preface
It is estimated that some students will have questions, why accurate to the day? Is this supposed to be a dick?
A: Just to prove our rigor.
Certainly some students will ridicule: is it really a small factory? Estimate is a title party again, brag force, *&￥%￥
A: It is really a small factory, in a traditional telecom company, mainly doing project outsourcing. And 844 days from the day I left. 921 days from the day I understand the salted fish the better he will be, and refusal to be the headline guy the better he will be
When a salty fish how good, how suddenly think impassability, want to turn over?
A:
Outsourcing also has strong, you are not so obvious food?
A: I didn’t even know what a member variable was, so I was never afraid of a dish.
It took so long (August 19) for me to write this article, and I haven’t produced any technical articles (hydrology) in the last six months. Is it a degenerate and a salty fish?
Answer: actually 19 years thought to write this article, hoped to be able to help those who like me once schoolmate (xianyu) people, thought is to find a free weekend at that time! Free weekend! Free weekend! I haven’t written it until May this year. Just now, the business called me for the demand (Saturday), which has been squeezed dry.
Is this tutorial suitable for everyone? Will it go astray?
Answer: this tutorial is only suitable for single dog cultivation, do not have a family secretly cultivation, otherwise all consequences (light is noisy, restless, heavy is separated…) I accept no responsibility
My bus is almost at the stop. Why don’t you start?
Answer: ok, let younger brother for big ye you fine detail way
The body of the
The first step of celestial Cultivation: Physical Cultivation (Novice stage)
First of all, I searched the Internet for a bunch of Basic Java interview questions and memorized them for days and nights without saying anything. This method seemed rough, but it was really tricky.
At that time, MY dishes were very real and I did not understand many basic concepts. The questions on the back allowed me to quickly master the core basic knowledge of Java.
Put now, for Java beginners, I still suggest that you can use this method, because the interview questions are basically more important content, but also play a certain screening role, avoid beginners aimless learning (mucking).
Some people may be ashamed to back on the topic, garbage only back on the topic, I will not back, I want to bare face, show their strength.
The result is a large probability of hanging, hanging, resume screening hanging, and then silently back, and then…
Personally, I think memorizing questions is quite normal. Most People’s Daily work is basically CRUD, and many interview knowledge points are not used in daily life. I am a QPS less than 10 system, you ask me high concurrency, fuse, degrade, second kill system design?
In Ali, when most people go out for an interview, I believe that if they don’t memorize the questions, they must prepare for a period of time. Ali Intranet also has a brother wrote an article “those years, in order to enter Ali recited interview questions,” so far has 487 likes, 1755 favorites.
After reciting the basic interview questions, it is estimated that some students have inflated, feel very able to play, go out for the interview, and then go out to the probability of being a crazy operation of the interviewer, finally received the sentence has heard countless times: today’s interview is here, if there is a result we will inform you again.
Summary: In this stage, I mainly do two things: 1) help myself to quickly grasp the core basic concepts of Java; 2) All the things to be systematically studied in the second stage should be generally understood here, at least the core concepts.
Generally spend about a month of time to learn, can learn the time on the bus, subway, lunch break, after work in the evening, weekend, paid pull 💩, can use the time to use up. Maybe some of you said you were spending the weekend with your girlfriend. Girlfriend? It doesn’t exist.
Step 2: Practice qi (Apprenticeship)
After we are familiar with the core basic concepts of Java, we will systematically learn some core knowledge points of Java in the second stage: Collection, IO, reflection, concurrency, locking, multi-threading, database principle, JVM foundation, common middleware (Dubbo, Kafka, Redis, Zookeeper) core principle and framework (Spring, Mybatis, SpringBoot, SpringCloud) core principle.
Learning methods I suggest to read the source code and reading the main, read the blog and watch video as a supplement. Some students may hear to see the source code meng.
Look at the source code is to eat a meal, several other ways is to eat others chew the meal, other people’s things we can not guarantee its quality, so or priority to eat a meal. In addition, look at the source code is a kind of exercise for their learning ability, at the beginning of the pain, but after finding out the routine, in fact, it is not so difficult, and will let yourself benefit for life.
Just start looking at the source code, I recommend ArrayList, ArrayList is more common and very simple, very suitable for beginners.
There are more than 1400 lines of source code for ArrayList in JDK1.8 (half of them are comments), but we don’t need to look at all of them. We just need to look at the most important ones: base properties, constructors, get, set, add, remove, expand, etc.
After you look at the ArrayList, move on to the wife class LinkedList, which is typically asked together in an interview. After looking at the source code of these two classes, and then combine the source code to see the questions that will be asked in the interview, this knowledge point is basically mastered almost.
After reading ArrayList, it is estimated that some students have inflated, the source code is nothing more than this, rubbish.
The source code of HashMap is not a bit more complex than ArrayList, plus the JDK that write the source code is not standard, looking at the head of pain.
Of course, the rice is sweet, but the difficulty will be relatively large, so we also want to eat some second-hand rice properly (soft rice, aunt, I don’t want to work hard).
If we want to eat second-hand rice, we should also have a choice, otherwise you may not eat rice, but swill. Among these, books are generally more secure, especially those with good reviews by Douban, which have been tested by many people. There are some adhere to the original quality of the public number/blog, such as the public number programmer Jiong Hui (old face a red).
Reading a book, I was the first to see is that I bought when in university, I mat under the pillow, accompany me countless nights of the Java programming ideas, but to be honest, my personal feeling is not very suitable for beginners to read this book, gave me help is not so big, so if time is not a lot, my side is not recommended to read this book, But it smells good for pillows. It’s thick.
Of the books I’ve read, the ones I personally recommend at this stage are: The Art of Java Concurrent Programming, Java Concurrent Programming in Action, Deep Understanding of the Java Virtual Machine (recently published in its third edition), and Redis Design and Implementation. At that time, I was still a small chicken, but I did not feel unable to read these books, so I think it is suitable to read at this stage.
Summary: This stage of learning is continuous, in this stage we mainly put some important knowledge points for systematic learning, consolidate their own foundation, improve their knowledge breadth.
Source code learning focuses on JDK source code (JDK 1.8), the rest is mainly to learn its core principles. If you don’t know the core principles of a certain knowledge point, you can refer to the interview questions, which usually ask about the core things.
If you are currently working for an outsourcing company or some traditional company, you may want to take a jump after completing this phase. From outsourcing directly jump ali is not without, but less. Therefore, we need to find a platform to use as a springboard, preferably a unicorn, which is to shout out that people at least know there is such a company.
Step 3: Foundation building (Entry stage)
In this stage, I will further improve my knowledge depth and project practice on the basis of the second stage. Say straightforward point is to enhance their own bright spot, so that they have installed force in the interview capital.
In this phase, we will pick one or two commonly used middleware or frameworks and dive into their source code. For example: Spring, Mybatis, SpringBoot, SpringCloud, RPC (Dubbo, gRpc, company developed), MQ (Kafka, RocketMQ, company developed), Redis, Zookeeper, JVM, database middleware (TDDL, MyCat) ), etc.
The JDK source code is fine if you look at it directly, but if you look at the middleware and framework source code directly, you will know what cruelty is. A more reasonable way to learn is to debug the source code repeatedly + take notes. I usually download the source code locally and then take notes directly on the source code.
In addition to the source code, another important part of this stage is to improve their project highlights. Most of you have probably been asked this question in your interview: What are your highlights from the project? At this moment, MY inner OS is: I have a project with less than 10 QPS, and there is a chicken bright spot.
If your project has high concurrency and large data volumes, it shouldn’t be difficult to find the bright spot. Otherwise, we can look for it in the following directions: 1) complex scene scheme design; 2) Design of system stability guarantee: current limiting, fusing, degradation, etc. (6-digit password protects 2-digit deposit); 3) Investigation and solution of online problems: deadlock, downtime, frequent Full GC, etc.
In addition to these, there are many others, as long as we are able to greet men and find our own project highlights when we meet with project problems, it is natural.
Summary: This stage mainly focuses on improving the depth of my knowledge and highlights in the project. Let oneself in the interview time, can have pretend force capital. But remember, loaded force to grasp the scale, do not overdo it, after all, we are here to beg just, not to install force.
conclusion
The road of cultivating immortals is very bitter, countless lonely nights, countless temptations (the city of washing feet across the road is my dream THAT I dare not crave). If you can do this, I’m sure most people can easily scrape a meal and it’s possible to be a copycat.
But it is really not easy to stick to it, Jiong Hui now recalled that countless lonely nights, canthus can not help but wet. Here’s a martial arts secret that might help you stick with your studies: How to create a learning habit that will hopefully help you succeed.
Some students may have doubts, xiuxian does not have ten layers, how can only three layers be introduced?
Answer: my younger brother is untalented and uneducated. I think I am in the fourth level of cultivation.
How do you know if you’re crazy?
A: If you think you have learned a lot in this process, but find that you do not know more things, you are probably on the right path to cultivate immortal. I wish you all a success as soon as possible.
Jiong Hui you have changed, you are no longer the quiet handsome man.
Answer: hear this sentence, Jiong Hui canthus again wet. Jiong Hui once inspirational want to do a backbone of the technology of the blogger, do not make fancy, but later accidental opportunity Jiong Hui looked back at his 1 years ago when the blog, the heart of OS is: this is what dog shit, smelly and long.
Therefore, the subsequent Jiong Hui in the creation, will try to avoid the entire source code analysis, as far as possible to more understandable (SAO Qi) text and pictures to present.
The harder you work, the luckier you get. The [praise] [forwarding] of the old tie people is the biggest motivation for The creation of Jiong Hui.
