Social recruitment interview is indispensable -- 1000 interview questions for Android engineers from Internet companies

Domestic Internet interview , I'm afraid it's existing 、 The system closest to the imperial examination .
Take the United States for example , North American engineers pay more attention to Algorithms in the interview （Coding）, Will also join in recent years Design round （ System design and object-oriented design OOD） and BQ round （Behavioral question, Behavioral interview questions ）.

So why don't domestic interviews adopt such an investigation method ？ Simply speaking , Internet IT There are too many job seekers in the industry , If you are looking at a bunch of algorithm problems and design problems , Then the interviewer will be required to have a very high technical level , It also takes a lot of time, cost and energy .

therefore , Perhaps the current eight part essay interview is not the best solution , But it is also the most consistent with the current domestic IT Environmental practices .

If you want to stand out in such an interview, it is essential to brush questions . Today, Xiaobian will tell you that it was circulated in Ali some time ago 《1000 Dao Internet factory Android Engineer Interview Questions 》 Share it with you , Friends in need like + After attention ,【 Scan the qr code below 】 Access to information ~

Chapter one Java aspect

（ One ）Java Base part

• The difference between abstract class and interface ？
• Let's talk about final,static,synchronized What can keywords modify , And the effect of modification ？
• Please give us a brief introduction String、StringBuffer and StringBuilder The difference between ？
• “equals” And “==”、“hashCode” The differences and use scenarios ？
• Java The difference between deep copy and light copy ？
• Talk about Error and Exception The difference between ？
• What is the reflection mechanism ？ What are the application scenarios of reflection mechanism ？
• Talk about how to rewrite equals() Method ？ Why rewrite hashCode()？
• Java in IO There are several kinds of streams ?BIO,NIO,AIO What's the difference? ?
• Talk to you about Java Understanding of type erasure in generics , And talk about its limitations ？
• String Why is it designed to be immutable ？
• Tell me about your right Java The understanding of annotation ？
• To talk about Java Member variables , Creation and recycling of local and static variables ？
• Please talk about Java in String.length() How it works ？
• 

​

（ Two ）Java aggregate

• Talk about List,Set,Map The difference between ？
• Talk about ArrayList and LinkedList The difference between ？
• Please say HashMap And HashTable The difference between
• To talk about ArrayList Capacity expansion mechanism of ？
• HashMap Implementation principle of ？
• Please briefly LinkedHashMap How it works and how it is used ？
• Let's talk about it ConcurrentHashMap The understanding of the ?

（ 3、 ... and ）Java Multithreading

• Java What are the ways to use multithreading in ？
• Let's talk about several states of threads ？
• How to realize synchronization in multithreading ？
• Talk about thread deadlock , How to effectively avoid thread deadlock ？
• Talk about the causes of thread blocking ？
• Please talk Thread in run() And start() The difference between ？
• synchronized and volatile The difference between keywords ？
• How to ensure thread safety ？
• Talk about ThreadLocal Usage and principle ？
• Java In the thread notify and notifyAll What's the difference? ？
• What is a thread pool ？ How to create a thread pool ？
• To talk about java Several common locks of threads ？
• Talk about threads sleep() and wait() The difference between ？
• What is the pessimistic lock and the optimistic lock ？
• What is? BlockingQueue？ Please analyze its internal principle and talk about its use scenario ？
• To talk about java What are thread safe collections ？
• Java Why do you see Atomic class ？ Try to analyze its principle and disadvantages ？
• say something ThreadLocal Usage scenarios of ？ And Synchronized What are the characteristics of comparison ？

（ Four ）Java virtual machine

• To talk about JAVA Garbage collection mechanism ？
• Answer what is strong 、 soft 、 weak 、 Virtual references and the differences between them ？
• sketch JVM Loading mechanism and loading process of classes in ？
• JVM、Dalvik、ART The principle and difference of the three ？
• Please talk Java Memory recovery mechanism ？
• JMM What is it? ？ What problems does it have ？ How to solve ？
  

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Chapter two Android aspect

（ One ）Android The four components are related

• Activity And Fragment Several common ways of communication between ？
• LaunchMode Application scenarios of ？
• BroadcastReceiver And LocalBroadcastReceiver What's the difference? ？
• about Context, How much do you know ?
• IntentFilter What is it? ？ What are the usage scenarios ？
• To talk about startService and bindService The difference between , Life cycle and usage scenarios ？
• Service How to keep alive ？
• A brief introduction ContentProvider How to realize data sharing ？
• When switching between horizontal and vertical screens Activity Life cycle of ?
• Activity in onNewIntent Method invocation timing and usage scenario ？
• Intent Is there a limit on the size of the transmitted data ？ How to solve ？
• say something ContentProvider、ContentResolver、ContentObserver The relationship between ？
• say something Activity Loading process ？

（ Two ）Android Asynchronous task and message mechanism

• HandlerThread Usage scenarios and usage ？
• IntentService Application scenarios and use gestures ？
• AsyncTask Advantages and disadvantages of ？
• Talk to you about Activity.runOnUiThread The understanding of the ？
• Whether the child thread can update UI？ Why? ？
• Talk about Handler Mechanism and principle ？
• Why create in child thread Handler Would throw exceptions ？
• Try to analyze from the perspective of source code Handler Of post and sendMessage Differences of methods and application scenarios ？
• Handler There is Loop Dead cycle , Why not block the main thread , What is the principle ?
  

（ 3、 ... and ）Android UI Rendering correlation

• Android Make up the difference between animation and attribute animation ？
• Window and DecorView What is it? ?DecorView How to communicate with Window To make a connection ?
• Briefly Android in UI Refresh mechanism of ？
• LinearLayout, FrameLayout, RelativeLayout Which is more efficient , Why? ？
• Talk about Android Event distribution mechanism of ？
• Talk about customization View The process of ？
• in the light of RecyclerView What optimizations have you made ？
• Talk about how to optimize ListView？
• Talk about customization LayoutManager The process of ？
• What is? RemoteViews？ What are the use scenarios ？
• Talk about getting View Several methods of width and height ？
• Talk about interpolator and estimator ？
• getDimension、getDimensionPixelOffset and getDimensionPixelSize Differences among the three ？
• Please talk about... In the source code StaticLayout Usage and application scenarios ？
• used ConstraintLayout Do you ？ What are its characteristics ？
• About LayoutInflater, How it passes inflate Method to get the specific View Of ？
• To talk about Fragment Lazy loading ？
• Talk about RecyclerView Cache mechanism ？
• Please talk View.inflate and LayoutInflater.inflate The difference between ？
• Please talk invalidate() and postInvalidate() Differences of methods and application scenarios ？
• Talk about customization View And customization ViewGroup？
• To talk about SurfaceView And TextureView Usage scenarios and usage ？
• To talk about RecyclerView.Adapter How are the refresh methods different ？
• Talk to you about Window and WindowManager The understanding of the ？
• To talk about Activity,View,Window The relationship among the three ？
• I know WindowInsets Do you ？ What applications does it have ？
• Android in View Differences between several common displacement modes ？
• Why? ViewPager nesting ViewPager, Inside ViewPager Scrolling is not blocked ？
• Please talk Fragment Life cycle of ？
• Please talk about what is synchronization barrier ？
• To talk about ViewDragHelper How it works ？
• Talk about the screen refresh mechanism ？

（ Four ）Android Performance tuning related

• Talk to you about Android Understanding of performance optimization ？
• Under what circumstances can memory leakage be caused ？
• Customize Handler How to effectively avoid memory leakage when ？
• What circumstances can lead to oom problem ？
• ANR Scenarios and solutions ？
• Talk about Android Memory optimization in ？
• Talk about the skills of layout optimization ？
• Android Picture optimization scheme in ？
• Android Native Crash How to analyze and locate the problem ？
• Talk about how to give apk Slimming ？
• Talk about how you optimize App Of the startup process ？
• Talk about the steps of code obfuscation ？
• Talk about how to WebView To optimize ？
• How to handle the loading of large drawings ？
• Talk about how to optimize network requests ？
• Please talk about how to load Bitmap And prevent memory overflow ？
  ​ Bold style

（ 5、 ... and ）Android Medium IPC

• Please answer Android Communication between processes ？
• Please tell me about you Binder The understanding of mechanism ？
• Talk about AIDL？

（ 6、 ... and ）Android System SDK relevant

• Please talk briefly about Android The architecture of the system ？
• SharedPreferences Is it thread safe ？ its commit and apply What's the difference ？
• Serializable and Parcelable The difference between ?
• Please give us a brief introduction Android 7.0 New features ？
• Talk about ArrayMap and HashMap The difference between ？
• In a nutshell LruCache Principle ？
• Why recommend SparseArray Instead of HashMap？
• PathClassLoader and DexClassLoader What's the difference ？
• say something HttpClient And HttpUrlConnection The difference between ？ And talk about why the former was replaced ？
• What is? Lifecycle？ Please analyze its internal principle and usage scenario ？
• To talk about Android Signature mechanism of ？
• Talk about Android apk Build process ？
• Briefly Android 8.0、9.0 What new features have been added ？
• Talk about Android10 What has been updated ? How to adapt ?
• Please briefly Apk Installation process ？
• Java And JS How code is muted ？ Have you done relevant optimization ？
• What is? JNI？ Let's talk about how to realize Java And C++ Intermodulation of ？
• Please briefly start by clicking the icon app Startup process ？
  （ 7、 ... and ） Third party framework analysis
• To talk about LeakCanray How it works ？
• To talk about EventBus Principle ？
• Talk about interceptors in network requests （Interceptor）？
• To talk about Glide Cache mechanism ？
• ViewModel What problems do you want to solve ？ And briefly talk about its internal principle ？
• Please talk about the dependency injection framework ButterKnife Implementation principle of ？
• To talk about RxJava Back pressure principle ？
  

（ 8、 ... and ） Integrated technology

• Please tell me about you MVC and MVP The understanding of the ？
• Introduce what you know Android Several storage methods ？
• Briefly describe the principle of thermal repair ？
• Talk about how to adapt to more models ？
• Please talk about how you carry out multi-channel packaging ？
• MVP How do you deal with Presenter Layer to prevent memory leakage ？
• How to calculate the memory space occupied by a picture ？
• Have you met 64k problem , How to solve ？
• How to optimize Gradle The speed of building ？
• How to get Android Unique equipment ID？
• To talk about Android P Ban http What's the impact on our development ？
• What is? AOP？ stay Android What application scenarios does it have in ？
• What is? MVVM？ How do you apply it to specific projects ？ – Please talk about how you realize data embedding ？
• If you realize the breakpoint upload function , What do you think should be done ？
• webp and svg What are the characteristics of the pictures in different formats ？ How to be in Android Use in ？
• Tell me how you do unit testing ？ And how to apply it to MVP and MVVM in ？
• about GIF What are the ideas and suggestions for image loading ？
• Why migrate the project to AndroidX？ How to migrate ？

（ Nine ） Data structure

• What is bubble sorting ？ How to optimize ？
• Please use Java Implement a simple single linked list ？
• How to reverse a single linked list ？
• Talk about your understanding of time complexity and space complexity ？
• Talk about how to judge a linked list into a ring ？
• What is a red-black tree ？ Why red black trees ？
• What is a quick sort ？ How to optimize ？
• Talk about circular queues ？
• How to judge the cross of single linked list
  ​

（ Ten ） Design patterns

• Please briefly talk about singleton mode ？
• How much do you know about the six basic principles of object orientation ？
• Please list several common factory patterns and explain their usage ？
• Talk about the design patterns and usage scenarios used in the project ？
• What is agent mode ？ How to use ？Android Proxy mode in the source code ？
• Let's talk about singleton mode , Builder pattern , Usage scenario of factory mode ？ How to choose ？
• Talk about your understanding of prototype patterns ？
• Please talk about the principle of strategy mode and its application scenario ？
• The difference between static agent and dynamic agent , What scenarios to use ？
• Let's talk about the usage scenario of the responsibility chain model ？

（ 11、 ... and ） Computer network

• Please briefly Http And Https The difference between ？
• say https,udp,socket difference ？
• Please briefly describe http Process of network request ？
• To talk about TCP/IP Three handshakes , Four waves ？
• Why do you say Http It is a reliable data transmission protocol ？
• TCP/IP What are the layers of the agreement ？TCP and HTTP Which floor do they belong to ？

（ Twelve ）Kotlin aspect

• Please briefly describe what is Kotlin？ What are its characteristics ？
• Kotlin Notes in @JvmOverloads The role of ？
• Kotlin in List And MutableList The difference between ？
• Kotlin Several common ways to implement singleton in ？
• Talk to you about Kotlin Medium data Keyword understanding ？ What are the characteristics compared with ordinary classes ？
• What are delegate properties ？ Please briefly talk about its usage scenario and principle ？
• Please give an example of Kotlin in with And apply Application scenarios and differences of functions ？
• Kotlin in Unit The role of type and its relationship with Java in Void The difference between ？
• Kotlin in infix The principle and usage scenario of keywords ？
• Kotlin What are the visibility modifiers in ？ Compared with Java What's the difference? ？
• You feel Kotlin And Java What problems should be paid attention to in hybrid development ？
• stay Kotlin in , What is deconstruction ？ How to use ？
• stay Kotlin in , What is an inline function ？ What's the role ？
• Talk about kotlin Construction method in ？ What are the precautions ？
• Talk about Kotlin Medium Sequence, Why does it handle collection operations more efficiently ？
• Please talk Kotlin Medium Coroutines, What's the difference between it and thread ？ What are the advantages ？
• Kotlin How to safely handle nullable types ？
• say something Kotlin Medium Any And Java Medium Object What are the similarities and differences? ？
• Kotlin Does the data type in have implicit conversion ？ Why? ？
• Kotlin There are several ways to traverse the collection in ？
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PS: We should remember that the purpose of the interview questions is not to let everyone recite the questions , But to help you review from different dimensions , Learn from others' strong points and close the gap . Those who need the above interview questions can click on the card below to scan the code for free .