The gold three silver four have passed, I will sort out a batch of high-frequency java interview questions for everyone, take a little patience to read them, the offer is soft!

Preface

The golden three and the silver four have passed. Many fans have sent private messages. I want me to help sort out the current popular technical points and interview questions. I got these interview questions from friends from many large companies. Basically, Ali, byte this time The big factory is just about these knowledge points, I hope you can take a bit of patience to read them, it will be very helpful to your interview!

Personally organize some information, friends in need can click to receive it directly.

Basic knowledge of Java

22 core Java architect books

Java learning routes and materials from 0 to 1

1000+ channels 2021 latest

database

· What are the principles for using mysq1 index?

· What data structure is indexed?

· What is the difference between B+tree and Btree?

· What storage engines does mysq have? What are the differences? To be detailed!!

How to design the database level of a high-concurrency system?

· What are the types of database locks? How to implement them?

· What are the database transactions?

Sub-database and sub-table

· How to design a sub-database and sub-table solution that can dynamically expand and shrink???

· Which sub-database and sub-table middleware have been used, and what are the advantages and disadvantages,

· Tell me about the underlying implementation principle of the sub-database and sub-table middleware that you know?

· I currently have a system that does not divide the database and the table. In the future, the system needs to be divided into the database and table.

· Let the system without sub-databases and tables dynamically switch to the system with sub-databases and tables???

· Do you know about distributed transactions? How did you solve it? TCC? What if there is a network problem and the network cannot be connected?

· Why do we need to sub-database and sub-table???

· What are the algorithms for distributed addressing? Do you know the consistent hash?

· Write the java implementation code by hand?? If you get the userId to get the slice, what should I do if I want to check the data in a continuous period of time?

· How to solve the primary key problem of sub-database and sub-table? What are the implementation solutions?

Distributed cache

· What is the difference between redis and memcheched? Why is single-threaded redis more efficient than multi-threaded memched?

What data types does redis have? In which scenarios are they used?

· How is the master-slave replication of reids realized? How is the cluster mode of redis realized? How is the key of redis addressed?

· How to design distributed locks using redis? Is it possible to use zk? How to achieve? Which of the two is more efficient?

· Do you know the persistence of redis? What are the disadvantages and advantages? What about the specific underlying implementation?

· What are the redis expiration strategies? LRU? Write the code for the java version?

Distributed Service Framework

· Tell me about the implementation process of dubbo? Can you continue to communicate after the registration center is hung up?

· Do you know the principle of zk? What can zk do? Do you know the Paxos algorithm? Tell me about the principle and implementation?

· Which serialization protocols does dubbo support? Hessian? Tell me about the data structure of Fhessian? Does PB know? Why PB is the most efficient?

· Do you know netty? What can netty do? What are NIO, BIO, and AIO? What is the difference?

· What are the dubbo replication balance strategy and high availability strategy? What about the dynamic proxy strategy?

· Why do we need to split the system? Is it possible to split without dubbo? What is the difference between dubbo and thrift?

Distributed message queue

· Why use message queues? What are the advantages and disadvantages of message queues?

· How to ensure the high availability of the message queue? How to ensure that messages are not repeatedly consumed?

What are the advantages and disadvantages of kafka, activemq, rabbitmq, and rocketmq???

· If you are asked to write a message queue, how do you design the architecture? Say-under your thoughts

Distributed search engine

· How is the working process of es realized? How to realize distributed

How can es improve query efficiency when the amount of data is large (billions of levels)?

· What is the working process of es query? Let me introduce the underlying lucence? Do you know the inverted index?

· What is the difference between es and mongdb? In what scenarios are they used?

· High concurrency and high availability architecture design

· How to design a high concurrency and high availability system?

· How to limit the current? How to do it in the project, talk about the specific implementation?

· How is the cache used? What are the consequences of improper use of the cache?

· How to fuse? What are the fuse frameworks? Do you know the specific implementation principle?

· How to downgrade? How to split the system, how to split the database????

JVM

· Please introduce the JVM memory model?? What garbage collectors have you used? Talk about it?

· How to deal with frequent online sending of ful1gc? What should I do if the CPU usage is too high?

· How to locate the problem? How to solve it? Talk about the solution ideas and methods.

· Do you know the bytecode? What are the bytecodes?

IntegerX5, inty=5, what steps do you go through when comparing x=y?

· Tell me about the class loading mechanism? What class loaders are there, and which files are loaded by these class loaders?

· Write the class loading Demo by hand

· Do you know osgi? How did he achieve it???

· What JVM optimizations have you done? What methods have you used? What results have you achieved???

· What is the difference between class.forName("java.langString") and String.class.getClassLoader().LoadClass("java.lang.String")??

Spring

· What are the mechanisms of spring? How is the bottom layer of AOP implemented? What about I0C?

· Does cglib know? What is the difference between it and jdk dynamic agent? Hand write a jdk dynamic agent?

letter of agreement

· Tell me about the four layers of TCP/IP?

· Http workflow??? What are the specific differences between http1.0http1.1http2.0?

· TCP three-way handshake, four-layer breakup workflow? Draw the flowchart? Why not four times, five times or two times?

· Draw the workflow of https? How to implement it? How to prevent packet capture?

algorithm

· It's relatively simple. I have a file with 4.5 billion Arabic numerals. How can I remove duplicates? How can I find the largest number?

data structure

Binary trees and red-black trees, etc.

The above are the interview questions that the host summarized and shared. The coverage of the topic is still quite wide, and we still need to prepare well. In addition to these technical questions, they are all routine questions that will be asked, such as why did they work well in the previous company or decided to change jobs, like stability or challenge, what is the expected salary, that's all .