Solid Foundation! Starting Java Intensively Part 3 (Part 2): Sockets and File I/O

From TCP/IP to HTTP! This lecture is for those who lack basic network theory and want to understand major theories by memorizing them. You can do it!

Are you lost while learning web development? I'll help you find your own way. Even if you're not from a computer science background, you can understand how web service architecture works through a short 1-hour lecture.

This lecture guides those who have learned the basic course of network core theory by memorizing it to understand theories in more depth. It covers more in-depth theories such as NAT technology, the operating principle of Internet routers, load distribution system principles, and VPN technology principles. The goal of this lecture is also to finish it by memorizing it! You can do it!

This is a C language programming course for those who want to become professional developers rather than hobbyists. I recommend it to those who want to learn by writing and reading and go down a sweet path!

Secrets to Escaping Beginner Status Revealed! We'll properly teach you about Java multithreaded programming and synchronization techniques!

Based on an understanding of Reflection and Annotations, it helps you clearly understand how the Spring framework operates!

This is a lecture for all non-major beginners who want to become computer science majors by memorizing broadly and shallowly. You can quickly learn what you can learn in essential computer science major subjects such as computer architecture and operating systems. Above all, you can finish it by memorizing it!

This lecture comprehensively organizes the content that would be good for those who want to get a job as a new Spring Java backend developer, especially those who are about to have an interview.

I'll show you how Java backend developers using IntelliJ can maximize productivity with Claude Code. I'll especially help those using Windows environments completely solve vibe coding environment issues.

If you have studied the C language thoroughly and studied linear data structures, it is now time to experience the world of object-oriented programming with C++!

We enable you to fundamentally understand and resolve issues where Hangeul appears broken on web pages or in databases, or files contain unknown characters.

We will help you memorize and finish the encryption technology responsible for the security of the Internet very easily. You can understand the structure and principles of various technologies such as SSL certificates, PKI technology, digital signatures, and public authentication systems.

For those aspiring to be Java-based Spring backend developers, to easily secure a job, we learn Java properly! Rigorously!

This course is for those who want to develop packet analysis programs like Wireshark and various network solutions using the Npcap library.

It covers just two things properly: object-oriented programming and the JVM! Plus, it throws in linked-list-based linear data structures.

This book contains only the essential techniques for those developing Windows OS-only applications using MFC.

This is a course provided to those who have completed the course 'Learn broadly and superficially to become a computer science major' so that they can study the operating system in more depth.

A must-take course for anyone thinking of becoming a Windows programmer! Have you studied C/C+, data structures, and operating system theory? If so, studying system programming is the answer now. Now it's time for practice!

In this lecture, you will learn application-level protocol design techniques and how to develop a high-performance server based on IOCP!

This course covers topics for those who have completed basic studies of the C language, such as compiler theory, stack frame structure, multi-threading, virtual memory structure, security vulnerabilities, and secure coding. It is highly recommended for those who wish to become experts in the C/C++ field, or those who majored in CS or have similar skills!

We will refactor a web application built with Java + Spring Boot to Kotlin + Spring Boot and implement additional requirements. In the process, we will use Junit5, SQL, JPA, and Querydsl, and cover the pros and cons of various methods from the design and implementation perspectives.

We will develop a scalable order processing system capable of real-time event streaming using Spring Boot 3.x + Kotlin to build a Kafka cluster, leveraging PostgreSQL CDC with Debezium Connect and Apache Avro schema.

It covers just two things properly: object-oriented programming and the JVM! Plus, it throws in linked-list-based linear data structures.

For those aspiring to be Java-based Spring backend developers, to easily secure a job, we learn Java properly! Rigorously!

This is the first lecture of Clean Spring, a lecture series designed to allow a hypothetical startup development team to experience, in a manner similar to actual work processes, the process of developing quickly, stably, flexibly, and with good maintainability by incrementally following Clean Code and Spring development principles. By utilizing Domain Model Pattern and Hexagonal Architecture, you can acquire necessary skills and development strategies in the domain-centric initial development phase.

This is a course where you create a mini RPG 2D game to learn 2D development techniques, and then learn the process of converting the completed game into a network game by transitioning it to Netcode for GameObject. It covers various essential tilemap functions for 2D games, and is designed to naturally help you learn clean code writing techniques that adhere to SOLID principles. Additionally, this is a lecture that builds the foundation for network games using the updated Netcode API in the latest Unity 6 version.

This course covers core computer science knowledge such as networking, multi-threading, and operating systems, and teaches MMORPG technology by building a game server from the ground up. It provides a comprehensive overview of the knowledge that a new server programmer should know, building a foundation that allows them to adapt to any project without feeling overwhelmed.

We enable you to fundamentally understand and resolve issues where Hangeul appears broken on web pages or in databases, or files contain unknown characters.

Have you ever had a hard time because you didn't understand IT infrastructure (server, network, storage, etc.) technology? Do you want to understand how IT infrastructure is structured and what technologies are applied? This is the only lecture in Korea that explains the various technologies that make up IT infrastructure!

This is a course where you study core computer science knowledge such as networking/multithreading/operating systems and learn MMORPG technology by building a game server from scratch.

Learn SAGA transaction management techniques for maintaining data consistency in distributed environments through hands-on practice. Configure three microservices using Spring Boot and Docker, and implement both Orchestration and Choreography patterns with Kafka and MySQL. Through this course, you can master core concepts that are immediately applicable in real-world scenarios, including distributed transaction operation principles, compensating transaction design, and failure recovery handling.

Learn Java-based data structures and algorithms, and grow into a competitive coding expert with practical problems!

This is a basic DFS lecture that explains the way a liberal arts major and working developer studied to get a job :) We have prepared a lecture where you can learn by solving problems yourself, with minimal boring theory lectures! After taking this lecture, you will be able to solve silver level DFS problems on your own according to Baekjoon standards.

Refactoring is one of the basic skills that a software engineer should have. This course is designed to explain and practice various code smells and refactoring techniques in a more practical way using IntelliJ and Java.

This course covers the essential knowledge that every 0.5 to 3-year C# application developer should have.

IntelliJ IDEA Conf 2025 is an annual online conference hosted by JetBrains that provides valuable sessions for Java and Kotlin developers. It covers various topics including AI adoption, Spring Boot, Gradle, Kafka, and database management, while also sharing insights on cloud integration, secure coding, developer performance improvement, and advanced development techniques. This conference is accessible to both professional and beginner developers, offering opportunities to learn about the latest technologies along with productivity tips for writing high-quality code more efficiently.

This is a full-stack hands-on course where you'll clone ChatGPT and implement everything from scratch. From Spring Boot server to React frontend! This isn't just a course where you follow along with code, but one that guides you to build a high-quality AI chatbot service through actual service deployment.

Spring AI + JPA + MySQL Premium Reservation Agent Backend Development with 'Autonomous Behavior' Beyond Chatbots to Agents: The Definitive Guide to Tool Calling and Prompt Engineering

Experience the power of Type Safe SQL with jOOQ!

Learn Springboot + ReactNative RestAPI Board Creation Faster Than Anyone Develop a CRUD server with Springboot and create your own board with ReactNative!