On the day 25K joined Tencent, I cried

A sad experience ：

Let's talk about my personal situation first , Computer science ,17 Bachelor degree , As soon as I graduated, I entered “ Ali ”Java post ( Only when I went in did I know that I had received an Alibaba outsourcing project , But just graduated, who knows what outsourcing is not ).

What's more sad is ： Just started because there were some changes at home , No energy or money to bear the cost of unemployment , That means you can't lose your job , Can only carry the burden silently , It doesn't matter if you are tired or bitter , As a result, I stayed almost 3 Years of time . It is a pity ( Maybe it's lucky ) Because it was affected by the epidemic last year , The company began to lay off workers , Survival is at stake . I finally can't hold on this year , And I've long known that staying in outsourcing is not a long-term solution , I want to change jobs all the time in two years ; stay 20 year 11 In January, I aimed at the year after “ Kim San Yin four ”;

But man is not as good as heaven , I missed three gold and four silver , Don't laugh at me. , I met several companies I wanted to go to , Either on two or three sides , There are also some hanging on the telephone interview , It's really a shame , alas , In fact, in the final analysis, my technology is too rubbish , It's my favorite dish ;

After that, I became a homeless man , But I can't let myself fall like this , I think I should improve myself , Put one more , This time, , I must do my best !

reflection ：

Every day for the past two years is to do whatever the project needs , Day after day CRUD, Do some repetitive brick work . What we have done is just a nail in this company , Did not properly expand their own technology stack ; In addition, for some reasons, the recruitment threshold has been raised a lot , At that time, many telephone interviews didn't pass the first level .

But I really should know this sentence ：“ The best way to destroy a young man , Just keep him busy ”.

Give your colleagues a suggestion ： Work overtime ≠ Improve yourself , Improving yourself means the improvement of the system , Promotion of special knowledge points , Have time to organize yourself and connect the technology from points to lines , And then connect them into a plane , To adapt to the trend ; Be sure to have your own programming thinking , You may not be proficient, but you should be familiar with the whole system , Know your own shortcomings , And extend the technology stack through their own advantages , This is the secret of not being eliminated by the industry ;

Actually , A blessing in disguise , Behind bad luck comes good luck . Since God has given this opportunity to organize yourself, we must make good use of it ;

It's time to fight back

The next thing to do is ：

• Sort out the knowledge system
• Establish learning priorities
• Whether the algorithm is important
• Sort out the real interview questions
• A good resume

Here I share one for free GitHub Superscript star 120k Of 《Java Comprehensive analysis of core advanced knowledge 》 Let's see , Whether it's used to consolidate the foundation , You can collect one for technical improvement , Read and learn thoroughly , Interview big factory so easy.

Here are some screenshots , Free download method is attached at the end of the article .

( One ). Basics

1、Java Basic skill

• Java introduction ( Basic concepts and common sense )
• Java grammar
• Basic data type
• Method ( function )

2、Java object-oriented

• Classes and objects
• Three characteristics of object orientation
• Modifier
• Interfaces and abstract classes
• Other important knowledge points

3、Java The core technology

• aggregate
• abnormal
• Multithreading
• File with the I\O flow

( Two ). Concurrent

1、 Concurrent container

• JDK Summary of concurrent containers provided
• ConcurrentHashMap
• CopyOnWriteArrayList
• ConcurrentLinkedQueue
• BlockingQueue
• ConcurrentSkipListMap

2、 Thread pool

• The benefits of using thread pools
• Executor frame
• ( important )ThreadPoolExecutor Class introduction
• ( important )ThreadPoolExecutor Examples of use
• Several common thread pools are explained in detail
• ScheduledThreadPoolExecutor Detailed explanation
• Thread pool size determination

3、 Optimistic lock and pessimistic lock

• What is pessimistic lock and optimistic lock
• There are two common ways to implement optimistic locks
• Disadvantages of optimistic lock
• CAS And synchronized The use of

( 3、 ... and ). JVM

1、Java Memory area

• summary
• Run time data area
• HotSpot Exploring virtual machine objects
• Key supplementary content

2、JVM Garbage collection

• uncover JVM The mystery of memory allocation and recovery
• The object has died ?
• Garbage collection algorithm
• Garbage collector

3、JDK Monitoring and troubleshooting tools

• JDK Command line tools
• JDK Visual analysis tools

（ Four ） The Internet 、linux、 Data structure and algorithm 、 database 、 The system design 、 Must know tool 、 Interview guide

Because the space is limited , Other contents will not be shown one by one , This advanced note has a total of 512 page . It should be very helpful for small partners who want to advance , I hope it can help you .

You can click on the business card below for free .