Interview experience and question Bank for Java programmers

Recently planned to change the city, can't stand the fog haze of Beijing, so ready to flee. So has been in the interview, sorting out some of the recent interview problems, for your reference. It will include some small experience in the interview, if you are a bully, hoping to give guidance. I am not Daniel, if you are Daniel, you can also ignore it. My job interview is a Java backend development engineer.

First, resume

The content should be included in the curriculum vitae should be education, their technical stack, and then do some of their own projects. The resume does not need to be too long, two pages of paper. It should focus on some of the frameworks you have used, some of your own projects, and your own harvest, concise first. General interviewers will not have a lot of patience to see your project detailed description, so as concise and clear.

Second, resume delivery

There are several ways of delivery, I believe we all know. Generally in the programmer's vertical recruitment site can be, such as tenderness, Boss Direct, Hook and so on. Zhaopin what, not very suitable for our programmer, you understand. In addition, because I am not Daniel, so if there are headhunting, I try not to ignore, because there is a lesson of blood??。 So try to vote your resume more reliable, or internal push.

Third, interview

Because I am a cross-city, so I received the interview is usually telephone interview + video interview, if the chat is almost, there is also on-site interview, will not adhere to the form.

Generally speaking, the interview process is not much worse. First introduce yourself, focus on some of your own work experience, as well as some of their main responsibilities of the content. This piece can be prepared in advance, but it does not need to be specially prepared, do not act like an endorsement, but feel untrue.

3.1 Technical Interview

The general company will have two to the technical interview, the technical interview rounds may be more, but the content of each round is not very consistent, the following list some of their own problems encountered.

3.1.1 Java Basics

At this point, you will generally be asked some basic Java knowledge, such as

• What is the difference between synchronized static modifier classes and methods
• HashMap principle, underlying data structure, rehash process, pointer collision problem
• HashMap Thread-safety issues, why this thread-safety issue occurs
• CONCURRENTHASHMAP data structure, underlying principles, put and get are thread safe
• Some content of Java Io, including Nio,bio, etc.

3.1.2 Java Advanced Features

At this point the question usually contains the JVM, multithreading some of the content, this piece of advice to look at the source code, roughly the following:

• Java thread pool construction method, meaning of inside parameters, and principle
• Volatile and threadlocal solved what the problem
• The specific implementation of CAS in Java
• The composition of the Java Virtual machine, and the life cycle of a Java object, as well as the contents stored in the stack and the method area
• The GC process for the JVM, including some practical analysis of the problem, such as explaining a phenomenon that allows you to analyze what might be causing the problem, how to tune the JVM parameters
• The difference between synchronized and lock, and the underlying implementation principle
• Conditions for full GC and minor GC triggering
• Selection of GC roots
• Jmap,jstat,jstack, such as the use of the scene, mat, etc.
• Loading process of ClassLoader
• Countdownlatch, Cyclicbarrier and semaphore, etc.
• New features in Java 8, etc.

3.1.3 Database

There are two kinds of databases, one is MySQL, the other is NoSQL database, including Redis, MongoDB and so on. General questions to ask are:

• Inner the difference between join and left JOIN, etc.
• SQL tuning, Explain,profile, etc.
• The difference between InnoDB and MyISAM
• ACID
• The transaction isolation level of the database, and what they can solve separately.
• Several data structures of Redis
• is Redis single-threaded or multithreaded
• The persistence of Redis
• The meaning of pessimistic lock and optimistic lock
• Leftmost prefix index, index data structure, clustered index, etc. (this block is not yet understood)

3.1.4 Frame 3.1.4.1 Spring

Because spring is our usual framework, the content of this piece will be asked more, and will be relatively thin.

• Two major features of spring (IOC and AOP)
• The life cycle of spring beans
• How spring solves the bean's circular reference problem
• The two implementations of AOP, and the difference between them (in fact, the use of dynamic agents, the specific dynamic agent is divided into two, one is the JDK dynamic agent, the main use of the JDK's reflection, there is a cglib, the difference can be their own search, the article more)
• AOP-General usage scenarios
• The transaction principle of spring

3.1.4.2 MyBatis

This piece of the question is relatively simple:

• The difference between $ and #
• The difference between MyBatis and hibernate
• The source code, generally asked relatively few

3.1.4.3 Dubbo

Because you usually use the Dubbo, so this piece will ask:

• The principle of RPC
• How Dubbo is done with remote calls
• How Dubbo is tuned
• Communication protocols for Dubbo
• Dubbo is how to achieve load balancing

3.1.4.4 ZooKeeper

• ZK's usage scenario
• The electoral mechanism of ZK
• The node type of ZK
• Consistent hash principle

3.1.5 Data Structures and algorithms

The content of this piece is the basis, if the interviewer doubts your ability, usually one will ask this part of the content, such as tree traversal, fast sorting and so on.

3.1.6 Linux

General will ask some of the use of the command, and then will give a real scene, let you use the command to troubleshoot the problem, the piece itself is not very familiar, need to strengthen as soon as possible.

3.1.7 Comprehensive Questions

The subject of this piece, the interviewer will generally ask more in-depth. For example, how to design a snapping system, string to Integer, and so on, this part of the test is a person's on-the-spot ability, and in peacetime work system design ability accumulation, and consider whether the problem is thoughtful and so on. There may be a detailed inquiry about the design of the system that you write on your resume, so when you write your resume, you must not write your own unfamiliar content, and you will not be able to speak clearly, so it is usually directly pass away.

Of course, you will also ask some commonly used MAVEN commands, design patterns of the topic (this part of the question is more than a singleton mode).

3.2 HR Interview

This piece of the general will ask some reasons for leaving, of course, will also ask some of the usual problems encountered in the work, how to solve their own. If you have a good chat, HR will talk to you about salary. When asked about the current salary, I am now telling the truth. Here, there may be a lot of people reported higher, almost, the problem is generally small, if too exaggerated, follow-up may have problems, such as to provide you with bank water, and so on, too much, there may be integrity issues.

In addition, the issue of salary increases, my principle is to consider the size of the company in advance, and then combined with the current salary, will generally set a range (later found that this is not good, will be passive), on the basis of the current salary 30% of the appearance (may be different around, but this will be more secure). If you are good at talking about this, please ignore it.

In addition, the most important may be five insurance one gold payment. Generally small companies will let you choose whether to avoid tax or not to avoid tax, which is still a bit of learning. Tax avoidance, you may have a very small provident fund. At present, I have met two kinds, one is a fixed amount per month to pay you a Provident fund, regardless of whether your future salary increases, are not related to the Provident Fund; There is also a quota for you to pay, generally is the salary of 7% to you, or according to the minimum standard to pay you. In this case, please consider carefully whether you need to receive an offer.

Finally, the benefits of this piece can also ask questions, such as asking some year-end awards, annual leave, overtime take some and so on.

Iv. final

Finally, I would like to say a few words.

The most important thing in an interview is honesty. I will not say will not, and then you can try to say some of their own ideas, if there is no idea, also say, nobody is perfect, can not be exhaustive, because you make up the words, and then in-depth to ask, you are out.

Make sure you get ready before the interview. For example, half a month or one months in advance, we should start to look at some basic content, to do a summary of the current work, find their own bright spot. The highlight is very important, the general interview, there are bright spots, the process of the interview you will be able to master a certain initiative.

Finally, when the new work is about to be settled, I wish you all the best job you can find.

Interview experience and question Bank for Java programmers