Write in front
It's the season of reaping offers again, are you ready? I used to sweep the offers from major factories. Again: cramming into giant is certainly not a given and should pay attention to sum up the usual accumulation, more thinking, more accumulation, and more sum up, several complex dish, the real work experience into their own work experience.
Face-to-face sharing
Today I will share with you a complete experience of interviews with major companies. Friends can compare them. Do you know all these interview questions? At the same time, I also compiled a set of interview analysis documents and structure study notes for these questions.
For those in need, add assistant vx: bjmsb2020 after one-click three-link article!
Technical round (90 minutes)
- The difference between hashmap and hashtable
- Why is there a deadlock
- jvm class loading
- Java reflection to get private attributes, change the value
- Reflective use
- Database used
- Project difficulties, problems
- How to solve the problems encountered in the project
- The most difficult place encountered in the project
Second round of technical side (120 minutes)
- Talk project
- Optimistic database lock usage
- How to sub-database and sub-table
- MySQL limit
- HashMap source code
- Design a thread-safe HashMap
- Realization of fast queue, time complexity and space complexity
- What algorithm
- How to turn the project into an SOA architecture
- Spring source code, the most profound module, aop use
- JVM memory model
- Garbage collection mechanism
- View garbage collection in the project
Three rounds of technical aspects (150 minutes)
- The underlying principle of ConcurrentHashMap?
- Handwriting an LRU (using LinkedHashMap)
- The underlying data structure of HashMap?
- Why does HashMap in JDK1.8 use red-black trees instead of ordinary AVL trees?
- Why does the linked list become a tree at 8?
- Why is the linked list returned from the tree at 6?
- The 7 parameters of the thread pool, how to configure the best?
- Talk about volatile
- How to realize the visibility of volatile and prohibit instruction reordering?
- What is CAS? What is the bottom layer of PriorityQueue, what is the initial capacity, and how to expand?
- If the original size is less than 64, the expansion will be 2 times +2, otherwise the expansion will be 1.5 times the original
- Why should the capacity of HashMap be set to a power of 2?
- Do you know how to skip the watch? What scenarios will be used?
- Does CopyOnWriteArrayList know that iterators support fail-fast?
- The underlying data structure of innodb?
- Why use B+ tree instead of B tree?
- Why use B+ tree instead of red-black tree?
- coding: How to find the k-th largest number in an unordered array, and write a binary tree level traversal
- If you don’t know the size of the data stream, take 100 of them. What kind of method can be the most random?
- Each item of n items has a certain value and is divided between two people. How to divide the value between two people is the smallest
Four-wheel technical side (120 minutes)
- Rights management in the project
- How to store login status
- The difference between session and cookie, how to manage session
- HashMap underlying structure
- Usage of synchronized keyword
- The lock difference between synchronized modified class method and ordinary method, can you still obtain object lock after obtaining class lock
- The role of the parent delegation model of the class loader, can you load a class repeatedly?
- The cache of the class of the class loader, what is the key
- Introducing Redis
- How to distribute data in different Redis
- Know the remainder algorithm?
- Spring's AOP implementation
- Bytecode structure
- Browser input URL process, combined with springmvc
Five rounds of technical (120 minutes)
- How to deal with a large number of hash collisions in HashMap
- Advantages of red-black trees over BST
- Why MySQL uses B+ tree
- Will there be multiple copies of data for multiple indexes?
- The isolation level of the database and the problem solved
- The default isolation level of the database will definitely produce phantom reading and how to solve it
- The entire process from entering the URL to the display, combined with springmvc
- Load balancing algorithm
- Huffman coding, how to solve the decoding problem
- How to check system load
- Describe a problem-solving process
- How to copy files from the server to the local, what command
Six rounds of technical aspects (90 minutes)
- Talk about the JVM garbage collection algorithm you know
- Which technologies are used in the project
- How to design the flow of the project, if it is you, how to design it
- The index structure used by MySQL, search efficiency
- MySQL query optimization
- MySQL slow query is turned on, sentence analysis
- HashMap search efficiency
- JVM memory model
- Use scenarios of design patterns and strategy patterns
- How to ensure single thread safety
- The default scope of Spring's beans
- Knowledge of Netty
- Future development plan
Seven rounds of HR noodles (40 minutes)
- Talk about the direction of development
- Talk about the problems caused by lack of experience
- What offer did you get and how did you think about it
Learn to share
To go to the interview after working for so long is definitely to take out my knowledge reserve again, to review all the knowledge points in place, you need to go through various methods and choose the one you are most used to. It is okay to read e-books or watch videos, but remember to make your own study notes, which can serve as a summary, and it will be particularly clear when you go to review.
Each knowledge point has a left-side navigation bookmark page, which is very convenient to read. Due to the large amount of content, here is a screenshot of some pictures. If you need it, remember to help like the comment and support it, and reply to the [interview] by private message to get the following 100% free Java interview analysis + technical knowledge notes" collection.
01 Java Quick Interview Guide
Concurrent programming
JVM
Spring
More not to show, and the interview analysis documents including Redis, RabbitMQ, distributed, microservices, Kafka, basics, netty, etc. are all sorted out!
02 Java from entry to architecture growth notes
Java from entry to architecture growth notes content
Novice Village-half a year from entry to development (beginning with 12K+)
- Java Fundamentals: Basic Syntax + Collection + Exception + Reflection + IO + TCP + Multithreading
- Java web articles: MySQL database + JDBC + Servlet
- Three framework articles: Spring+SpringMVC+MyBatis+Mall actual combat project
- SpringBoot+SpringCloud distributed development: introduction to microservices + actual combat
- Project experience: spike system design + SpringBoot mall actual combat
Java Basics
Three Frames
Project experience (spike + SpringBoot actual combat)
The first step of Daguai upgrade-development for 1 to 3 years
- Java Concurrent Programming Low Level : Concurrency Foundation + JMM + Thread Pool + Blocking Queue + Concurrent Collection + Concurrent Tool Class + Lock + Atomic
- JVM and performance tuning articles: memory area + garbage collector and memory allocation strategy + class loading mechanism + tuning
- Network programming: TCP/HTTP+Netty+ multiplexing
- SQL tuning articles: SQL optimization principles + lock + index + tuning + transaction + execution plan
- Tomcat bottom article: architecture + foundation + tuning + cluster + security
- Design Patterns: Six Principles + 23 Design Patterns
- Spring Source Code: Interpretation of IOC+AOP+ Declarative Transaction Source Code
- MyBatis source code article: MyBaits source code architecture analysis + MyBaits core module analysis + secondary cache
Concurrent programming
JVM and tuning articles
Network Programming
MySQL Tuning
Design patterns
Spring source code
MyBatis source code
The second step of Daguai upgrade: 4-5 years of senior high open
- Distributed thinking foundation: evolution process of large-scale Internet architecture + distributed knowledge that architects should have + detailed explanation of mainstream distributed architecture design
- Distributed monitoring: Zookeeper+Nginx
- Distributed message queue: RabbitMQ+RocketMQ+Kafka
- Distributed storage: Redis+MongDB+Mycat
Distributed monitoring
message queue
Distributed storage
The third step of Daguai upgrade: 5 to 7 years of advanced architecture
- Advanced microservice architecture: Docker+SpringCloud+Spring Cloud Alibaba+K8S
- 100 million-level traffic performance tuning combat: tuning basis + basic code performance optimization + design patterns and performance + concurrent programming performance optimization + JVM deep tuning + database performance tuning
- Practical combat in distributed scenarios of large-scale first-line factories : distributed transaction solutions + single-sign-on solutions for large-scale first-line factories + distributed task scheduling solutions + distributed lock solutions in high-concurrency scenarios + cache solutions
Performance tuning practical notes
Dachang Distributed Scenario Practical Notes
to sum up
The same is doing Java. Some people have no change in salary for 5 years, and some people have an annual salary of 30W after 2 years of work. This phenomenon may not have been obvious in the past few years , but with the rapid development of back-end technology in recent years, the era where only CRUD can travel the world is long gone, and the level of talent is becoming more and more differentiated. obvious.
Competition is always very cruel. After all, becoming an architect is not so easy. The growth of an architect comes from opportunity, hard work and talent! In this post-wave era, whether you are just working or have been developing for a few years, I believe that you need to read the above notes on Java from entry to architecture growth. I hope it will be helpful to your career development.
Friends in need, remember to help like and forward to support, add the assistant vx: bjmsb2020, you can get the following 100% free Java interview analysis + technical knowledge notes" collection!
