Impressions from
Geecon 2014
Vytautas Dagilis ir Adomas Greičius

More informtion you can find in
http://2014.geecon.org/schedule.html

The 7 Duties of Great Software
Professionals
Jurgen Appelo

Motivate yourself

Direct yourself

Educate yourself

Measure Yourself

Connect yourself

Brand Yourself

Improve yourself

How to get your kids started with Java
programming?
Arun Gupta
Scratch http://scratch.mit.edu/projects/23705523/
ALICE http://www.alice.org
GreenFood
BludeJ http://www.bluej.org/
Lego Mindstorms

Go language
Functional programing languge
Has interfaces but do not have objects
Made for cloud
Has its own compiler for many platforms

Mutation Analysis
or What Code Coverage Doesn't Test
Gleb Smirnov

Does code coverage shows
something?

Mutation Analysis judges the judges
1. Run the tests
2. Change the sources
3. Run the tests again
If a change is not making any test fail, the line is not covered

Some Mutation samples
● Negated conditional
● Mutated return of Object value
● Removed Assignment to member variable
● Conditionals boundary: < changes to <=
● Math: change operators (e.g. + to -)
● Remove void method call
● …

There are few java libraries...
● Javalanche
● Jumble
● Jester
Some are abandoned, outdated, slow or do not support framework...

Then there's pitest aka PIT
● Actively developed
● Acceptable performance
● Open Source
● Supports Java 8, Gradle, JUnit, *Mock* etc.

Everything You Were TaughtAbout Java Is Wrong
Tim Boudreau
Java bean is designed for UI
Application Servers are a Historical Relic
Threads for I/O? Really?
java.util.not-so-concurrent

Lukas Eder
Get Back in Control of Your SQL

NoSQLfor Big Data?
Lukas Eder
Get Back in Control of Your SQL
●
You’re giving up on ACID
●
You’re giving up on type safety
●
You’re giving up on standards
●
You’re giving up on tooling
●
You’re giving up on relational algebra
●
You haven’t asked operations
●
You don’t actually have «Big Data»

jOOQ
Lukas Eder
Get Back in Control of Your SQL

Jasmine Automated Tests for
JavaScript
Hazem Saleh

Arun Gupta
50 new features of Java EE 7 in 50 mins
http://s3-eu-west-1.amazonaws.com/presentations2
014/70_presentation.pdf

Test-Driven Development: That's not
what we meant
Steve Freeman

Advices
● Write readable code
● Test Interfaces, not internals
● Test protocols, not Interfaces
● From simple to general (do not overgeneralize from the start)
● Test at the right level

“It’s about explaining the domain, not
about proving the correctness of the
code.”
© Andrew Parker

Why does TDD work?
● Focused
● Concrete
● Empirical

Seven Ineffective Coding Habits of Many Java Programmers -
Kevlin Henney
Noisy Code
Comments
Lego Naming
Unencapsulated State
Getters and Setters
Uncohesive Tests
Underabstraction

Tom Bujok
33 things you want to do better
Lombok
Guava
Lambdaj
SLF4J
Spock
UNITILS
JUNITParams
AwaitTility
ByteMan
Groovy
Gradle

The Practical Implications Of
Microservices
Sam Newman

Where to standartise?
● Interfaces
● Monitoring
● Deployment

Fabric lib for deployment
(Python)

Nikita Salnikov-Tarnovski
I bet you have a memory leak
●
The most common leak in web applications
●
After application undeploy classes are not longer
needed
●
If even 1 class is left behind, he keeps all his friends
●
After some redeploys, you crash
Classloader
leak
https://www.youtube.com/watch?v=iHTg5QQg2NE

Beyond Error Handling
Michael Feathers

Passing Nulls

Error handling mechanisms
● Error return codes
● Error monads
● Exceptions

Exceptions are the solution to a problem we
shouldn’t have - distance between detection and
resolution

Remarks
Tell, don’t ask principle
Replace Type code with subclasses
Noticeable Error Handling is a Symptom of Bad Design
Consider ALL the cases to make design better

Reaction to an Error
● Fail fast
● Carry On - record
● Ignore - record