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Display a string list in an Android ListView

Showing a list of items is a very common pattern in mobile application. This pattern comes up often when I make a tutorial: I often need to interact with data, but I don’t want to send a lot of time just on displaying that data when that’s not the point of the tutorial. So, what is the easiest way to ...

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Self-Signed Certificate for Apache TomEE (and Tomcat)

Probably in most of your Java EE projects you will have part or whole system with SSL support (https) so browsers and servers can communicate over a secured connection. This means that the data being sent is encrypted, transmitted and finally decrypted before processing it. The problem is that sometimes the official “keystore” is only available for production environment and ...

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NoSQL with Hibernate OGM – Part one: Persisting your first Entities

The first final version of Hibernate OGM is out and the team recovered a bit from the release frenzy. So they thought about starting a series of tutorial-style blogs which give you the chance to start over easily with Hibernate OGM. Thanks to Gunnar Morling ( @gunnarmorling) for creating this tutorial. Introduction Don’t know what Hibernate OGM is? Hibernate OGM ...

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Development Horror Story – Release Nightmare

Everyone has good stories about releases that went wrong, right? I’m no exception and I have a few good ones under my development career. These are usually very stressful at the time, but now me and my teammates can’t talk about these stories without laughing.                 History I think this happened around 2009. ...

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Java8 Lambdas: Sorting Performance Pitfall EXPLAINED

Written in collaboration with Peter Lawrey. A few days ago I raised a serious problem with the performance of sorting using the new Java8 declarative style. See blogpost here.  In that post I only pointed out the issue but in this post I’m going to go a bit deeper into understanding and explaining the causes of the problem.  This will ...

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Logging to Redis using Spring Boot and Logback

When doing centralized logging, e.g. using Elasticsearch, Logstash and Kibana or Graylog2 you have several options available for your Java application. You can either write your standard application logs and parse those using Logstash, either consumed directly or shipped to another machine using something like logstash-forwarder. Alternatively you can write in a more appropriate format like JSON directly so the ...

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Separating Integration Tests from Unit Tests Using Maven Failsafe & JUnit @Category

Why Unit Tests Should Run Separately From Integration Tests TDD at the Unit Testing level is fairly straight-forward, since classes in unit testing either do not have complex dependencies, or you mock-out the dependencies with a mocking framework (ex. Mockito). However, TDD quickly becomes difficult when we get to Integration Testing. Integration Testing is basically testing a component with some or all ...

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How to Translate SQL GROUP BY and Aggregations to Java 8

I couldn’t resist. I have read this question by Hugo Prudente on Stack Overflow. And I knew there had to be a better way than what the JDK has to offer. The question reads:               I’m looking for a lambda to refine the data already retrieved. I have a raw resultset, if the user ...

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Vagrant with Docker provider, using WildFly and Java EE 7 image

What is Vagrant? Vagrant is a simplified and portable way to create virtual development environments. It works with multiple virtualization software such as VirtualBox, VMWare, AWS, and more. It also works with multiple configuration software such as Ansible, Chef, Puppet, or Salt. No more “works on my machine”!   The usual providers are, well, usual. Starting with version 1.6, Docker containers ...

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