00 Learn Netty Well, It Is the Essential Path to Cultivate Your Java Prowess

00 Learn Netty well, it is the essential path to cultivate your Java prowess #

Hello, I am Ruodi. I used to work as a technical expert at Meituan Dianping and I am a high-performance component enthusiast. I usually focus on the development of infrastructure middleware and have accumulated rich experience in distributed architecture design and optimization.

We all know that the network layer is a crucial part of architectural design, but there are many Java network programming frameworks available (such as Java NIO, Mina, Grizzy). Why am I recommending Netty here?

Because Netty is currently the most popular high-performance Java network programming framework. It is widely used in middleware, live streaming, social networking, gaming, and other fields. Currently, many well-known open-source software use Netty as the underlying framework for network communication, such as Dubbo, RocketMQ, Elasticsearch, HBase, etc.

Why should you learn Netty? #

You might ask, if my work doesn’t involve much network programming, do I still need to spend time learning Netty?

In fact, in interviews for mid to senior-level Java development positions at major internet companies (Alibaba, Tencent, Meituan, etc.), they often ask questions related to the core technical principles of Netty, such as:

What aspects of Netty contribute to its high performance? How does it inspire your project development?
What are the important components of Netty and how are they related to each other?
How are Netty’s memory pools and object pools designed?
Can you provide any impressive system optimization cases related to Netty?

These questions may seem simple, but if you don’t have a deep understanding of Netty, it’s easy to “stall” when answering them. I have interviewed many job seekers, and even though they have some experience with Netty, when it comes to discussing technical details and practical problem-solving in projects, most of them only have a superficial understanding of Netty and its technical principles. If you can learn Netty well and master the underlying principles, it will definitely be a bonus in your job interviews.

Furthermore, through learning Netty, you can also enhance your programming thinking and have a comprehensive understanding of other knowledge systems in Java.

When I first started working, my first task was data collection and reporting. I tried various solutions, but they were all rejected by my supervisor who said, “Don’t make it so complicated, just use Netty directly.” So I learned Netty while completing the task and even made time to study the Netty source code.

Looking back at the days when I studied the source code, although it was tough, it seemed to open the door to a new Java world for me. When I understood the design principles behind Netty, I had a sudden realization about concepts that were difficult for me to comprehend at the time, such as I/O models, memory management, thread models, and data structures. And when I later studied other excellent frameworks like RocketMQ, Nginx, Redis, etc., I clearly felt that the learning process became more convenient and efficient.

Therefore, if you want to improve your technical skills and find a satisfactory job, learning and mastering Netty is very important. In fact, in your day-to-day development work, Netty’s ease of use and reliability greatly reduce the cognitive burden on developers.

During my student days, I wrote many network applications, which now seem excessively lengthy. When I became proficient in Netty, all these problems were easily solved. Netty provides advanced encapsulation for Java NIO, simplifying the development process of network applications. We no longer need to spend a lot of effort on complex APIs such as Selector, SocketChannel, ServerSocketChannel, etc.

When I wrote network applications on my own, I had to consider a series of problems such as packet fragmentation/reassembly, data encoding/decoding, and TCP reconnection. But now Netty provides ready-made solutions for us. In addition, if you encounter any problems, you can discuss them in the community. Netty has short iteration cycles for bug fixes, and its reliability and robustness are increasingly recognized and adopted by more companies.

Frankly speaking, Netty’s existence allows Java to stand shoulder to shoulder with C++ in the field of network programming.

Based on the above, I want to learn Netty together with you. I hope to provide help for you in your work and job search, and open up your learning path.

Learning goals and difficulties #

So how should we learn Netty technology? As a beginner, you must have many questions or encounter some problems:

Lack of basic knowledge related to networks, leading to a shallow understanding of Netty and difficulty in applying it;
Netty has a wide range of knowledge points, and online resources are scattered. The community documentation is not friendly enough for beginners. How to systematically learn Netty;
Even after learning the basic theory of Netty, you still don’t know where to start when it comes to project development;
The Netty source code is too complex, making it difficult to get started and grasp the key points, ultimately leading to giving up halfway;
Lack of practical experience in work, and only studying theoretical knowledge, which is easy to forget. During the learning process, I also encountered the same problem. Fortunately, my work experience at Meituan gave me a lot of opportunities to practice and solve problems. During this period, I gained new insights into system design.

Here, I would like to share some of my learning experiences for you to learn together. These learning methods are not only suitable for Netty, but also for other technologies. I hope that through these experiences, we can progress together.

First of all, interest is the best teacher. After work, I will allocate at least 10% of my time to thinking and learning new knowledge. I won’t miss out on such excellent learning resources like Netty.
Secondly, if you lack project experience at work, don’t worry too much. You can try to implement some MVP prototype systems, such as RPC, instant messaging (IM), HTTP servers, etc. Don’t think that this is a waste of time. Practice leads to true knowledge, and while learning Netty, you will also gain a lot.
Additionally, before studying the source code, it is important to become a skilled worker and master the basic theories. In fact, no matter what framework you are learning, I would try to challenge myself first. I would ask myself in my mind, “How would I design its architecture?” Then I would learn related blogs, source code, and other resources, and think about why the author’s design is completely different from mine. What are the differences between the two designs?
Finally, repeated learning is also important. Sometimes, when absorbing new knowledge, new ideas may arise regarding previously understood knowledge points. I would relearn the relevant knowledge with questions in mind in order to gain a deeper understanding. Regularly gain new insights.

Learning Path of Netty #

If you are currently:

Having a certain foundation in Java and needing to dive deep into studying an open-source framework to improve your abilities and broaden your horizons;
Hoping to increase your shining points in job interviews and become an expert in Netty;
Wanting to systematically learn Netty server development and deepen your understanding through practical experience;
Engaged in networking, distributed service frameworks, or other related work and aspiring to become an expert in this field.

Then this course is tailor-made for you. In this course, I will analyze Netty’s core technical principles starting from the source code, combined with high-frequency interview questions. At the same time, I will share with you some programming concepts and practical experience that have benefited me greatly over the years, helping you apply what you learn in your work and avoid pitfalls.

Here, I have also summarized a mind map of Netty’s core knowledge points, hoping to help you organize the overall knowledge structure of this column. I will guide you step by step to establish a complete Netty knowledge system, solidify your Netty basic knowledge, advance your Netty skills, and gain practical development experience.

Solidify Netty basic knowledge: In the first and second parts, I will introduce the overall picture of Netty, understand Netty’s development status and technical architecture, and explain the principles and usage of Netty’s core components one by one, as well as essential coding and decoding skills necessary for network communication, laying a foundation for the subsequent code analysis and practical sections.
Advance Netty skills: In the third part, I will explain Netty’s memory management and hope to help you make analogies through a comparison with two famous open-source software, Nginx and Redis. In the fourth part, combined with high-frequency interview questions, I will quickly and accurately help you understand the high-performance technical principles of Netty by analyzing the core source code, and apply the design ideas within.
Practical development experience: In the final part of the course, I will guide you to build a high-performance distributed RPC framework from scratch, and help you master network programming skills and deepen your understanding of Netty by focusing on the key points of the RPC framework.

In addition to the above content, you can also gain some extra benefits from this column.

Rome wasn’t built in a day. The course will intersperse essential Linux network programming knowledge to help you achieve more with less effort in understanding Netty.
Debugging experiences and techniques for Netty source code. We can learn excellent design ideas and techniques from the source code.
What pitfalls have been encountered in actual project practice with Netty? What are the best practices?
How to quickly build a high-performance distributed RPC framework using Netty? I will guide you step by step to complete this MVP prototype.
How to upgrade and level up on the technical road? I will share with you how I learned and built my own technical system.

In conclusion, I believe that you are full of enthusiasm for learning Netty. So let’s unlock the skill of Netty together. Feel free to leave a message and communicate and discuss with me. I hope that you can master the technology of Netty and make your development practice and career development smoother and longer-lasting!