pragmatic dev

пример разумного и взвешенного подхода к разработке:
12 млрд реквестов в месяц за 120$ на java

Kotlin 1.0

Присматриваюсь к котлину
небольшое голосование: https://habrahabr.ru/post/277431/

must listen: Алексей Зиновьев — Java &Data Science

you can't debug lambdas until August 2015 =(

jdk bug (+jetbrains)

FIX in JDK 8u60 at Aug'15

"Дедлок без локов"

Для тех кто до сих пор считает хабр сборищем джунов со статейками про собственные велосипеды - очередное погружение в проблемы jvm от архитектора ОК с которыми мало кто до сир пор сталкивался в том числе сами авторы Java (David Holmes).

ultimate-stress: simple and fast stress-test framework

[russian version]

This post is about stress test framework mainly for java projects but can easily be used for others (from any machine with java7+), as there is a support for http requests with template engine out-of-box.

Algorithms and Data Structures of JDK 7

[russian version]

While checking periodically if there is one or another standard algorithm in JDK I've decided to make such index. It was also interesting why some famous data structures or algs are included in and others - not.
A format of this survey is only about key properties and features of algorithms and data structures of JDK, all details and full description - you can easily find in javadoc or jdk sources.
Let's start from simple to complex!

смотреть всем

особенно т.н. "архитекторам" и product/project-менеджерам... особенно в банках или госструктурах.
JUG.RU: Антон Кекс, Simple Pure Java (Как нам спасти Java?) +часть 2

p.s. конечно автор местами перегибает для красного словца, но в целом все по делу, из реального опыта, я видел подобный ад чуть ли не во всех местах где работал.

Final Parameters and Local Variables

The trend of marking parameters and local variables as "final" does not really enhance your code, nor does it make it more secure.

Why is Erlang slower than Java?

Why is Erlang slower than Java on all these small math benchmarks?

Despite many answers and interest the question is still open - why?

Erlang HiPE is also compiled to native, compact data types (not min 32/64 bit sizes as in java), no threading overhead (actors)... And still java7 is faster from x10 to x100 in that benchmarks.

Why? dynamic typing, slow GC or poor native compiling?

how-to-create-mutable-java-lang-string

2012, 17 years since java born: how-to-create-mutable-java-lang-string

ну дела...

такой баг нашли: http://stackoverflow.com/questions/10620680/why-volatile-in-java-5-doesnt-synchronize-cached-copies-of-variables-with-main

слабо верится что только сейчас всплыло ведь jsr133 вышла аж в 2004 году, думаю поломали просто.

faced gotcha

If you use osgi - you can't load property files from classpath as usial, +SO

Размеры массивов в Java

веселая арифметика: http://habrahabr.ru/post/142409/

ordered high throughput message monitor

Consider we have some high-throughput message listener, say processing more than 1000 messages per sec and there is a task to add some checks on each message like latency or correct ordering checks.

The task is quite common in remote messaging systems with failover functionality: e.g. you can miss a few messages when your messaging system is failovered or get stale ones due to some network issues or bugs in your messaging system itself.

Latency checks are OK - just compare operation between 2 timestamps eventually.

The problem is with ordering checks as surely we'll have some race-conditions here but using locks/synchronization will most likely kill performance and scalability.

So we need some kind of non-blocking algorithm - sure CAS atomics will help us.

Let's specify the requirements, we need:
-track for missed messages (when get forward ones)
-ignore the stale messages (when get old)

No more words, let's just code it:

groovy history

From Groovy creator (wikipedia): "I can honestly say if someone had shown me the Programming in Scala book by Martin Odersky... back in 2003 I'd probably have never created Groovy."

- quite funny, but still my choice is groovy, mainly due to its full interoperability with plain java )

Coolest RIA: smartgwt or not?

Considering GUI an effective RIA java app based on google app engine or other free java cloud hosting:

1. gwt gui library is very poor, even standart elements like datagrid - you'll have to expand to get simple things working (e.g. try to put image in a cell).
2. extgwt (gwtext) has one of the richest set of elements, but limitations with a license: you'll have to opensource your application if you use extgwt or pay.
3. vaadin - modern framework, but all things are handled on server-side, e.g. even onClick() handler. Extensive amount round-trips (commented details here).
4. jQuery/jQueryUI and other pure js frameworks - will force you programming with html/javascript/css besides java/groovy or what you are using on server-side. Do you know an cool IDE for all of that? )
5. ....
6. SmartGWT - analog extgwt with similar richest set of widgets and components with plain lgpl license (they sell only server-side java implementation)

Seems SmartGWT now is an optimal solution for gwt-based RIA where developer can concentrate on pure business logic w/o writing own datagrids, pagination and tuning html/css for different browsers.

jvm reordering tests

I was playing with java memory visibility and wrote a few tests for reordering. My examples break java safe publication idiom, so the jvm is free to reorder constructor instructions and object link initialization. But no reordering effect I've got so far, seems modern architectures don't allow it anymore