. By and for software
ware updates for the IoT, a faster [email protected]. We’ll
developers, Riga Dev Day focuses
ConFoo is a multitechnology con-
index for Java, and Java 9 support include as many as space permits.
on 25 of the most-relevant topics
ference for web developers, fea-
in Eclipse.
and technologies for that audi-
turing about 150 presentations
ence. Tracks include JVM and web
by popular international speak-
development, databases, DevOps,
ers. Past sessions have included
and case studies.
09
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