From 300 interviewers, I have summarized a set of Java interview documents you really need

I have been in contact with development for more than 8 years. From internship to team leadership, I have also summed up some of the experience!

If the things you share are valuable to readers and friends, there are dry goods! Can help! This is the purpose of my writing this article!

This article is a recommended article for documentation. At the end of the article, there will be ways to obtain it. If I write out my own experience completely, it is a difficult thing for me. The first is that there is not so much time, and the second is the article. The length of is too much! I have already started producing such a document in March, and I hope to take everyone from the perspective of interview questions to analyze and solve the problem!

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Not much nonsense, let's get started!

Java basics

1. The source code of HashMap, the principle of implementation, and what optimizations are made to HashMap in JDK8.
2. How does the expansion of HaspMap expand, and why are they all 2 to the power of N?
3. The difference between HashMap, HashTable, ConcurrentHashMap.
4. Under extremely high concurrency, which of HashTable and ConcurrentHashMap has better performance, why, and how to achieve it.
5. If HashMap does not deal with thread safety under high concurrency, what security risks will there be, and what are the specific manifestations.
6. The limited scope of the four modifiers in java.
7. Methods in the Object class.
8. The difference between interface and abstract class, pay attention to JDK8 interface can be realized.
9. The two ways of dynamic proxy, and the difference.
10. The way of Java serialization.
11. The difference between pass-by-value and pass-by-reference, what is Java like, and is there any pass-by-value reference?
12. One-ArrayList is deleted in the loop process, will there be a problem, and why.
13. The @transactional annotation will be invalid under what circumstances and why.

Analysis of Java basic interview questions:

JVM

1. Java class loading process?
2. Describe the principle mechanism of JVM loading Class files?
3. Java memory allocation
4. What is the structure of the Java heap? What is the permanent generation (Perm Gen space) in the heap?
5. What is GC? Why is there a GC?
6. Briefly describe the Java garbage collection mechanism.
7. How to judge whether an object is alive? (or how to judge GC objects)

JVM interview analysis document:

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java collection:

1. Tell me about the common collections, right?
2. The difference between HashMap and HashTable?
3. The specific process of the put method of HashMap?
4. How is the expansion operation of HashMap achieved?
5. How does HashMap resolve hash conflicts?
6. Why doesn't HashMap use hashCode directly (the processed hash value is directly used as the subscript of the table?

Java collection interview analysis:

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Microservice interview:

• What are the advantages of microservice architecture?
• What are the characteristics of microservices?
• What are the advantages and disadvantages of the microservice architecture?
• What is the difference between SOA and microservice architecture?

Microservice interview analysis:

Database interview questions

1. How to solve MySQL slow query?
2. What kind of locks does mysq have, the principle of deadlock determination and specific scenarios, and how to solve the deadlock?
3. What are the locks (optimistic locks, pessimistic locks), and how to add exclusive locks when selecting?
4. MySQL high concurrency environment solution?
5. Transaction recovery mechanism when the database crashes (REDO log and UNDO log)

Database topic analysis:

I have compiled these interview materials for more than half a year. My goal is to enable everyone to thoroughly understand the meaning of these interview questions and learn for the sake of learning!

If you want to obtain the above information, you can obtain it according to the following method. The space is limited. Java knowledge is definitely not a complete summary of an article. I hope that after receiving the documents, you will not be a collection party and use these documents. stand up!

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