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Fortunately, with this "Star" a Li Jing! "Poor country" guys have to be content with the status quo? (finally obtained the p7 post of Alibaba java development)

Preface

I believe that when you see this title, you can already associate with what kind of situation I am , Many people have heard such words in their lives, on the Internet and even at home ,“ You were born like this , It's good to live like this , Don't take risks for unrealistic dreams , It's very comfortable ”.

I know there's nothing wrong with this , There is no malice , Because it's also a choice, a life , It's just that I'm not reconciled to this . My friends hope to be patient and look down .

Self elaboration

Coordinates in a poor village in Shaoyang, Hunan Province , Chop wood 、 cattle 、 It's normal for us to do housework , It's also the right thing to do , Because I haven't been to big cities , Even towns are rare to see , And the people around you live like this . Until one day my parents took me to the place where they worked for a few days , It's the fuse that has an impact on me , This makes me really feel the gap between big cities and mountain villages .

Until I got to high school age , Although poor , But fortunately, my parents still attach great importance to my education , He sent me to boarding school in the town , I'm eager to learn myself , It's a win-win situation , I was admitted to a college in Hunan Province , I chose the major of software engineering , At this point, we began to embark on Java The road of no return .

follow-up

After graduation, I did back-end development in an ordinary Internet company , In fact, the job and salary at that time were very good for me , As the title says , My goal is more than that , I've always wanted to get into what's known as “ Chinese programmer technology ceiling ” Alibaba is engaged in Java Related positions .

My roommate advised me not to be so ambitious , Now the job is stable 、 Stable income is already very good , But I finally quit my job and went to Ali for an interview , But because of his poor skills, he was repeatedly hanged by the interviewer , There was a very bad time , I even doubt if I'm wrong , In the end, my parents gave me courage and encouragement ( Parents' love is selfless ).

Unwilling to be ordinary , Self-motivated forward

I gave myself two months , Crazy Technology , Of course, the process is very difficult , I also survived by my dreams and living up to my parents' expectations , Finally, Ali was captured Java Development p7 post , I have done a lot of interview preparation before the interview :

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(1)Java There must be a basic process for an interview

  • Self introduction.
  • Projects done

(2)Java Basics

  • Java Four basic characteristics , Understanding polymorphism and its application in projects
  • The difference between object-oriented and process oriented ? Is it possible to implement object orientation with process orientation ? Isn't that object-oriented ?
  • Overloading and rewriting , How to determine which function to call six basic principles of object-oriented development ( Single responsibility 、 Open the closed 、 Richter replacement 、 It's not easy to rely on - - Set up 、 Synthesis, aggregation and reuse 、 Interface isolation ), Dimitar's law . What principles have been used in the project
  • static and final Differences and uses of
  • Hash Map and Hash Table The difference between ,Hash Map Medium key Can it be any object or data type ? HashTable Is it thread safe ?
  • HashMap and Concurrent HashMap difference ,Concurrent HashMap Is thread safe ,ConcurrentHashMap How to ensure thread safety ?
  • Because others know how to implement the source code , Deliberately construct the same hash Attack on the string of , How to deal with ? that jdk7 What do I do ?
  • String.StringBuffer、StringBuilder And right String The understanding of invariance
  • String There's rewriting Object Of hashcode and toString Do you ? If rewritten equals Don't rewrite hashcode What will happen ?
  • Java serialize , How to achieve serialization and deserialization , What are the common serialization protocols
  • Java The way to realize multithreading and the difference between the three ways
  • Thread safety
  • How multithreads interact with information
  • What should be paid attention to when multithreads share a data variable ?
  • What is a thread pool ? If you design a thread pool of dynamic size , How to design , There should be some ways ?
  • Java Whether there are memory leaks and memory overflows concurrent Under the bag , What have you used ?
  • volatile How to ensure memory visibility of keywords sleep and wait They are methods of that class . What's the difference?
  • synchronized And lock The difference between , Use scenarios . seen synchronized Source code of ?
  • synchronized How does the underlying layer achieve ? What's the difference between code blocks and methods ?
  • There are two types of common anomalies (Exception,Error), Base classes for common exceptions and common exceptions
  • Java Medium NIO, Bl0, AI0 What are the differences ?
  • Design patterns learned , Considerations for singleton mode ,jdk Which source code uses your design pattern
  • What is an anonymous inner class ? How to access variables defined outside of them ? If you define a class , Including student ID , full name , fraction , How to make this right - Elephant as key? To rewrite equals and hashcode Do you
  • Why implement the memory model ?

(3) database

  • What are the common databases ?redis Have you used it ?
  • The advantages and disadvantages of database index and when the database index fails
  • Transaction isolation level
  • What are the paradigms in the database ?
  • The structure of the index in the database ? When it's appropriate to index ?
  • Redis Storage structure of , Or how it works , And mysql The difference between ? What are the data types ?
  • How to write paging query statement in database ?
  • database ACID
  • Dirty reading 、 No repeated reading or phantom reading
  • MyISAM and InnoDB The difference between engines

(4)JAVA virtual machine

  • JVM Garbage disposal method ( Mark clear 、 Copy 、 Tag to sort out )
  • JVM how GC, The new generation , Old age , Lasting generation , What's in store , And the role of each district ?
  • GC In the algorithm of citation reachability analysis , Which objects can be used as GC Roots object ?
  • When to proceed MinGC,FullGc
  • How each garbage collector works
  • Java The partition of virtual machine memory , The function of each area
  • What tools can be used to detect memory leaks
  • JVM How to load a class , What methods are there in the parental delegation model? Is it possible for parent class loaders and child class loaders , Load the same class ? If you load the same class , Which class to use ?
  • JVM thread deadlock , How do you judge what it is because ? If you use VisualvM,dump Thread information comes out , What information will there be
  • Java How to instantiate objects
  • What tools are used to debug programs ?JConsole, Have you used it ?
  • Read about JVM No tuning , What is the basic idea
  • Servlet Life cycle of
  • Jsp and Servlet The difference between
  • Save session state , What are the ways 、 What's the difference
  • cookie and session The difference between

(5)Spring&Hibernate

  • Spring iOC、AOP The understanding and implementation principle of
  • loc The loading process of the container
  • Dynamic proxy and cglib The difference of realization
  • The principle of proxy implementation
  • Hlbernate— The difference between L2 cache and L2 cache
  • Spring MVC Principle
  • sketch Hibernate Common optimization strategies .

(6) operating system

  • When will the operating system deadlock ?
  • How to understand distributed locks ?
  • There are several ways of interprocess communication ?
  • The relationship between thread synchronization and blocking ? Must synchronization be blocked ? Does blocking have to be synchronized ?
  • How the operating system performs paging scheduling ?

(7)Linux

  • Linux How to schedule the process ?
  • Linux What are your common commands ?

(8) other

  • frequently-used hash What are the algorithms ?
  • How to design a storage system for mass data
  • Implementation principle of cache , What should we pay attention to when designing cache
  • What is a consistent hash ? What problem to solve ?
  • Now a process is suspended , How to find out the reason with tools ?
  • What open source protocols do you know ?
  • What open source software do you know ?
  • computer network
  • Http and https The difference between
  • TCP How to ensure reliable transmission ? Three handshake process ?
  • Why? TCP Connection requires three handshakes , Not twice , Why?
  • What happens if the client keeps sending requests ?
  • ask : How do you know if the connection is malicious ? It could be a normal connection ?
  • GET and POST The difference between ?
  • TCP and UDP difference ? How to improve TCP
  • Sliding window algorithm ?
  • TCP Congestion handling - Conqestion Handlinq
  • The process from entering a web address to getting a page

(9) Algorithm

  • How to judge whether a single linked list has rings ?
  • Quick sort , The process , Complexity ? Under what circumstances , Under what circumstances does not apply ?
  • What is binary equilibrium I Trees , How to insert nodes , Delete node
  • The process of binary search
  • The process of merging and sorting ? Time complexity ? Spatial complexity ?
  • Here are 10000 numbers , How to find all the repeated numbers in it ? In every way you can think of , What's the time complexity and the space complexity
  • Give you an array , How to find and for K Two numbers of
  • 100000 Find the smallest or largest number of 10 individual ?

Except for the interview, of course , Solid technology is the foundation , During this period, I have also seen many in-depth Java Learning materials , It's also very helpful for the growth of my technology

Need to get “2020java Interview treasure +java In depth learning materials ” Just poke me Free collection !

A little advice for you

In fact, I have a few interviewer friends now , As far as I know, interviews are more and more comprehensive now , Technology is of course the top priority , But now enterprises also attach great importance to the comprehensive quality of employees , It will also be a bonus , I hope you can make a comment on yourself before the interview “ Leak filling ”;

ending

Some people like a comfortable life , And some people, like me, are not willing to achieve their goals , No matter what your choice is , Hope to be able to follow their own heart to fight .

No one wants a bad birth , But that's it , Don't just complain forever , It's completely possible to achieve what you deserve through your own struggle , see , Ali's offer I got it ! Don't envy , Ha ha ha !

Need to get “2020java Interview treasure +java In depth learning materials ” Just poke me Free collection !

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https://cdmana.com/2020/12/20201225150636097y.html

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