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Yearly Archives: 2019

Minimize turnaround times with Open Liberty’s dev mode

java-interview-questions-answers

I’ve uploaded a video in which I show how to reduce the turnaround times while writing Enterprise Java applications that are deployed on Open Liberty. The liberty:dev goal of the Maven plugin watches for file changes and applies the changes instantly, without the need to rebuild the whole deployment artifact. I’ll show how Open Liberty can keep running while we’re ...

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5 Questions Everyone’s Asking About Microservices (Question 2)

When discussing the development impact on existing applications while transitioning to microservices, there are five questions that keep popping up in one form or another. They are the same regardless of the size of the organization and seem to become part of strategy discussions later in the process as organizations move towards microservice architectures. These articles cover questions that everyone ...

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Checking What’s Thrown in Java Tests

Someone came up with the idea of using try and catch blocks in unit tests in Java: 1 2 3 4 5 6 7 8 @Test public void test() {    try {       callSomeCode();    } catch (Exception e) {       assertEquals("foo", e.getMessage());    } } The above is tempting, but doesn’t work. If the code under test didn’t throw, then no assertion would ...

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The Chameleon Function

In Doctor Who the character Kamelion was a robot which could take any form. The physical prop they used was allegedly very troublesome and only understood by its creator, who wasn’t around to help put it right. So to the Chamelion function … Consider this code: 01 02 03 04 05 06 07 08 09 10 11 12 13 14 ...

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The Final Word on “final”

In Java, overuse of final feels like SHOUTING. It’s outdated and inappropriate much of the time. Java and JavaScript This is mainly about the final keyword in Java, but my opinion on its counterpart const in JavaScript has changed slightly. That I can think that const is a good thing and final is a bad thing needs some unpacking. I ...

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5 Questions Everyone’s Asking About Microservices (Question 1)

java-interview-questions-answers

One of the joys of my role is that I’m often talking to customers (or potential customers) about their concerns, their plans, and their strategies for moving their business forward based on open source technologies. When discussing the application development impact on existing developed applications and transitioning to microservices there are five questions that keep popping up in one form ...

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JVM with no garbage collection

JVM community keeps on adding new GC and recently new one was added and it is called  Epsilon and is very special one. Epsilon only allocates memory but will not reclaim any memory. It might look like what is use of GC that does not perform any garbage collection. This type of Garbage Collector has special use and we will look ...

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Need driven software development using Mocks

Excellent  paper on mocking framework by jmock author. This paper was written in 2004 that is 18 years ago but has many tips of building maintainable software system. In this post i will highlight key ideas from this paper but suggest you to read the paper to get big ideas behind mocking and programming practice.  Mock objects are extension of ...

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Toil Arising From Alerting

Rising toil is a worry for all DevOps teams. The reasons from where toil arises are numerous. This makes it a very difficult problem to tackle, and nearly impossible to eliminate completely. Therefore the best strategy that teams have to tackle toil is to minimize them as much as possible. In this post, we go over some of the basics ...

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