Say you have a URL that redirects to another (e.g., bit.ly). How do you find the real URL behind the redirect? You can do this in Java using the HttpURLConnection class. Like this: String url = "http://bit.ly/23414"; HttpURLConnection con = (HttpURLConnection) new URL(url).openConnection(); con.setInstanceFollowRedirects(false); con.connect(); String realURL = con.getHeaderField(3).toString(); You basically create a connection, disable […]

If you use an IDE like Eclipse to develop your Java programs then using external libraries is pretty straight forward. You just need to add the JAR file to your project and then right click on it and add it to the build path, and the IDE will do the rest of the work for […]

Below you’ll find the basic Regex patterns you can use to match, edit and replace strings. I am using the Java/Perl Regex flavor, so the patterns might be slightly different if you are using another programming language or platform. Java Implementation Here’s a simple Java sample that uses the Regex library. It will try to […]

Dining Philosophers is a problem about concurrent programming and synchronization, first proposed in 1965 by Dijkstra. Basically you have X philosophers sitting around a table, and there are X forks available (one between each philosopher). The philosophers do two things: think and eat (alternating between both). However, in order to eat the philosopher must grab […]

Below you’ll find a chronological order of some popular and/or important programming languages. 1840 – Analytical Engine Code The Analytical Engine was a theoretical (i.e., never built) mechanical general-purpose computer, created by British mathematician Charles Babbage. Ada Lovelace came across the idea, and created some code for the Analytical Engine. That’s why she’s considered the […]