HashMap+JVM+Index+Message Queue-NetEase carefully selects three aspects of Java development

There are benefits at the end of the article

NetEase carefully selects the java side

Basically only asked about Java related content

• Are there any difficulties encountered in the recent projects and how to solve them;

• HashMap introduces in detail, how to calculate the subscript value, what is the time complexity, what is the worst time complexity, and the time complexity is O(n) during expansion. What way do you have to optimize this time complexity? Degree?

• The underlying implementation principle of ConcurrentHashMap, how to find it, how to ensure thread safety when searching;

• Multithreading introduction, if a method is modified by synchronized, is there any way you can remove this keyword to ensure thread safety and improve efficiency;

• Thread pool introduces, what are the commonly used rejection strategies;

• How many threads are generally set in the thread pool, how do you set them, and why;

• What are the commonly used blocking queues in threads, which one do you generally use, the advantages and disadvantages of LinkedBlockingQueue and ArrayBlockingQueue;

• JVM CMS introduces what to mark when the CMS remarks, why it is so marked, what is the difference between marking garbage to be recycled and marking retained objects, which is better;

• If you encounter a problem in Java development (such as reporting an exception), how do you generally handle it;

For these issues, half an hour, because I was doing CV during graduate school, the projects were all CV-related, and I felt that there was no job-related project to be a weakness, so I hurried to find a project online. If you don't confirm what the interviewer thinks, give me a second chance, and I will come back to write the experience if there are two.

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Netease carefully selects the two sides of java

The interviewer is very cute. He first introduced himself and then introduced a project.

• Ask how redis is used in the project;

• If you implement the message queue yourself, what data structure is better and how to implement it;

• MySQL indexes, how to create indexes, and what are the good habits when creating indexes;

• The level of understanding of MySQL, what experience do you have when you usually use MySQL to write SQL statements, and how to build indexes for SQL range queries;

• Continue to talk about the project, because the project is CV related, so let me introduce deep learning and the models used;

• Which frameworks have been used normally;

The interview time is relatively short, basically just talking about the project, and then asking some basic questions about the database and Java, basically the above content. The questions are more divergent, and the interviewer will ask any interesting questions he thinks of. So don't talk about knowledge points that you are not sure about during the interview, or you may be caught by the interviewer.

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Netease carefully selects javaHR face

On-site interview at Hangzhou NetEase Building, 15 minutes. The interview is so fast, it is usually two extremes, either you have already planned to brush, or you have already planned to ask.

First of all, introduce some of the problems encountered in the project or internship, what are the challenges, how to solve them, and what are the gains;

In the project, what can be improved in the future, and how to improve;

What position do you want to work for in the future, and what are your plans ;

Future career planning;

There was only one round of hr interviews, and after the interview, I let go. Basically, they are asking questions about the project, not personal questions

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Java interview questions at the end of the article, advanced technical outline, structure data sharing

I sorted out all the topics of the three Ali interviews, and attached detailed answer analysis, generated a PDF document , which can be shared with interested friends for free

 

• The first thing to share with you is the algorithm and data structure

 

• The second is the high-frequency knowledge points and performance optimization of the database

 

• The third is concurrent programming (72 knowledge points to learn)

 

• The last one is the interview point + analysis + some of my learning books and materials for major JAVA architecture topics

 

There are more study notes for Redis, MySQL, JVM, Kafka, microservices, Spring family bucket, etc. I will not list them all here. If you need all of my review materials + study notes, you can