Caching is an essential to the majority of web applications. Let’s face it: most of the work done in an average web application (especially public ones) is repetitive, either the same user requesting the same information multiple times, or multiple users requesting the same information. The question is always: “How long do I cache”? We […]
ANWB Big data Proof of Concept
At the ANWB people are constantly trying to improve the services they provide. One of these services is to provide traffic information. In the Netherlands the National Data Warehouse for Traffic Information (NDW) provides an enormous database of both real-time and historic traffic data. This data comes from many different sources and is available as open […]
Integrating Flyway In A Spring Framework Application
This post is about how to integrate Flyway into a Spring/JPA application for database schema migration. To skip all the preambles and get straight to the instructions, jump to Project’s Dependencies Set-up Flyway is a database migration tool which helps do to databases, what tools like git/svn/mercurial does for source code…which is versioning. With Flyway you […]
How to Remotely Debug Application Running on Tomcat From Within Intellij IDEA
This post would look into how to tackle and debug issues in scenarios where they only occur in production (or other remote environment) but not in development environment. As anybody who has been in this kind of situation would acknowledge, trying to pinpoint the cause of these kind of “issues” might quickly end up being […]
Dynamic web forms with AngularJS
When we’re building web applications containing data entry forms, it’s sometimes a requirement that (part of) the form is dynamic, in the sense that the fields to be included in the form need to be determined at runtime. For instance, this may be required if application managers need to be able to add new data […]
Web forms with Java: AngularJS and other approaches
After learning about AngularJS a couple of months ago, I started using it on new Java web projects, and that has been a great pleasure. If you haven’t worked with AngularJS yet, you may be wondering what the hype is all about and whether or not it’s a thing worthwhile of investing your time in. […]
Session Timeout and Concurrent Session Control with Spring Security and Spring-MVC
A web application me and my team are building recently underwent a security review. As usual, because you haven’t yet had time to put any real effort into it, some security risks did surface. We use Spring Security and Spring-MVC and I will talk about implementing a session timeout and concurrent session control: nice subjects […]
Java clients behavior during a split-brain situation in Elasticsearch
In my previous blog post I explained what the split-brain problem is for elasticsearch and how to avoid it, but only briefly spoken about how it manifests. In this post I’m going to expand on what actually happens to your indexing and query requests after the split-brain has occurred. As I’m sure you’re already aware, […]
Using Docker to efficiently create multiple tomcat instances
In my previous blog article I gave a short introduction into Docker (“an open-source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere”). In this article we’ll check out how to create an image for Tomcat 7 and the Java 7 JDK as dependency. So, let’s […]
Checking return values in Java
The other day I made a stupid coding error. It took me the better part of an hour to track it down. We all have those moments. Blame it on a bad night’s sleep, a brain fart, or perhaps the fact that your colleague at the next desk has been whistling that tune from Gotye’s […]