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Summary of high-frequency test points for technical interviews-JAVA articles
Hello everyone, this is Xiaodai!
Today, let me introduce everyone's favorite Java article, Java stereotyped essay, but it is very, very, very large, but there are not so many questions in the interview, so I will introduce it today, the Java interview question with the highest frequency in the interview ~
This article is divided into four parts to introduce, namely Java foundation , JVM , concurrency and framework , classify Java stereotyped essays from four angles, and introduce them!
Some features of this summary are:
1) Close to the interview : almost 100% of the problems encountered in the interview;
2) Concise and practical : It will not cover all aspects, but will include the most important knowledge and the most frequently tested knowledge under each topic.
3) Do not give official standard answers : On the one hand, you can test your own mastery, and on the other hand, you can remember more deeply in actively searching for answers.
Past content of this series:
Summary of high-frequency test points for technical interviews-computer network articles: https://mp.weixin.qq.com/s/13oOfB0z4C1wQc301TcLdQ
Summary of high-frequency test points for technical interviews-MySQL articles: https://mp.weixin.qq.com/s/n_lK4P7jF35ow39e3XhHtQ
Summary of high-frequency test points for technical interviews - C++: https://mp.weixin.qq.com/s/VRFkrTImrcUo5rH1gIqLfA
Summary of high-frequency test sites for technical interviews - Redis: https://mp.weixin.qq.com/s/nHKv3ZMpAdoHyBABX1uKzQ
Summary of test points for HR face-to-face and rhetorical questions: https://mp.weixin.qq.com/s/_eFbmQgEGvGxM2LFHWUpSQ
Summary of high-frequency test points for technical interviews-Linux articles: https://mp.weixin.qq.com/s/lBA7hSdLnt3VEVO0evCBwA
Summary of high-frequency test points for technical interviews-operating system articles: https://mp.weixin.qq.com/s/u4vQGw9qK-do1D7qTaTOug
Summary of high-frequency test points for technical interviews - cloud native, microservice architecture, K8s, Docker, distributed articles: https://mp.weixin.qq.com/s/_fgkNf2bsFANXruPZjwyEg
Tips: Although this test site summary will not give the answer, but in the follow-up basic computer knowledge, it will give Linux, C++, JAVA, computer network, operating system, design pattern, data structure and algorithm, Redis, MySQL, A detailed version of stereotyped essay PDF on JS, CSS, VUE, HTML and other knowledge topics, including questions and detailed answers to questions, including answers to questions in this push series, and answers to questions that are also frequently tested. Among them, the back-end knowledge is sorted out by me, and the front-end knowledge is sorted out by a front-end boss ~ it is already being sorted out!
Let's start now~
1. Basics of Java
1) The difference between Java and C++
2) Features of the Java language
3) What are JDK, JRE, and JVM, and what are the differences?
The difference between JRE and JDK
4) Talk about the basic data types of Java
5) What is reflection, list the application scenarios of reflection, the advantages and disadvantages of reflection
6) What access modifiers does Java have, and what is their visible range?
7) Introduce automatic boxing and unboxing
8) Introduce, in inheritance, subclass and parent class, construction method, variable initialization, static variable initialization, common code block, execution order of static code block
Introduce the execution order of code blocks and constructors
9) Introduce the three major characteristics of object-oriented
10) What is compile-time polymorphism and runtime polymorphism
11) Introduce aspect-oriented programming (AOP)
12) The difference between overloading and rewriting
13) What members can be called by static methods, what members can be called by non-static methods, and why
14) The difference between object-oriented and process-oriented
15) The concept and difference between interface and abstract class
16) The difference between deep copy and shallow copy
17) The difference between equals() and ==
18) List the common methods of the Object class
19) The difference between String, StringBuffer and StringBuilder
20) Is String mutable or immutable, why is it designed like this
21) What are the Java exceptions?
22) Introduce meta-annotations
23) What is Generic Programming
24) Do you know about Java's IO flow, and which abstract class base classes are used?
25) What is the difference between BIO, NIO and AIO
26) Introduce ArrayList and LinkedList, what is the difference between the two
27) Tell me about the Set you know, what are the implementation methods, and what is the difference between them
28) What is HashMap, have you learned about it, how is the bottom layer implemented, how to add elements, obtain elements, expand capacity, and is it thread-safe?
29) Which data types in Java are thread-safe and which are not
30) How to ensure the thread safety of ArrayList
31) Introduce the new features of JDK8
2. JVM
1) What is the runtime data area
2) The difference between memory overflow and memory leak, when will memory overflow and memory leak occur
3) The reasons for stack overflow and heap overflow, please give an example
4) Talk about the composition of the JVM, and introduce the program counter
5) Introduce the runtime constant pool and string constant pool
6) What is direct memory
7) Introduce the process of creating objects
8) Introduce the memory layout of the object
9) How objects are accessed and located
10) How to judge whether an object is garbage
11) What garbage collection algorithms does the JVM have?
12) Introduce the garbage collector you know
13) Principles of memory allocation and recovery, tell me what you know
14) How to judge which objects have died
15) The process of class loading
16) What are the references in the JVM
17) What is the parent delegation model
18) How to judge whether two classes are equal
3. Concurrency
1) What are processes and threads, the difference between the two, context switching between processes and threads
2) The difference between concurrency and parallelism
3) The difference between synchronous and asynchronous
4) Advantages and disadvantages of multithreading
5) What is deadlock, the necessary conditions for deadlock, how to solve deadlock
6) The difference between sleep() and wait()
7) Do you know about volatile? Let me introduce it
8) Introduce the difference between synchronized and volatile
9) What is the difference between Lock and synchronized
10) What is a thread pool, its advantages and disadvantages, how to create a thread pool
11) What are the states of the thread life cycle
12) What methods do threads have
13) Ways of thread communication
14) What are the common parameters of the thread pool
15) What is AQS, what is its principle, and what is its function
16) Introduce ThreadLocal
17) What is CAS
18) Do you know the auxiliary classes commonly used by JUC? Let me introduce them
4. Framework
1) What is SSM
2) What is Spring, what modules are included, and what is the relationship between Spring, Spring MVC, and Spring Boot
3) What is Spring Ioc
4) Ioc container initialization process
5) What are the implementation methods of dependency injection
6) The process of dependency injection
7) What are the annotations for dependency injection
8) What is a Bean, the life cycle of a Bean
9) Introduce the scope of Bean
10) How to create beans through annotations
11) Talk about your understanding of AOP, what is AOP, and introduce the process of Spring AOP
12) What are the relevant annotations of AOP
13) Talk about Spring MVC, how MVC works
14) What are the core components of MVC
15) Talk about the design patterns used in the Spring framework, and talk about the advantages of these design patterns
16) The way Spring manages affairs
17) What are the isolation levels of Spring transactions?
18) What is Mybatis, why use Mybatis, advantages and disadvantages
19) Mybatis's first level cache and second level cache
V. Summary
Ok, so far, the introduction of the JAVA compulsory exam is over~
The original intention of this series is to give you the fastest way to get started with technical interviews . After going through the questions, you can kill the basic questions of technical interviews~
I hope it can help everyone~
Digression
Here is a little bit about what Xiaodai wants to update recently:
Mainly update two topics, plus organize some PDFs:
Required interview topics : Linux, HR, Operating System, Cloud Native & Distributed & Microservices, Scenario Questions & Intellectual Questions, Test Development, Front-end Development
State-owned enterprises in-depth secret topics : CCB Operation Data Center, Bank of Communications Headquarters Financial Technology Guan Peisheng, Aerospace Science and Industry Institute Third Department, Bank of Communications Headquarters Software Development, Industrial and Commercial Bank of China Software Center, Telecom Headquarters Cloud Network Operations Department, Bohai Bank Headquarters Information Technology Department, Tianyi Cloud, Information Technology Department of China CITIC Bank Headquarters, Guan Peisheng, Information Technology Department of Bank of China Headquarters
PDF arrangement : Xiaodai's 100 face-to-face interviews with autumn recruits, recommendations by state-owned and central enterprises in various regions, stereotyped essays for state-owned and central enterprises PDF
Regarding PDF, there are a lot of PDF materials that have been sorted out, and they are all available for free~
If you want to get information, you can add Xiaowo~!
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