This document has been online on Github for 6 days , and has gained a total of 55K+star Java interview magic skills ( I don’t need to say more about the number of praises, how high the quality is ). It is very comprehensive, including Java basics, Java collections, JavaWeb, Java exceptions, OOP, IO and NIO, reflection, annotation, multithreading, JVM, MySQL, MongoDB, Spring family bucket, computer network, distributed architecture, Redis, Linux, git, front end, algorithm and data structure, MyBatis, RocketMQ, Netty, Dubbo . The content is very rich, and has helped many people win offers from first-tier Internet companies.
Each knowledge point has a navigation bookmark page on the left, which is very convenient to read. Since there are many contents, let’s take a part of the picture here.
"Java Interview Skills" sorts out some Java interview questions that I have seen and experienced so far. The main sources of these interview questions are some websites and the content on github. Without further ado, just go to the picture above:
Linux topics
Microservice Topics
- What are the advantages of microservice architecture?
- What are the characteristics of microservices?
- What are the best practices for designing microservices?
- How does microservices architecture work?
- What are the pros and cons of microservice architecture?
- What is the difference between monolithic, SOA and microservices architecture?
- What challenges do you face when using microservices architecture?
- What are the main differences between SOA and Microservice Architecture?
- What is REST / RESTful and what is it used for?
- What are the different types of microservice testing?
Kafka topic
- What is Kafka
- consumer design
- How to get a list of topic topics
- What is the command line for producer and consumer?
- Why do we need a message system, can mysql not meet the demand?
- What is the role of Zookeeper for Kafka?
- There are three key differences between Kafka and traditional MQ messaging systems
- Talk about the three mechanisms of Kafka's ack
- What is Kafka's high availability mechanism?
- How does Kafka not consume duplicate data? For example, deductions, we cannot deduct repeatedly.
- In the case of kafka distributed (not stand-alone), how to ensure the sequential consumption of messages?
Elasticsearch Topics
- How much do you know about Elasticsearch, talk about your company's es cluster architecture, index data size, how many fragments, and some tuning methods.
- What is Elasticsearch's inverted index
- How Elasticsearch implements master election
- Describe in detail the process of Elasticsearch search?
- How does Elasticsearch realize the Master election?
- When the client connects to the cluster, how does it select a specific node to execute the request?
- In the case of concurrency, if Elasticsearch guarantees read and write consistency?
- How does Elasticsearch implement the aggregation of large data volumes (hundreds of millions)?
- Regarding GC, what are the things to watch out for when using Elasticsearch?
- How to monitor Elasticsearch cluster status?
Algorithms
- binary search
- Bubble Sort Algorithm
- insertion sort algorithm
- quick sort algorithm
- Hill sort algorithm
- Merge Sort Algorithm
- bucket sort algorithm
- Radix sorting algorithm
- pruning algorithm
- backtracking algorithm
- shortest path algorithm
- Minimum Spanning Tree Algorithm
- AES
- RSA
- CRC
- MD5
Data Structure Topics
- stack
- queue
- Linked list (Link)
- Hash Table
- sort binary tree
- prefix tree
- red black tree
- B-TREE
- bitmap
Zookeeper Topics
- What is Zookeeper?
- How does Zookeeper guarantee the distributed consistency characteristics?
- What does ZooKeeper provide?
- Know the ZAB protocol?
- How does zookeeper ensure the sequential consistency of transactions?
- How to deal with zk node downtime?
- The difference between zookeeper load balancing and nginx load balancing
- Why is there a Master in a distributed cluster?
- What are the deployment modes of Zookeeper?
- Does the cluster support adding machines dynamically?
- What is chubby, and what do you think compared with zookeeper?
- What are the Java clients of Zookeeper?
- The connection and difference between ZAB and Paxos algorithm?
MyBatis Topics
Dubbo Topics
- Is the service call blocking?
- What registry is generally used? Is there another option?
- Why does the service launch not affect the old version?
- How to solve the problem that the service call chain is too long?
- How many solutions are there for Dubbo cluster fault tolerance?
- Dubbo service is downgraded, how to retry on failure?
- Dubbo Monitor implementation principle?
- What design patterns does Dubbo use?
- Does Dubbo support distributed transactions?
- Tell me about the core configuration?
- What protocol does Dubbo recommend?
- What is the difference between Dubbo SPI and Java SPI?
- Why use Dubbo?
- What are the layers of Dubbo's overall architecture design?
- What communication framework is used by default, and are there any alternatives?
RabbitMQ Topic
Spring Topics
Spring Cloud Topics
Spring Boot Topics
MongoDB Topics
- What is mongodb?
- What are the characteristics of mongodb?
- What are the types of NoSQL databases?
- What is the most basic difference between MySQL and MongoDB?
- What makes MongoDB the best NoSQL database?
- How do you compare MongoDB, CouchDB and CouchBase?
- What is the role of analyzers in MongoDB?
- How to perform transactions/locks?
- Does MongoDB support stored procedures? If supported, how to use it?
Memcached topic
- What is Memcached and what does it do?
- What is the biggest advantage of Memcached?
- What are the application scenarios of the Memcached service in the enterprise cluster architecture?
- How to realize Memcached service distributed cluster?
- What are the characteristics and working principle of Memcached service?
- Briefly describe the principle of Memcached memory management mechanism?
- How does Memcached work?
- How does Memcached implement redundancy mechanism?
- How does Memcached handle fault tolerance?
- What is Memcached's multithreading? How to use them?
- How to implement session shared storage in the cluster?
- The difference between Memcached and Redis
Redis topic
- What is Redis?
- What are the benefits of using Redis?
- What are the advantages of Redis over Memcached?
- Is Redis single-process and single-threaded?
- Redis persistence mechanism
- Cache avalanche, cache penetration, cache warm-up, cache update, cache downgrade, etc.
- Redis data types, and usage scenarios for each data type
- Redis expiration strategy and memory elimination mechanism
- Redis common performance problems and solutions?
- Why are Redis operations atomic, and how to ensure atomicity?
- What is the persistence mechanism of Redis? Pros and cons of each?
- Redis expired key deletion strategy?
- Redis recycling strategy (elimination strategy)?
- Do you understand the synchronization mechanism of Redis?
- Have you ever used a Redis cluster? What is the principle of the cluster?
MySQL topics
- What are the database engines
- What are the three normal forms of the database
- What are the common indexing principles
- What is inner join, left outer join, right outer join?
- What are the problems caused by concurrent transactions?
- What are the transaction isolation levels? What is the default isolation level of MySQL?
- How to optimize the large table?
- What kinds of locks are there in MySQL?
- What are the different tables in MySQL?
- Briefly describe the difference between MyISAM and InnoDB in the MySQL database
- What is the difference between primary key and candidate key?
- What is the column comparison operator?
- Does MySQL support transactions?
- The underlying implementation principle and optimization of the index
JVM Topics
- How to get the memory used by a Java program? % of heap used?
- Can you guarantee GC execution?
- Explain Java heap space and GC?
- What's the difference between JRE, JDK, JVM, and JIT?
- How to judge whether the JVM is 32-bit or 64-bit through a Java program?
- Will there be a memory leak in java, please describe briefly.
- What is the difference between heap and stack in Java?
- Describe the principle mechanism of JVM loading class files
- What is GC? Why is there a GC?
- Talk about the new generation, old generation, permanent generation,
- Have you understood JVM parental delegation?
- Will garbage collection occur in the permanent generation of the JVM?
- What is a Java virtual machine? Why is Java called a "platform-independent programming language"?
Java Concurrency Topics
- Briefly describe your understanding of the thread pool
- There are several ways to implement multithreading in Java
- How to stop a running thread
- What does the volatile keyword do? Can order be guaranteed?
- What is the difference between SynchronizedMap and ConcurrentHashMap?
- Tell me about your understanding of the synchronized keyword
- Tell me how you use the synchronized keyword, have you used it in the project? The three main ways to use the synchronized keyword
- What is thread safety? Is Vector a thread safe class?
- Talk about optimistic lock, pessimistic lock, spin lock
- The difference between deadlock and livelock, the difference between deadlock and starvation?
- Difference between thread and process?
- What is context switching in multithreading?
Java serialization + annotation topic
Java IO/NIO + Reflection Topics
- The difference between Java IO and NIO
- The difference between byte stream and character stream
- multiplexing
- signal driven
- asynchronous synchronous
- The role of reflection
- Where will the reflection mechanism be used?
- reflection implementation
- Java reflection class
Java Exception Handling Topics
Topics on Java collections/generics
- The difference between ArrayList and linkedList
- The difference between HashMap and HashTable
- What is the difference between Array and ArrayList?
- Talk about the difference between List, Set and Map
- What is a Set collection
- Vector (array implementation, thread synchronization)
- Talk about LinkList (linked list)
- HashMap (array + linked list + red-black tree)
- HashTable (thread safe)
- type wildcard?
- generic class
- What is TreeSet (binary tree)
The space is limited, and it is impossible to show one question and one answer (these questions have been collected in this 55K+ star Java interview skills), code friends who feel that there is a need, please help me to like it (it can help more Many people saw it!)
