Java interview
Everyone knows that Java interviews are getting harder and harder now! The main reasons are nothing more than two:
- With the rise of the Java industry, most of these people choose to learn Java , whether they are unemployed at home, dissatisfied with their current job, choose the wrong major in university, lack of money, or want to learn by themselves. ! The influx of a large number of talents has led to more and more job competition, and interviews have become more and more difficult!
- The other is the impact of the epidemic in the past two years. Many companies have declared bankruptcy and laid off employees. Coupled with the promotion of introversion in the Internet industry, it is already a very common phenomenon to screw screws during interviews for building rockets!
Recently, some fans and friends have been sending private messages to me saying that the Golden Nine and Silver October are coming soon, does LZ have a comprehensive interview question bank with high-frequency topics, and the interviews have been frequent recently, so I need to sort out systematically! Isn't this arranged for everyone today? I compiled this set of 1000+ Java interview manuals for a whole month, uploaded it to Git, and now the number of stars has reached 40K+
If you are still looking for interview questions everywhere! So! check it out! Suitable for reading crowd
- Beginner/intermediate/advanced Java programmers to be interviewed
- person who checks for gaps
- People who want to continuously improve and expand their Java technology stack
- Java interviewer
- JavaOOP/collection/generic/exception/lO and NIO/reflection/serialization/annotation interview questions
- What is OOP?
- What is the relationship between classes and objects?
- There are several naming conventions for data type identifiers in Java.
- The role of the instanceof keyword
- What is implicit conversion and what is explicit conversion
- Can Char type be converted to int type?
- Can it be converted into a string class Can it be converted into a double type
- What are the two types of exceptions in Java?
- What are the exception handling mechanisms?
- How to customize an exception
- try catch finally, there is return in try, is finally still executed?
- The difference between ArrayList and linkedList
- The difference between HashMap and HashTable
- Collection package structure, the difference from Collections
- Generic common features
- Talk about the difference between List, Set and Map
- What is the difference between Array and ArrayList?
- What are the characteristics of Map
- The collection class is stored in the Java.util package, and there are mainly several interfaces
- What is the list interface
- Talk about ArrayList (array)
- Vector (array implementation, thread synchronization) talk about LinkList (linked list)
- What Set collection
- The role of java reflection
- Where will the reflection mechanism be used?
- Implementation of reflection:
- A class that implements Java reflection:
- Advantages and disadvantages of the reflection mechanism:
- Java Reflection API
- Reflection usage steps (get Class object, call object method)
- There are several ways to get the Class object
- Dynamically create object instances using reflection
- What is java serialization and how to implement java serialization?
- Save (persist) the object and its state to memory or disk
- Serialized objects are persisted as byte arrays - static members are not
- Serialize user remote object transfer
- Serializable implements serialization
- writeObject and readObject custom serialization strategy
- Multithreading & Concurrency Interview Questions
- There are several ways to implement multithreading in Java to inherit the Thread class
- Implement the Runnable interface.
- ExecutorService.Callable, Future has return value thread
- Based on thread pool
- 4 thread pools
- How to stop a running thread
- What is the difference between notify0 and notifyAll0?
- What is the difference between sleep0 and wait()?
- 4 ways to terminate a thread
- The difference between start and run
- JAVA background thread
- What is an optimistic lock What is a pessimistic lock What is a spin lock
- Synchronized synchronization lock
- ReentrantLock
- Difference between Condition class and Object class lock method
- The difference between tryLock and lock and locklnterruptibly
- Semaphore semaphore
- The difference between Semaphore and ReentrantLock
- Reentrant lock (recursive lock)
- Fair locks and unfair locks
- synchronization lock deadlock
- Principle of thread pool
- thread complex
- Composition rejection policy for thread pools
- Java thread pool working process
- JAVA blocking queue principle
- Blocking Queues in Java
- JVM interview questions
- database interview
- Database storage engine lnnoDB (B+ tree)
- TokuDB (Fractal Tree - nodes with data)
- MylASM
- Memory
- What are the database engines
- The difference between lnnoDB and MylSAM
- index
- Common indexing principles are
- What are the three normal forms of the database
- What is Redis?
- How is Redis different from other key-value stores?
- Redis data type?
- What are the benefits of using Redis?
- What are the advantages of Redis over Memcached?
- What are the differences between Memcache and Redis?
- Is Redis single-process or single-threaded?
- What is the maximum capacity of a smart storage of type string?
- Redis persistence mechanism
- What is Memcached and what does it do?
- What application scenarios does the memcached service have 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?
- What is the biggest advantage of memcached?
- memcached and MySQL query
- Can the log feature be used for secure backups?
- Is null allowed?
- Update operations immediately fsync to disk?
- How to perform transactions/locks?
- Why is my data file so large?
- How long does it take to enable backup failback?
- What is master or primary?
- What is secondary or slave?
- Do I have to call getLastError to make sure the write took effect?
- Spring，SpringBoot，SpringCloud
- What configuration methods does spring provide?
- Does spring support centralized bean scope?
- What is the life cycle of the spring bean container?
- What is the inner bean of spring?
- What is spring assembly
- What are the methods of automatic assembly?
- What are the limitations of autowiring?
- What is annotation-based container configuration
- How to enable annotation assembly in spring?
- @Component Contoller, @Repository
- What is the use of @Required annotation?
- What is the use of @Autowired annotation?
- What is the use of @Qualifer annotation?
- What is Spring Boot?
- Why use Spring Boot?
- What are the advantages of Spring Boot?
- Which is the core annotation of Spring Boot? Which annotations does it mainly consist of?
- What are the ways to run Spring Boot
- How to understand Starters in Spring Boot?
- How to run some specific code when Spring Boo starts?
- Does Spring Boot need a separate container to run?
- What are monitors in Spring Boot? ;
- How to implement exception handling with Spring Boot?
- What is Spring Cloud?
- What are the advantages of using Spring Cloud?
- What does service registration and discovery mean? How does Spring Cloud implement it
- What does load balancing mean?
- What is Hystrix? How does it achieve fault tolerance?
- What is a Hystrix circuit breaker? Do we need it?
- What is Netflix Feign? What are its advantages?
- What is Spring Cloud Bus? Do we need it?
- What are microservices
- What is a service circuit breaker? What is a service degradation
- What is feigin? What are its advantages?
- What is the difference between Ribbon and Feign?
- What is Spring Cloud Bus?
- Springcloud circuit breaker role?
- Spring Cloud Gateway?
- As a service registry, what's so good about Eurekalk Zookeeper?
- What is Ribbon load balancing?
- What can Ribbon load balancing do?
- What is zuu|routing gateway
- What can the distributed configuration center do?
- MQ interview questions
- Dubbo interview questions
- MyBatis interview questions
- ZooKeeper interview questions
- What is Zookeeper?
- How does Zookeeper guarantee the distributed consistency characteristics?
- What does ZooKeeper provide?
- Zookeeper file system
- ZAB protocol?
- Four types of data node Znode
- Zookeeper Watcher Mechanism - Data Change Notification
- Client registers Watcher implementation
- Server-side processing Watcher implementation
- Client callback Watcher
- ACL permission control mechanism
- Chroot Features
- session management
- server role
- Server working status under Zookeeper
- data synchronization
- 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?
- How many machines are required for the cluster at least, and what are the cluster rules?
- Does the cluster support adding robots dynamically?
- Data Structures and Algorithms
- Elasticsearch interview questions
- Microservices Interview Questions
- What are the advantages of microservice architecture?
- What are the characteristics of microservices?
- What are the best practices for designing microservices?
- How does the microservices architecture work?
- What are the pros and cons of microservices 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 are the characteristics of microservices?
- What is Domain Driven Design?
- Why is Domain Driven Design (DDD) needed?
- What is ubiquitous language?
- What is cohesion?
- What is coupling?
- What is Ildempotence and where is it used?
- What is a bounded context?
- What is two-factor authentication?
- What are the credential types for factor authentication?
- What is a client certificate?
- What is the use of PACT in microservices architecture?
- What is OAuth?
- What is Conway's Law?
- What do you know about contract testing?
- What is End-to-End Microservice Testing?
- What is the purpose of Container in microservices?
- What is DRY in microservice architecture?
- What is the purpose of Docker?
- What is a canary release?
- What is Continuous Integration (CI)?
- What is Continuous Monitoring?
- What is the role of the architect in microservice architecture?
- Can we create state machines with microservices?
- What is Reactive Scaling in Microservices?
- Linux interview questions
at last
The length of the article is already very long, so I won’t show it too much. I hope that everyone who reads this article can seize the opportunity of Gold, September and Silver Ten, and get the Offer they want!