Prepare for gold three silver four in advance! Attached my quick hand e-commerce department java back-end internship experience (oc)

Preface

Introduce my basic situation, non-undergraduate courses, master courses. Undergraduate with a double degree in computer science, and took four professional courses after entrance examination. The preparation time for the internship was to brush LeetCode from October 20, and probably more than 200 questions were brushed. The other eight-legged essay knowledge was prepared from half a month ago, because I had been busy setting up the topic before, and I didn’t start preparing until the end of December, which was very hurried. Resume No. 1.4 also voted for Kuaishou, Didi and NetEase. Kuaishou Efficiency soon got the offer and cancelled the Didi interview next week. I am more Buddhist, so I am going to practice in Kuaishou first. The project is a simple distributed project in the laboratory. Because there is no recording, I just talk about it from memory.

One side (1.7):

• For about an hour at one time, the interviewer is very good, listens carefully to what I say, and always affirms if I am right, and reminds me in many places. As a rookie who participated in the interview for the first time, I really thank the interviewer very much.
• I didn't introduce myself. I started to ask spring after seeing my project using springboot.
• What annotations have been used
• Wrote a few spring annotations and asked me what role
• The process of spring receiving front-end requests
• Do you know rpc? (Only know that it is a remote calling framework...)
• Do you know md5? (I only know that it is an encryption algorithm...)
• cookie和seession
• get and post
• The difference between threads and processes
• Let me talk about a few linux commands (ls, rm, mv, ps, etc.) and ask me if I know grep? (Keyword search)
• Redis asked me if I have used it. I said it was used in the project, but it was just the simplest use and the principle was never seen. (Only zookeeper and kafka were written on the resume, but neither of them was asked. Redis didn’t write it without preparation)
• How does redis set the value (set), what operation redis (jedis) used by java, and also asked some redis and other things, because I don't know anything about it.
• final, static keywords
• Some problems with the boxing and unboxing of java basic types and packaging classes (it seems to be wrong.)
• long has a few bytes
• Synchronized explain (I have finished the explanation and asked the interviewer if I need to talk about the bias locks? The interviewer said no, maybe they are not used to the stereotyped method)
• Handwritten two simple SQL statements (Later I found out that I also wrote one wrong...)
• Reverse the linked list from m to n node (a lot of algorithms are prepared, but the reversal of m to n has never been written. I think this is very simple. As a result, the first time I wrote the code on the spot, I was nervous to die, and the code was very messy after writing And there are bugs, the interviewer, Juhao, accompanied me to find the bugs, but later because of the messy writing, I didn’t find out, so I passed it)
• The longest non-repetitive substring (This question is the third question, so I wrote it one or two years ago, and I haven't touched it later. During the interview, I didn't expect to do it for a short time, so I said it would only be n2 violence. The interviewer reminded it and wrote it out...

Two sides (1.8):

• The second-side interviewer is more serious and ends in 30 minutes. .
• First introduce yourself, then ask questions about the project
• Spring receiving request processing
• The difference between get and post
• Ask me how to start spring on the server (make it into a jar package and run the jar command)
• How to run in the background (nohup & command)
• How to read the log when running in the background (>>Redirect to the file to see)
• What to do if the startup fails (maybe the port is occupied, use netstat to see who is occupied, either kill the occupied program or change the port of your own program)
• A scenario problem is probably that a user sends his userid to the backend every 10 seconds when shopping, and then let me implement an inshop method. This method passes in a userid to return whether the person is shopping. I use a hash table to save, and the user sends it once and saves it once. Inshop compares whether the date in the userid hash table and the current time are less than 10 seconds. Then I asked me the thread-safe version. I thought about it for a long time and didn’t figure out where the thread is unsafe, so I changed my head and changed it to concurrentHashMap. The interviewer felt unsatisfied. I forced to add synchronized to the two methods. Asked, I bit the bullet and said I was satisfied, and then I didn't ask. . .
• Maybe I feel that my scene is not well written, so let me write a binary tree non-recursive first-order traversal.
• A SQL that is more difficult than one side (still wrong, maybe it is written in my resume that I am familiar with MYSQL, but MYSQL I prepared more of eight-legged essays, and I practiced SQL statements for a day or two...)
• Then I wrote a select and asked me whether I can go index (do not go index, because there is a string conversion integer)
• What else does not take the index (only said that the principle of leftmost matching is not satisfied, and the other is not remembered)

hr surface (1.8):

• On the other side, I felt that I was not doing well, and thought it was cold, so I didn't dare to ask hr. About an hour later, I received the hr face notification, and the hr face was 6:30 that night. Mainly chat, ask about the internship time and so on. Then he said that he would go and pull through the technology and then reply to me.

Receive an offer (1.10)

Then sent me WeChat at noon today and said that the offer has been reviewed. In general, the question is relatively simple, because the project is indeed our laboratory, a lot of questions feel like I have participated in the project, and the deployment related questions are also more detailed. Many of the stereotypes prepared are useless. I have learned a lot about JVM, concurrency, and MYSQL. I am more Buddhist, and the review for the past half month has been quite torturous, so I canceled the interview for Didi next week, and I am ready to go quickly. Thank you for your help, Xiaocaiji hopes to be able to Help future classmates, and recruit character for yourself at the end of the fall.
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