This document has gained 40K+star Java interview skills on Github (this is a good number, no need to say how high the quality is) 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-line Internet companies.
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"Java Interview Skills" compiled some of the Java interview questions I have seen and experienced in my career. The main sources of these interview questions are some websites and the content on github. Not much to say, just go to the picture:
Linux topic
Microservice topic
- What are the advantages of microservice architecture?
- What are the characteristics of microservices?
- What are the best practices for designing microservices?
- How does the microservice architecture work?
- What are the advantages and disadvantages of the microservice architecture?
- Monolithic, what is the difference between SOA and microservice architecture?
- What challenges do you face when using microservice architecture?
- What are the main differences between SOA and microservice architecture?
- What is REST / RESTful and what is its purpose?
- What are the different types of microservice testing?
Kafka topic
- What is Kafka
- Consumer design
- How to get a list of topics
- What are the command lines for producers and consumers?
- Why do I 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 the high availability mechanism of Kafka?
- How does Kafka not consume duplicate data? For example, deductions, we can't repeat deductions.
- In the case of Kafka distributed (not stand-alone), how to ensure the sequential consumption of messages?
Elasticsearch topics
- How much Elasticsearch knows, talk about your company's es cluster architecture, index data size, how many shards, and some tuning methods.
- What is Elasticsearch's inverted index
- How Elasticsearch implements master election
- Describe the process of Elasticsearch search in detail?
- How does Elasticsearch implement Master election?
- How does the client select a specific node to execute the request when connecting to the cluster?
- In the case of concurrency, what if Elasticsearch guarantees consistent reading and writing?
- How does Elasticsearch achieve the aggregation of large amounts of data (on the order of hundreds of millions)?
- Regarding GC, what should I pay attention to when using Elasticsearch?
- How to monitor Elasticsearch cluster status?
Algorithm topic
- Binary search
- Bubble sort algorithm
- Insertion sort algorithm
- Quick sort algorithm
- Hill sorting algorithm
- Merge sort algorithm
- Bucket sorting algorithm
- Base sorting algorithm
- Pruning algorithm
- Backtracking algorithm
- Shortest path algorithm
- Minimum spanning tree algorithm
- AES
- RSA
- CRC
- MD5
Data structure topic
- Stack
- Queue
- Link
- Hash Table
- Sorted binary tree
- Prefix tree
- Red black tree
- B-TREE
- bitmap
Zookeeper topic
- What is Zookeeper?
- How does Zookeeper ensure distributed consistency characteristics?
- What does ZooKeeper provide?
- Understand the ZAB agreement?
- How does zookeeper guarantee the order 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?
- How many deployment modes does Zookeeper have?
- Does the cluster support dynamically adding machines?
- What is chubby, and how do you compare to zookeeper?
- What are the java clients of Zookeeper?
- The connection and difference between ZAB and Paxos algorithm?
MyBatis topic
Dubbo topic
- Is the service call blocking?
- What registry is generally used? Are there other options?
- Why does the service launch not affect the old version?
- How to solve the problem of too long service call chain?
- How many solutions does Dubbo cluster fault tolerance have?
- Dubbo service is downgraded, what should I do if I fail to retry?
- How does Dubbo Monitor work?
- What design patterns does Dubbo use?
- Does Dubbo support distributed transactions?
- What are the core configurations?
- 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, are there other options?
RabbitMQ topic
Spring topic
SpringCloud topic
SpringBoot topic
MongoDB topic
- What is mongodb?
- What are the characteristics of mongodb?
- What types of NoSQL databases are there?
- 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 the analyzer in MongoDB?
- How to perform transaction/locking?
- Does MongoDB support stored procedures? If so, 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 Memcached service in enterprise cluster architecture?
- How to realize Memcached service distributed cluster?
- What are the features 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 the multithreading of Memcached? How to use them?
- How to realize session shared storage in 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 single-threaded?
- Redis persistence mechanism
- Cache avalanche, cache penetration, cache warm-up, cache update, cache degradation, etc.
- Redis data types and usage scenarios of each data type
- Redis's expiration strategy and memory elimination mechanism
- Common Redis performance problems and solutions?
- Why is Redis's operation atomic and how to ensure atomicity?
- What is the persistence mechanism of Redis? Their advantages and disadvantages?
- Redis expired key deletion strategy?
- Redis recycling strategy (elimination strategy)?
- Do you understand the synchronization mechanism of Redis?
- Have you used Redis cluster? What is the principle of cluster?
MySQL topic
- What are the database engines
- What are the three paradigms 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 large tables?
- What kind 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 the Java program? What percentage of the heap is used?
- Can you guarantee GC execution?
- Explain Java heap space and GC?
- What is 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 and mechanism of JVM loading class files
- What is GC? Why is there GC?
- Talk about the new generation, old generation, permanent generation of JVM,
- Have you learned about JVM parent delegation?
- Will garbage collection occur in the permanent generation of the JVM
- What is the Java virtual machine? Why is Java called a "platform-independent programming language"?
Java Concurrency Topics
- Briefly describe your understanding of thread pools
- There are several ways to achieve multithreading in Java
- How to stop a running thread
- The role of the volatile keyword? Can order be guaranteed?
- What is the difference between SynchronizedMap and ConcurrentHashMap?
- Talk about your understanding of the synchronized keyword
- Tell me how I use the synchronized keyword, have you used it in your 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?
- The difference between thread and process?
- What is context switching in multithreading?
Java serialization + annotation topic
Java IO/NIO + reflection topic
- The difference between Java IO and NIO
- The difference between byte stream and character stream
- Multiplexing
- Signal drive
- Asynchronous synchronization
- The role of reflection
- Where will the reflection mechanism be used?
- Reflection implementation
- Java reflection class
Java exception handling topics
Java collections/generic topics
- 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 set collection
- Vector (array implementation, thread synchronization)
- Talk about LinkList (linked list)
- HashMap (array + linked list + red-black tree)
- HashTable (thread safety)
- Type wildcard?
- Generic class
- What is TreeSet (binary tree)
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