Preface
It is well known that the IT industry pays high salaries, so many people choose IT-related majors in universities. Even if people who are not majors, they want to go to a training institution and enter this industry after graduation.
But the saying that this industry will retire at the age of 35 has always been rumors.
In addition, in the past few years, major companies have continued to lay off employees. The most famous one is Huawei, and many people over 35 have been eliminated.
But these are all data magnified by the media, and the real situation is often not as cruel as it appears on the surface.
Many people who are capable in this area can frequently change jobs before the age of 30. After the age of 30, find a large company that is stable with them. The value you bring to the company is greater than the contribution the company gives you. Your position must be stable. Stable. And the upward trend is also good.
Generally, at the age of 35, they fainted from a technical management post. Whether in large companies such as NetEase, Alibaba, Huawei, Didi, Meituan, or some small Internet companies, these people are the backbone.
And let’s take a look at the people over 35 who were laid off. They have low positions, low incomes, and high substitutability. They have been mixed for more than 10 years. If you are still in the lowest-end position, you can only be eliminated by later young people. .
This is the reality in China. If you want to be a pure programmer, it seems very difficult. Unlike foreign countries, some people can still be a pure programmer at the bottom of their forties or 50s, focusing only on writing well. The code is good software.
But this is the reality. If you don't want to be retired at the age of 35, you should plan your career when you start.
Self-learning ability and problem-solving ability are always necessary abilities for IT professionals.
one side
1. Please program to realize the singleton mode, lazy and full of Chinese writing.
2. Please program to realize the producer-consumer model of Java.
3. The internal structure of HashMap? Internal principle?
4. Please briefly describe the Android event delivery mechanism. When is the ACTION_CANCEL event triggered?
5. The inter-process communication of Android and the inter-process communication of the Linx operating system.
6, JVM virtual machine memory structure, and their role.
This problem is also relatively basic. The memory structure of JVM is shown in the figure below.
7. Briefly describe the Android View drawing process and how the Android wrap_content is calculated.
8. There is an integer array containing positive and negative numbers, and then all the negative numbers in the array are required to be moved to the left of the positive number, and the relative position remains unchanged. The time complexity is O(n) and the space complexity is O (1). For example, {10, -2, 5, 8, -4, 2, -3, 7, 12, -88, -23, 35} changes to {-2, -4, -3, -88, -23 ,5, 8 ,10, 2, 7, 12, 35}.
Two sides
1. The data structure of the bundle, how to store it, since there is Intent.putExtra, why use the bundle.
2. Android's IPC communication method, have you used it
3. How does Android's multi-touch transfer core classes
4. The principle of asynctask AsyncTask is a combination package of Thread and Handler.
5. What are the android picture loading frameworks, and the differences under comparison
6. Some basic knowledge of picture frameworks
7. Other knowledge of modular development, hot update, and componentization of Android.
Three-sided, mainstream framework
- EventBus
(1) EventBus is obtained through annotation + reflection.
(2) Use ConcurrentHashMap to save the mapping relationship. The construction of the calling entity: Object in the calling entity, that is, the object that actually executes the method should not use strong references but Weak references should be used, because the static life cycle of the Map may be longer than the called object. If you use strong references, memory leaks will occur.
(3) The execution of the method uses the Dispatcher to dispatch the method, the asynchronous uses the thread pool to process, the synchronization is directly executed, and the UI thread uses the MainLooper to create a Handler, which is delivered to the main thread for execution.
2.
Dynamic agent in
Retrofit Java The role of dynamic agent Retrofit in
Retrofit
3.OkHttp
request task queue
reuse connection pool
Finally, I have compiled a lot of advanced PDF technical documents for Android. And some real interview questions analysis documents of big factories. Friends who need it can click GitHub to get it directly
The road of Android senior architect is very long, let's encourage together!
Image transfer in...(img-6eT7ZtEb-1611298400268)]
The road of Android senior architect is very long, let's encourage together!