The vigorous "Golden Three Silver Four" is imminent. In the past, some people were happy and some were worried about this epidemic. Whether you are happy or worried, learning is always good. No, the editor specially sorted out the spring recruitment interview knowledge points + answers (JAVA post), and share them together for everyone to see~
Note: Friends who need the full version of the knowledge points + answers can [see the picture below to add a small assistant] to receive it for free~
The first part Java related
1.1 JAVA basics
- The difference between object-oriented and process-oriented
- What are the characteristics of the Java language
- The most detailed and popular answers about JVM JDK and JRE
- Comparison of Oracle JDK and OpenJDK
- The difference between List and Set
- What is the main class of a Java program? What is the difference between the main class of an application and an applet?
- What are the differences between Java applications and applets
- The difference between character constants and string constants
- Three characteristics of Java object-oriented programming: encapsulation inheritance polymorphism
- Whether Constructor can be overridden
- Arrays.sort implementation principle and Collection implementation principle
- The difference between overloading and rewriting
- What is the difference between String StringBuffer and StringBuilder? Why is String immutable?
- Why is it illegal to call a non-static member in a static method?
- Define the role of a constructor that does nothing and has no parameters in Java
- What is the difference between import java and javax?
- What operator is used to create an object? What is the difference between an object entity and an object reference?
- The difference between HashMap 1.7 and 1.8, explain what optimizations have been made in 1.8 and how to optimize them?
- What is the difference between an interface and an abstract class?
- What are the differences between member variables and local variables?
- What is the role of a class's constructor? If a class does not declare a constructor, can the program be executed correctly? Why?
- What are the characteristics of the construction method?
- What is the difference between static methods and instance methods
- What is the difference between the equality of objects and the equality of references to them?
- Before calling the subclass construction method, the parent class construction method without parameters will be called first. What is the purpose?
- == and equals (important)
- hashCode and equals (important)
- Why is there only value passing in Java?
- Briefly describe the basic concepts of threads, programs, and processes. And what is the relationship between them?
- What are the basic states of threads?
- Exception handling in Java?
- Exception classification and handling mechanism
- final finally finalize
- Strong reference, soft reference, weak reference, phantom reference
- What if some fields do not want to be serialized in Java serialization?
- Two commonly used methods for obtaining keyboard input?
JAVA basics: the answer
JAVA basics: the answer
1.2 JAVA concurrency
JAVA concurrency: the answer
JAVA concurrency: the answer
The second part is Spring related
1.1 Spring
- What is the Spring framework? What are the main modules of the Spring framework?
- What are the benefits of using the Spring framework?
- What are the different types of events in the Spring framework?
- What design patterns are used in the Spring framework?
- What is Inversion of Control (IOC)?
- Please explain the IoC in the Spring framework?
- What is the difference between BeanFactory and ApplicationContext?
- How many ways to configure Spring?
- How to configure Spring based on XML configuration?
- How to configure Spring based on Java configuration?
- How to configure Spring with annotations?
- Please explain the life cycle of Spring Bean?
- What is the difference between the scope of Spring Bean?
- What are Spring inner beans?
- Are singleton beans in the Spring framework thread-safe?
- Please give an example of how to inject a Java Collection in Spring?
- How to inject a Java.util.Properties into Spring Bean?
- Please explain the automatic wiring of Spring Bean?
- Please explain the difference in auto-assembly mode?
- How to turn on annotation-based automatic assembly
- Please give an example to explain the @Required annotation?
- Please give an example to explain the @Autowired annotation?
- Please give an example of @Qualifier annotation?
- What is the difference between constructor injection and set value injection?
- What is the difference between FileSystemResource and ClassPathResource?
- BeanFactory 和 FactoryBean
- What is the understanding of Spring IOC and its initialization process?
- BeanFactory 和 ApplicationContext？
- How is the life cycle of Spring Bean managed? What is the loading process of Spring Bean?
- If you want you to implement Spring AOP, how do you do it?
- If you were to implement Spring IOC, what issues would you pay attention to?
- How does Spring manage transactions, transaction management mechanism?
- What are the different transaction propagation behaviors of Spring, and what are they used for?
- What design patterns are used in Spring?
- How does Spring MVC work?
- The principle of Spring cycle injection?
- How does Spring ensure the safety of Controller concurrency?
Spring: The answer
Spring: The answer
2.2 Spring Boot
Spring Boot: The answer
Spring Boot: The answer
2.3 Spring MVC
Spring MVC: The answer
Spring MVC: The answer
2.4 Spring Cloud
Spring Cloud: The answer
Spring Cloud: The answer
The third part of the database related
3.1 MySQL high-frequency interview knowledge points
- The four characteristics of transaction (ACID) atomicity, consistency, isolation, and durability?
- Concurrency of transactions? Transaction isolation level, what problems will each level cause, which level is MySQL by default?
- What is the difference between the three common MySQL storage engines (InnoDB, MyISAM, MEMORY)?
- MySQL's MyISAM and InnoDB storage engines, transaction and lock levels, and their respective applicable scenarios?
- The different elements of the query statement (where, jion, limit, group by, having, etc.) are executed in order?
- What is a temporary table, and when is the temporary table deleted?
- What is the difference between MySQL B+Tree index and Hash index?
- sql query statement to determine which type of index to create? How to optimize the query?
- What is the difference between a clustered index and a non-clustered index?
- What are the locks (optimistic locks, pessimistic locks), and how to add exclusive locks when selecting?
- What is the difference between a non-relational database and a relational database, and what are the advantages?
- Three paradigms of database, design data table according to a certain scene?
- 7 problems of database read-write separation, master-slave replication, master-slave replication analysis?
- Use explain to optimize sql and index?
- How to solve MySQL slow query?
- What are inner joins, outer joins, cross joins, Cartesian products, etc.?
- What kind of locks does mysql have, the principle of deadlock determination and specific scenarios, and how to solve the deadlock?
- What are the usage scenarios of varchar and char?
- mysql high concurrency environment solution?
- Transaction recovery mechanism (REDO log and UNDO log) when the database crashes?
MySQL high-frequency interview knowledge points: the answer
MySQL high-frequency interview knowledge points: the answer
3.2 MySQL performance tuning practice
MySQL performance tuning practice: the answer
Part IV Redis
- Data types supported by Redis
- What are the commonly used commands in Redis?
- What are the application scenarios of Redis
- What is a transaction
- Why redis transactions are not atomic
- What are the Redis transaction related commands?
- What is Redis persistence?
- What are the Redis persistence mechanisms?
- What is the difference between Redis persistence mechanism AOF and RDB?
- Advantages and disadvantages of RDB and AOF persistence mechanism
- What are the Redis elimination strategies?
- What are the Redis cache invalidation strategies?
- What is a cache avalanche? Is there any solution to prevent cache avalanches?
- What is cache warm-up? What is the solution?
- What is cache penetration? Is there any solution to prevent cache penetration?
- Cache degradation
- What is cache breakdown? What problems will it bring? How to solve?
- Two ways to achieve master-slave replication
- Do you understand the process of copying? Tell me about it
- The master-slave structure of redis
- What is Redis slow query? How to configure?
- What are the architectural patterns of Redis? Talk about their own characteristics
- Redis distributed lock
Redis: The answer
Redis: The answer
Part 5 Distributed Related
- Dubbo's underlying implementation principle and mechanism
- Describe the detailed process of a service from being published to being consumed
- How to do service governance in distributed systems
- The concept of interface idempotence
- How message middleware solves the problem of message loss
- How to deal with the failure of Dubbo service request
- Will the reconnection mechanism cause errors?
- Understanding of distributed transactions
- How to achieve load balancing, and what algorithms can be implemented?
- What is the purpose of Zookeeper and the principle of election?
- The vertical split of the data is split horizontally.
- Zookeeper principle and applicable scenarios
- zookeeper watch mechanism
- How to deal with redis/zk node downtime
- How to achieve a unique serial number in a distributed cluster
- How to make a distributed lock
- Which MQs have been used, how to use them, what are the advantages and disadvantages compared with other mqs, is the connection of MQ thread safe?
- How to ensure that the data of the MQ system is not lost
- List the database sub-database sub-table strategies you can think of; after sub-database sub-table, how to solve the problem of full table query
- Zookeeper's election strategy
Part VI JVM
- JVM memory structure
- Exploring HotSpot Virtual Machine Objects
- Garbage collection strategies and algorithms
- HotSpot garbage collector
- Memory allocation and recovery strategy
- JVM performance tuning
- Class file structure
- Timing of class loading
- The process of class loading
- Class loader
JVM: The answer
JVM: The answer
The seventh part of the algorithm
- Programming skills
- Linear table
- String
- Stack and queue
- tree
- Sort
- Find
- Brute force enumeration
- Breadth first search
- Depth-first search
- Divide and conquer
- Greedy Method
- Dynamic programming
- Figure
- Detailed implementation questions
Algorithm: the answer
Algorithm: the answer
At last
Please pay attention to all the friends who need the full version of the knowledge points + answers that need to be shared in the article: [See the picture below to add a small assistant] You can receive it for free! ! ! ! !
