I felt that the interviewer was a project-oriented person, but the main focus was on the breadth of knowledge, not too difficult. I think it's a good idea to have a clear understanding of what you're writing in your CV and not to dig yourself a hole.

Candidates introduce themselves and the interviewer asks mainly for details of the project, including the background, functionality and which features the individual is responsible for implementing.

How is Redis used in the project? (Answer: Expiry mechanism for captcha at login, hotspot data caching.)

How do you ensure consistency between cached and database data in the project? (Answer: Update the database first, then delete the cache, but not discussed in detail.)

What are the basic data types of Redis?

Describe the commonly used collection containers in Java and their features or benefits? (Answer: HashMap was selected for discussion, and the underlying implementation principles of HashMap in JDK1.7 and 1.8 versions were discussed.)

What is the relationship between HashSet and HashMap?

Introduce the basic workflow of SpringMVC? (Answer: I misheard it at first and answered it as the flow from entering the URL in the browser to displaying the interface, then I answered it correctly after the interviewer reminded me.)

How many states are there in a thread? How many ways are there to create threads in Java?

Have you ever used Linux and what are the common commands used when deploying a project on a Linux server? (Answer: Full recitation of Linux commands that you know, not too familiar with this one.)

What difficulties did you encounter in the project? How did you solve them? (Answer: Discuss about ThreadLocal memory leak and how to solve it.)