This article covers the alibaba, tencent, beating bytes, jingdong, giant Java interview questions, such as huawei, no matter you are to interview companies or ordinary Internet companies, the interview questions must be helpful to you, after all, the development direction of giant must be industry benchmarking, with many companies of the interviewer will also research companies interview questions.

At the same time, this algorithm will interview must be asked, and the algorithm does not only depend on on the back of the paper is useful, it is need to mathematical logic thinking, therefore, small make up for you at the end of the article will be prepared for a very good algorithm learning handbook, the emphasis is on learning thinking methods, few words said, directly to interview questions, selection of companies.

Due to the length of the article, it is impossible to present all the interview questions in the form of words. This article has selected some interview questions for you

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Java based

1. What are the data types in JAVA, and how many bytes each takes up?

2. Can the String class be inherited?

3. If two objects have the same hashCode(), equals() must also be true, right?

4. Is String a basic data type?

5. What are the classes for manipulating strings in Java? What’s the difference between them?

6. How many IO streams are there in Java?

7. What is the difference between BIO, NIO and AIO?

Is HashMap thread safe? What are the maps used concurrently? What are their internal principles, such as storage methods, Hashcode, expansion, default capacity, etc.

9. How to reverse a string?

10. Must abstract classes have abstract methods?

11. What are the differences between ordinary classes and abstract classes?

12. Can abstract classes use final?

13. What is the difference between ArrayList and LinkedList?

14. Data structure of ConcurrentHashMap (required)

15. The Effect of Volatile (考试)

How an Atomic class is guaranteed to be Atomic

17. Why use thread pools (required)

Redis

Application scenarios of Redis
Data types supported by Redis
Data structure of zSET table
Redis data Expiration Strategy
Redis LRU expiration strategy concrete implementation
How to solve Redis cache avalanche, cache penetration problem
Redis persistence mechanism
Why is Redis single threaded?
What is cache penetration? How to solve it?
How many ways can Redis persist?
Why is Redis so fast? (study)
How does Redis implement distributed locks?
How does Redis optimize memory?
What are the Redis elimination strategies?
What are the common performance issues with Redis? How to solve it?
What should I pay attention to when using Redis?

ZooKeeper

The CAP theorem
ZAB agreement
Leader election algorithm and process
What is Zookeeper?
How many deployment modes are available for ZooKeeper?
How does ZooKeeper synchronize the status of the primary and secondary nodes?

Mysql

The basic elements of a transaction
Transaction Isolation Level (required)
How to solve the concurrency problem of transaction (dirty read, magic read)
MVCC Multiversion concurrency control
What are binlog,redolog,undolog and what do they do
InnoDB row/table lock
What is the difference between MyISam and InnoDB? When to select MyISam
Why choose B+ tree as index structure
What can be stored in the leaf node of an index B+ tree?
When the query does not go to the (expected) index
How to optimize SQL
How does Explain parse SQL
The order by the principle of

JVM

Runtime data region (Memory model) (Required)
Garbage Collection Mechanism (required)
Garbage Collection Algorithm (required)
Minor and Full GC trigger conditions
GC Stop the World (STW)
Characteristics and differences of each garbage collector
Parental delegation model
JDBC and parent-delegate model relationships
What does a complete GC flow in the JVM look like? How does an object progress to the past? What are some of the major JVM parameters that you know

Spring

Implementation of IOC/AOP in Spring
Implementation of dynamic Proxy
How Spring resolves cyclic dependencies (level 3 caching)
Spring’s post-processor
How to implement @Transactional in Spring
Spring’s transaction propagation level
The connection and difference between BeanFactory and ApplicationContext

other

How to implement current limiting in high concurrency system
Design of high concurrency SEC kill system
How to design load balancing

Operating System

The difference between processes and threads
Several ways to synchronize processes
How threads are synchronized
What is a buffer overflow? What is the harm and what are the causes
How many states are there in the process
What’s the difference between paging and segmentation

Multithreaded piece

What is thread safety
How does volatile work? Does it replace locking?
The difference between “sleep” and “wait”
The meaning of sleep (0)
The difference between Lock and Synchronized
What is the principle of synchronized and where it is commonly used (e.g. the difference between loading static and non-static methods)

supplement

There will also be some computer networks and the like. Like message queues, RPC frameworks are relatively rare. Computer networks are layered, TCP/UDP, three-way handshakes. Operating systems are processes and threads, the data structure of processes and how they communicate.

Data structure sorting algorithm is also more often test, test words will let you write a quick row. The rest of the algorithm is accumulated by LeetCode. In fact, the algorithm questions of the non-algorithm post exam are quite simple, many questions are completely to check whether your intelligence is normal, a little difficult questions involve some algorithm ideas according to the classification of LeetCode topic type, each question do one or two basic can completely cope with the interview.

Next, it’s time to share notes on data structures and algorithms with you!

Data structure and algorithm notes

Dynamic programming design

Data structure family

Algorithmic thinking series

High-frequency interview questions series

Computer technology

The last

Interview is the most direct and effective way to get a salary increase, immediately gold nine silver ten come, you do a good job interview to build a plane, work screw ready?

Master these knowledge points, the interview in the candidates and can dazzle many, hit 9999 points. Opportunities are reserved for those who are prepared. Only with sufficient preparation can you stand out among the candidates.

If you need the full interview notes, just support this article.