Spring boot : Testing Cassandra Repositories using Cassandra Unit
This short tutorial is about getting test classes running for the Cassandra repositories in a Spring boot application. The example provided uses Maven, Spring-d...
Author: Sreekumar Kj
Sreekumar (KJ) has been a hobby programmer from school days. Codemarvels is his personal blog from the year 2010, where he writes about technology, philosophy, society and a bit about physics.
He now runs a conversational AI company - DheeYantra - focusing his efforts to help businesses improve operational efficiency using digital employees powered by AI.
Spring boot application : local URL doesn’t load in an IFrame
Problem : Application URLs (local urls) not loading in iframe inside an application UI. Reason : Spring sets the X-Frame-Options to Deny by default. Fix : Allow...
How to show custom favicon in Vaadin UI ?
Add this custom Vaadin servlet to show a different favicon (other than the Vaadin default) in your UI application – [java] import com.vaadin.server.*; import co...
A Javascript hack for Mohanlal-Rekha puzzle
Click on any node to find Mohanlal’s relation to that person (default selection is actress Rekha). Disclaimer : Based of the Whatsapp forward* only, which is gi...
Openfire does not listen to port 5222
Problem : Openfire server does not listen to port 5222. Symptoms : netstat -tulpn | grep LISTEN – will not show ports 5222 or 5223. tail -1000 /opt/openfire/log...
Precedence and best practices for Apache ProxyPass
To set priority/order of ProxyPass (and ReverseProxyPass) rules, write the one with most precedence above the rest, and so forth. Delete any non-dot-confs (.co...
Open port 80 for Apache2 on Ubuntu using the Ubuntu firewall service
For cases where Apache2 is available within the box/local host, but not from LAN, you might have to open port 80 in the firewall. This is a simple command for t...
Extract a selected polygon from an image to a new image file in Java
A reference code to extract a selected shape (this case polygon, could be another shape like Rectangle) – [java] BufferedImage in = ImageIO.read(new File(source...
Torch installation fails with message “Error. OpenBLAS could not be compiled”
Problem : Torch installation fails to install dependencies (“bash install-deps”) with the message “Error. OpenBLAS could not be compiled” Reason : gfortran depe...
Fix : No sound on Ubuntu (16.04) after a Bluetooth audio device power off.
Problem : After Bluetooth speakers were abruptly switched off, Ubuntu 16.04 on Alienware (17 R2) stopped producing sounds on its analog sound card. Reason : Dou...