[Escape from layoffs and successfully landed] If you find that there are bad signs in small companies, hurry up and learn!

Reader feedback : This year's wave of layoffs is a bit fierce, but there have been some bad signs in our company last year. Following Brother Xiaofu's blog , I have completed a lot of my knowledge, including: middleware, bytecode, DDD projects, design patterns and interview manuals, etc., and finally have a little bit of competitiveness. Get ashore in time for this wave of layoffs! may also have luck, keep working hard!

Technology is accumulated over a long period of time, not overnight, nor is it a collector of a bunch of useless materials. Only by following the hardcore account owners who are still coding on the front line and absorbing actual combat experience can they grow rapidly. - Look at the information written by the architect of Dachang, it's really fragrant!

• information includes : Java Face-to-face Manual, Re-learning Java Design Patterns (PDF), Hand Spring, Bytecode Programming, Data Summary from University to Graduation, Lottery Distributed Spike Sweepstakes Practical Project - All the good stuff is out!
• Learning address : https://bugstack.cn

Valuable dry goods information introduction

1 Java Face-to-face Manual

• The book has a total of 5 chapters and 29 sections, 417 pages and 115,000 words, and took 4 months to complete. Covers data structures, algorithm logic, concurrent programming, JVM, resumes, and interviews with big Internet companies.

"Java Face-to-face Manual" is a PDF book that uses interview questions as the entry to explain the core Java technology. The content of the book also strongly proves to you that the code is a concrete realization of mathematical logic. Why does say that? When you read the book carefully, you will find that there is a lot of mathematics here, including: perturbation functions, load factors, zipper addressing, open addressing, Fibonacci hashing, and the use of the golden section point, etc. Wait.

Coding is only after the specific implementation of the R&D design is determined, and the design part includes: data structure, algorithm logic and design patterns, etc., and this part of the data structure and algorithm logic is fully reflected in the core API of Java. So, that explains why these topics have become hot interview questions, although we may all feel that such interviews are like building rockets.

2 Re-learning Java Design Patterns - PDF Version

• The book has a total of 22 real business scenarios corresponding to 59 sets of case projects, and compiled a PDF of 180,000 words and 271 pages. It took 50 days to complete.

This book is a practical book of Java design patterns written by the author, Xiao Fu, based on real cases on the Internet. The whole book takes the solution as the core, extracts 22 real scenarios such as transaction, marketing, rule engine, middleware, and framework source code from the actual development business, and conducts a comprehensive and thorough analysis of the design pattern. Help readers use various design patterns flexibly, deal with complex and changing business requirements calmly, and write code structures that are easy to maintain and expand.

3 byte code programming

The book has a total of 107 pages, 117,000 words, 20 chapters covering the use of three bytecode frameworks and JavaAgent and comes with a complete set of case source code!

To be fair, there is very little systematic knowledge about bytecode programming on the market and online searches, mainly because most developers rarely touch this part, including; ASM, Javassist, Byte-buddy and JavaAgent, there is not a lot of information without a large market. But everyone has actually used it from other frameworks or middleware, just like you used; Cglib, chaos engineering, non-intrusive full-link monitoring, and have you used jetbrains-agent.jar for an experiment?

4 Spring Hands-on Column

After writing part of the face-to-face content about Spring's core source code, I decided to start a Spring. Why do you do this? Because all the content I want to write, I hope it will be learned in a way that aims at understanding scientific thinking, rather than memorizing it by memorization. The content analysis of each Spring source code involved in the process of writing the scriptures will still appear very large even after removing some non-mainstream logic.

This column is a book to develop a simplified version of Spring to learn its principles and knowledge content. It not only focuses on code writing and implementation, but also pays more attention to demand analysis and solution design on the content. Debug the corresponding code. In the process of reading, fans should not be afraid of encountering problems in the process of learning, these are normal! I hope you can always insist on learning these contents by yourself and by yourself, come on!

5 IDEA Plugin Development Manual

This development manual is divided into 4 chapters and 12 sections step by step through practical case development, connecting various common technical points developed by IDEA Plugin, and explaining how to develop an IDEA plug-in for readers.

IDEA plug-in development can help developers improve energy efficiency and solve common problems in some practical scenarios. However, when I was developing IDEA plug-ins recently, there was really not much information on the market, and there was no complete development instruction manual, so I encountered a lot of things that I didn’t know, and I needed to search the source code a little bit and verify the API interface. , and finally realize the various functions, of course, there are indeed many pits in this process! Next, in this column, some knowledge about IDEA plug-in development will be output as case studies to help R&D partners in need to build IDEA Plugin together.

6. Lottery lottery system - four-tier architecture practice based on domain-driven design

Lottery lottery system project is an Internet lottery system for C-end crowd marketing activities, which can provide logic functions such as creation, participation, accounting, and awarding of lottery game play strategies. In the process of use, the operators create a lottery game for probabilistic prizes to attract new users, activate them, and retain them. Usually, such a system will be used in various scenarios such as e-commerce, takeaway, travel, and official account operations.

• This system architecture is a four-layer architecture implementation method of DDD domain-driven design. It introduces and shows readers how to develop such code in a way that attaches importance to the implementation of code.
• In the Domain layer, the system process design is gradually disassembled, and the design and development are carried out according to the domain modules of the responsibility boundary, and finally the logic function is arranged in the application layer.
• This system will reflect a lot of design pattern ideas and the final implementation. Only by combining DDD and design patterns can we develop a code structure that is easier to extend and maintain.

7. SpringBoot Middleware Booklet

There are 19 chapters in the whole booklet, including the design and development of 16 middleware, and a total of 30 code bases including test cases are provided for readers to learn and use. The middleware scenarios implemented by the booklet cover seven aspects: technical framework, data services, data components, distributed technology, service governance, bytecode, and IDEA plug-ins, which run through the core content commonly used in the entire Internet system architecture. It is very worthwhile to understand, learn, practice and master.

• technical framework : including Spring, SpringBoot configuration loading, custom annotations, scanning registered beans, etc., as well as ORM framework design principles and implementation. This part of the technology is mainly to combine the developed middleware with the framework, to develop the corresponding components or package them as the ability learning of various SpringBoot Starters.
• service : Mysql, Redis, Elasticsearch are all data services, usually need to develop various components to encapsulate the use of data services, Mysql we know JDBC, Redis we know Jedis, but Elasticsearch has x-pack, do you? To understanding.
• data component : The development of this type of component is to simplify the use of data services, Mysql+JDBC+ORM, can be very convenient to use database services, so whether Elasticsearch can also do corresponding component development, so that its query can also be Like using MyBatis? The technical ability of the bifold page needs to be familiar with the implementation principles of ORM frameworks such as MyBatis, and at the same time need to understand the concept of JDBC.
• Distributed technology : RPC framework, registry, distributed tasks are all very important technologies in the existing Internet distributed architecture, and how to implement an RPC framework is also the key point for R&D personnel to master. Using the registry, how to issue distributed scheduling tasks, etc., the learning of these technologies can give you a deeper understanding of the use of existing frameworks.
• Service Governance : circuit breaker, downgrade, current limit, volume cut, black and white list, and non-intrusive extension enhancement of existing methods, etc., can all become service governance components. Originally, this kind of technology was related to business logic code in the early stage. The integrated ones were gradually dismantled and developed into corresponding components. So we can learn how to package and integrate such components.
• bytecode & plug-in : In the process of system application operation and maintenance on the Internet, you will definitely come into contact with various monitoring systems, and many monitoring systems are non-intrusive full-link monitoring, so how are these implemented? In fact, they are based on bytecode instrumentation, enhancement of system methods, collection of corresponding runtime information, and monitoring. To expand the development of JVMTI and IDEA plug-ins, it is for the sustainable delivery and launch of the entire R&D process to improve the quality of delivery and reduce human efficiency.

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These technical materials written by Brother Fu are all technical content that is personally verified, systematically sorted, and summarized step by step. Therefore, in the process of learning, you must study against the cases corresponding to the source code, so that you can gain more.

Finally, I would like to say : Ability is the greatest guarantee for you to move forward. Even if you are a conscientious worker, you must have the skills that can leave behind and the ability jump out, so that you can go through turbulence and turbulence time and time again with relative stability.

This article participated in the SegmentFault Sifu essay "How to "kill" the interviewer?", you are welcome to join.