One side of the ant gold suit ：
Phone call from Hangzhou in the afternoon , Ask if you are free , I'm free , Although I feel a little nervous , A little confused .
The question of the interview ：
- HashMap and Hashtable The difference between
- Implement an algorithm to ensure the iteration order HashMap
- Let's talk about sorting algorithms , stability , Complexity
- say GC
- Guaranteed internship duration
- Occupation planning
As a whole , There are many basic problems on one side , So the bloggers basically answered , There are still some uses for it . So it's not bad after one side , And then the next afternoon we met again .
Two sides of ant gold suit
On the other hand, I was the most flustered interview , Because two sides are the most important , It's the biggest executive interview , So it's very critical , As a whole , The rhythm on both sides is very fast , It's totally different from one side , The interviewer would like me to finish the answer in a concise way , So the surface is not very good , At the end of that time, I thought GG 了 , Fortunately, I was lucky in the end , The interview questions are as follows ：
- Self introduction. .
- JVM How to load a class , What are the methods in the parental delegation model ？
- HashMap How to achieve it ？
- HashMap and Concurrent HashMap difference , Concurrent HashMap Is thread safe , Concurrent HashMap How to ensure Thread safety ？
- HashMap and HashTable difference ,HashTable Is thread safe ？
- There are several ways of interprocess communication ？
- JVM Which areas are divided into , What do you do in every district ？
- JVM how GC, The new generation , Old age , Lasting generation , What's in store ？
- GC In the algorithm of citation reachability analysis , Which objects can be used as GC Roots object ？
- Quick sort , The process , Complexity ？
- What is a binary balanced tree , How to insert nodes , Delete node , Say the key steps .
- TCP How to ensure reliable transmission ？ Three handshake process ？
- TCP and UDP difference ？
- Sliding window algorithm ？
- Linux How to schedule processes under ？
- Linux What are your common commands ？
- When will the operating system deadlock ？
- frequently-used hash What are the algorithms ？
- What is a consistent hash ？
- How to understand distributed locks ？
- What are the paradigms in the database ？
- The structure of the index in the database ？ When it's appropriate to index ？
- Java Medium NIO,BIO,AIO What are the differences ？
- What tools are used to debug programs ？JConsole, Have you used it ？
- Now? JVM A thread in is suspended , How to find out the reason with tools ？
- The relationship between thread synchronization and blocking ？ Must synchronization be blocked ？ Does blocking have to be synchronized ？
- What is the difference between synchronous and asynchronous ？
- Thread pool used ？
- How to create a singleton pattern ？ Said double check , He said it was not thread safe . How to efficiently create a thread safe singleton ？
- concurrent Under the bag , What have you used ？
- What are the common databases ？redis Have you used it ？
- understand hadoop Do you ？ say something hadoop What are the components of ？hdfs,hive,hbase,zookeeper. Under the said mapreduce Programming model .
- What open source protocols do you know ？
- What open source software do you know ？
- What books have you been reading recently ？
- Do you have any questions for me ？
- Know what design patterns ？ Tell me which design patterns have been used
- How to judge whether a single linked list has rings ？
- How the operating system performs paging scheduling ？
- What is an anonymous inner class ？ How to access variables defined outside of them ？
The interviewer on both sides asked me urgently , I'm quick to answer , So there are two questions that are not well answered , But the interviewer made me feel a sense of awe , Because he speaks faster , But they can all come to the point , The most important thing to say is very acceptable .
Two sides passed , I got three calls that night ( Ali's efficiency really amazes me )
Three sides of ant gold suit
The three sides are already cross interviews , Basically around my project , After my previous interviews , At this time, I have a high interview experience value , So I didn't panic at all when I was on three sides , The answer is very steady , Three questions are as follows ：
- Self introduction. , What projects have you done .
- java How to divide the area of the virtual machine , The kinetic energy of each zone , This piece is free to play .
- In the parental delegation model , From top to bottom , Which class loaders are , Which classes are loaded respectively ？
- Is it possible that parent class loaders and child class loaders , Load the same class ？ If you load the same class , Which class to use ？
- HashMap Structure ,get(),put() How is it realized ？HashMap What are the problems ？
- ConcurrentHashMap Of get(),put(), How to achieve it ？ConcurrentHashMap What are the problems ？ ConcurrentHashMap Is your lock a read lock or a write lock ？
- HashMap And HashTable The difference between
- sleep() and wait() The methods of which class , What's the difference? ？synchronized How does the underlying layer achieve ？ What's the difference between code blocks and methods ？
- What is a thread pool ？ If you design a thread pool of dynamic size , How to design , There should be some ways ？
- What is a deadlock ？JVM thread deadlock , How do you judge what it is because ？ If you use VisualVM,dump Thread information comes out , What information will there be ？ This one asks a lot … I was confused when I asked . Because I haven't actually operated = =
- see jvm There are piles in the virtual machine 、 Thread information , What commands have you used ？ I've only used the graphical interface VisualVM...
- What are the garbage collection algorithms ？CMS Do you know? ？ How it works ？
- What is a transaction in a database ？ The isolation level of the transaction ？ Four characteristics of transactions ？ What is dirty reading , Fantasy reading , It can't be read repeatedly ？
- What are the structures of database indexes ？ I said, B Trees and B+ Trees , He said there were only these two . I said full text inverted index . Then introduce B+ Tree structure .
- How to write paging query statement in database ？
- What is a consistent hash ？ What problem to solve ？
- Redis Storage structure of , Or how it works , And mysql The difference between ？ What are the data types ？
- Used in the project redis, Why choose redis, Know more about NoSQL Database ？ How to use... In your project redis Of ？key What is it? ,value What is it? ？
- The process of merging and sorting ？ Time complexity ？ Spatial complexity ？
- What sort do you usually use ？ Quick sort . Talk about the situations that apply , Which scenarios are not applicable .
- What do you do in the project ？ Because I use Solr, He asked me Solr How it works ？
The final summary
Get rid of the algorithm , I'm not afraid anymore , There are these that need to be shared in the article Binary tree 、 Linked list 、 character string 、 Stack and queue, etc
Finally, share one more The ultimate gift bag of hand tearing Architecture ( Learning notes )： Distributed + Microservices + Open source framework + performance optimization
This article has been CODING Open source project ：【 A big factory Java Analysis of interview questions + Core summary learning notes + The latest explanation video + Actual project source code 】 Included