Spring Sessions allows you to persist user sessions into a database. Combined with Spring Security, it is easy to create a setup where each logged in user is represented by a row in a SPRING_SESSION table. Externalising sessions into a database is also a prerequisite for a zero-downtime deployment strategy where users can stay logged in while a new application version is deployed. On paper, the integration of those two Spring components is very easy. Assuming you have a working ...
Different deployment environments (e.g., development, testing, staging and production) often require that different pieces of code are switched on and off. For example, you only want to send real emails in production and write to an email log in all other environments instead. Or your code to initialise the database should only run in the staging environment. A simple but hard to maintain way for such conditional code executions is to define a globally available variable such as isProductionSystem and write ...
Stop repeating yourself. Emails and messages in general often consist of repeated content blocks that never change. Greetings and signatures are perfect examples: some people even try to eliminate such “noise” from messages (for example, the “nohello”-movement). While it is unrealistic that such changes to the human interaction protocol will ever be universally accepted, there is something else a productivity-minded person can do in order to lose less time each day typing the same phrases over and over again. Outlook ...
Measuring code execution times is hard. Learn how to eliminate systematic and random measurement errors and obtain more reliable results. We often need to measure how long a specific part of code takes to execute. Unfortunately, simply measuring the system time before and after a function call is not very robust and susceptible to systematic and random measurement errors. This is especially true for measuring very short intervals (< 100 milliseconds). Systematic and Random Errors So what is wrong with ...
Question: In my Thymeleaf template, I want to output the size of a list of objects. For example, for the list List<String> list = Arrays.asList("Go", "Python", "Scala"); the result should be 3. How is this possible using just Thymeleaf syntax? You can use the following expression: <span th:text="${#lists.size(myList)}">[Number of Elements]</span> And just in case you want to check if the list is empty, there is also an easy method for that: <span th:if="${#lists.isEmpty(myList)}">This list is empty</span> ...
Atlassian’s collaboration tools Jira and Confluence are one of the most popular tools for managing software projects and group knowledge. Learn how to get access to these great tools for free. For the longest time, Atlassian charged 10$ per month per application in their “Standard” tier. While this is basically nothing for an established company, it is still discouraging for start ups and non-profits since it sums up to a bill of 240$ per year for the popular combination Jira ...
GitLab offers to create personal access tokens to authenticate against Git over HTTPS. Using these tokens is a secure alternative to storing your GitLab password on a machine that needs access to your repository. It is also the only way to automate repository access when two-factor authentication is enabled. However, GitLab does a poor job documenting how you actually use these tokens. Create an Access Token Navigate to “User Settings” > “Personal Access Tokens” and enter a name and, optionally, ...
In many git workflows, all changes to your code should eventually end up in the master branch. You may also have a develop branch which contains code changes that are not ready for production deployment yet. For some reason or another, you may end up in a situation where your develop has changed so much that you can no longer easily merge it into master. Most of those reasons suggest bad practices, but such a situation may also arise due ...
Oracle is currently offering an always free tier of its compute cloud. In this article, I will show how to register an account, add the free tier units and connect to them via PuTTY on Windows. What is included? While the offer is actually free for an unlimited time, the following restrictions apply: 2 database services are included (ATP serverless and ADW) limited to 1 OCPU and up to 20 GB 2 compute services (1 GB RAM and 1/8 OCPU ...
Directed Acyclic Graph (DAG) style dependencies between individual stages in a continuous deployment pipeline allow for a more flexible workflow and better utilize available computational resources. Imagine a simple pipeline consisting of three jobs: A syntax check A code complexity check Running all unit tests You may be tempted to group those in two stages: A) Build (consisting of jobs 1 and 2) and B) Test (consisting of the unit tests): Traditional Sequences In plain old GitLab pipelines, you would ...