Fix : Ubuntu Boot error – Boot device not found (after partitioning)
Problem: Ubuntu gives the message “Boot device not found” after partitioning using Gparted (done from a usb instance). Reason : Unknown. Could be that no partit...
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.
School TimeTable Creator
School timetable creator is a program to create Timetables for schools written in C++. The features are – Allows for manual setting of class teachers. Checks wh...
Hibernate calls hang after giving message “opening JDBC connection”
Bug: Hibernate calls hang after giving the message “opening JDBC connection” in the logs. No exception/error message is thrown. Reason: Connection timeout not s...
Hibernate Gives Connection Pool Error: Timeout waiting for idle object
Bug: Hibernate connection times out (after the maxWait duration set for the datasource), and gives error message in the log – “Timeout waiting for idle object” ...
ClassCastException for same class on slim3 for Google App Engine
Bug: A class cast exception like the following is thrown – class x.y.z.MyClass cannot be cast to class x.y.z.MyClass Reason: The class loaders for both these cl...
jqGrid cell data disappears on clicking other cells
Bug: jqGrid cell data in a previously edited cell disappears on editing other rows. This usually occurs after a cell or row value is edited programmatically. Re...
UTF-8 encoding on J2EE
A 3 step method to apply UTF-8 encoding to J2EE applications. 1. Add the following directives to the page included in ALL jsps. <%@ page contentType="text/ht...
AirRaid
An MS DOS game where you shoot opponent fighter plane and save yourself from incoming missiles 😉 Download code here. (Note/Disclaimer : Last successful compilat...
Brikz
A simple brick game written in C++ Download code here. (Note/Disclaimer : Last successful compilation of most of the programs in this category were done from 20...
Mines
A minesweeper game programmed in C++. Download code here. Update, August 2026 — this download was lost when the site went down. Neither the source code no...