“What’s a serialVersionUID used for?” “What if you do not define it?” These seem to be pretty popular Java interview questions. The second one builds on the top of the first. But, what’s more popular than these questions are the blog posts explaining what the right answer is. ...
Let’s say you want to execute some tasks. Since executing it through a single thread might take you quite some time to get the result, you decide to use the ever dependable ExecutorService to process it through multiple threads. ...
You heave a sigh of relief, as the QA has approved a long-awaited feature for deployment on Prod. However, as a part of the process, it is first deployed on the UAT env, where there are test accounts that can be used to certify the feature works outside of the local developer and QA testing systems. ...
Running specific commands with sudo using Ansible It seems a trivial use case, but it’s not. Consider a situation when you’re not the user allowed a full sudo access on the remote machine. However, you are only allowed the sudo access on certain commands, which, of course, requires a password. For example, starting or stopping a service. ...
We know about companies using Dark Patterns (more on this post by TechCrunch: WTF is dark pattern design?), and how they affect users. But can there be something like a “Stupid Pattern”? A thing that most companies do, and they don’t even realize it’s stupid? This blog post is a part real-life case study, and a major rant about one such pattern that is almost definitely, very stupid. ...
But can one even make Enums dynamic? Enums, by definition, are static. They are used to “predefine” constants. I’ll let the official Oracle Java Tutorial on Enums to help explain the definition. ...
How do you define and use constants in Java? Most advice on Internet has the following opinions: Declare public static final for constants in a class Do not use Interfaces for constants The most common way to define a constant is in a class and using public static final. One can then use the constant in another class using ClassName.CONSTANT_NAME. Constants are usually defined in upper cases as a rule, atleast in Java. ...
I wrote this earlier on a Github gist, but putting it here for a consolidated reference. Want to change Java Version/JAVA_HOME for Ant builds? Open ~/.antrc file by running vim ~/.antrc Add JAVACMD=<NEW_JAVA_HOME>/bin/java and save The Ant wrapper script for Unix will source (read and evaluate) the file ~/.antrc before it does anything. On Windows, the Ant wrapper batch-file invokes %HOME%\antrc_pre.bat at the start and %HOME%\antrc_post.bat at the end. You can use these files, for example, to set/unset environment variables that should only be visible during the execution of Ant. ...
A couple of weeks ago, I was tasked with figuring out a way to enable two way SSL. I am a programmer, and have had only a limited experience with networking concepts like SSL/TLS in my short career. So I turned up blank on how I could make it possible. Moreover, the terminology you’d find online is not uniform. From a programming point of view, the term “Two way SSL” led me to limited results, and I soon realized that other communities have different terminology. For example the “Two way SSL” is also known as “Mutual TLS” or “mTLS” or “Client Certificate Authentication” in Cloud/DevOps communitites. This makes finding the right resources online more difficult. ...
Yes, you read that right. To give you some context, some time ago, our (my org’s) Redis usage was un-tracked – meaning we didn’t know why our Redis memory was being occupied as much as it was. Our 2.5GB of Redis ElastiCache was almost close to being full, and if it somehow reached its limit, our system would start to fail. Though there were fallbacks in place, Redis could turn out to be a bottle-neck. ...