Articles

One of the most common functions we need as developers dealing with data is sorting--by being able to sort our data, we can optimize our algorithms to run much faster, and find the data it needs to in a fraction of the time that it would take to otherwise. As a quick thought experiment: imagine that you are...

The Java Map interface is a part of Java Collection framework, but it is not a subtype of the Collection interface. So it behaves in a different way compared to, say, Lists, or other collection Objects. Each element of Map represents...

Hi! When you studied multithreading on CodeGym, you frequently encountered the concepts of "mutex" and "monitor". Without peeking, can you say how they differ? :) If yes, well done! If not (this is most common), that's no surprise. "Mutex" and "monitor" are actually related concepts...

Hi! Today we'll talk about working with files and directories. You already know how to manage file contents: we've dedicated a lot of lessons to this :) I think you find it easy to remember a few classes used for these purposes. In today's lesson, we'll talk specifically about file management: creating, renaming, etc...

Java Hashtable class is one of the oldest members of Java Collection Framework. It is an implementation of mathematical hash table data structure. In Java hashtable internally contains buckets where the key/value pairs are stored. Hashtable is pretty similar to HashMap. The most significant difference between...

Hi! Let's talk about serialization. You probably remember that we've already had lessons on serialization. And so we did :) If you don't remember well how serialization works, why serialization is needed, and what tools Java has for serialization, you can run through these lessons. Today's lesson will be about...

Hi! In today's lesson, we'll talk about large numbers. No, I mean REALLY BIG. We have previously repeatedly encountered the table of value ranges for primitive data types. It looks like this...

Hi! When writing the lessons, I particularly emphasize if there is a specific topic that will be absolutely essential in real work. So, LISTEN UP! The topic we'll cover today will definitely come in handy in all your projects from day one of employment. We're going to talk about logging...

Hi! We're going to talk about generics. I must say that you will learn a lot! Not only this lesson, but also the next few lessons, will be devoted to generics. So, if you're interested in generics, today's you're lucky day: you will learn a lot about the features of generics. And if not, resign yourself and relax...

Hi! In today's discussion, we'll talk in detail about "phantom references" (PhantomReference) in Java. What kind of references are these? Why are they called "phantom references"? How are they used? As you'll recall, Java has 4 kinds of references...

Hi! Today we will introduce another data format called XML. This is a very important topic. When working on real Java applications, you will almost certainly encounter XML-related tasks. In Java development, this format is used almost universally (we will find out why below), so I recommend...

Hi! Today we'll consider a rather interesting topic: RMI. This stands for Remote Method Invocation. You can use RMI to allow two programs to communicate with each other, even if they are on different computers. Does that sound cool? :) And it's not so difficult to do! In today's lesson, we'll analyze the elements of the RMI...