The cold winter can't stop the determination to enter the big factory. The Android interview has a complete knowledge structure, and everything you need to master in the interview is here!

Preface

It's winter every year , Every year I can't stop one Android The programmer's determination to pursue the big factory . Want to enter the big factory , What knowledge points do we need to master ？ here , I have sorted out an overall knowledge structure for you . The whole includes Java、Android、 Algorithm 、 Network, etc , And I also recommended books and blogs related to this knowledge point under the corresponding knowledge point . I hope that after reading , It can help you improve and organize your knowledge system . I wish you all an early entry into your ideal company ~~

Be careful , The whole article is a summary of knowledge points , Without the answer , We need to see more source code , Knowledge can only be explored and discovered by oneself , Will be precious ！

Java Basic knowledge points

Jvm relevant

• Java Memory structure and partition
• Java Object creation 、 Storage and access
• Java Determine whether the object survives and garbage collection algorithm （GC）
• Jvm Common garbage collectors in
• Java Class loading process
• Java Class loader （ Parent delegation model ）

Recommended reading ：

• 《 In depth understanding of Java virtual machine JVM Advanced features and best practices 》 Chapter two Java Memory area and memory overflow exception
• 《 In depth understanding of Java virtual machine JVM Advanced features and best practices 》 The third chapter Garbage collector and memory allocation strategy
• 《 In depth understanding of Java virtual machine JVM Advanced features and best practices 》 Chapter six Class file structure
• 《 In depth understanding of Java virtual machine JVM Advanced features and best practices 》 Chapter vii. Virtual machine class loading mechanism
• 《Java Virtual machine specification JAVA SE 8 edition 》

Set correlation

• ArrayList analysis
• LinkedList analysis
• HashMap analysis
• HashTable analysis
• LinkedHashMap analysis
• HashSet analysis
• LinkedHashSet analysis
• ArrayMap、SparseMap、 And HashMap Comparison of
• ConcurrentHashMap analysis

Recommended reading

• To understand through and through HashTable
• Meituan technical team -Java8 A new understanding of the series HashMap
• Map review （ Two ）： To understand through and through LinkedHashMap
• 《Java The art of concurrent programming 》 Chapter six 6.1 section CocurrrentHashMap（ be based on JDK 1.6,1.7 Analytical ） Implementation principle and Application
• Explain profound theories in simple language ConcurrentHashMap1.8

Concurrent correlation

• Java Memory model
• volatile principle
• Synchronized Principle
• AQS principle
• Condition principle
• ReentrantLock principle
• Fair lock and unfair lock
• ReentrantReadWriteLock principle

Recommended reading ：

• 《Java The art of concurrent programming 》 Chapter two Java The underlying implementation principle of concurrency mechanism
• 《Java The art of concurrent programming 》 The third chapter Memory model
• 《Java The art of concurrent programming 》 The fifth chapter Java In the lock
• Java Concurrent programming Java Memory model
• Java Concurrent programming Java CAS operation
• Java Concurrent programming Volatile
• Java Concurrent programming synchronized
• Java Introduction to locking mechanism of concurrent programming
• Java Lock mechanism of concurrent programming Lock Interface
• Java Lock mechanism of concurrent programming AQS(AbstractQueuedSynchronizer)
• Java Lock mechanism of concurrent programming LockSupport Tools
• Java Lock mechanism of concurrent programming Condition Interface
• Java Lock mechanism of concurrent programming reentry lock
• Java Read / write lock of lock mechanism in concurrent programming

Thread related

• Start and end of thread
• Inter thread communication
• wait for / A notification mechanism

Recommended reading ：

• 《Java The art of concurrent programming 》 Chapter four Java The basis of concurrent programming

Thread pool related

• Why thread pools are used
• The internal principle of thread pool
• Several important parameters and flow descriptions in the thread pool
• Several common work queues in thread pool
• Several common thread pools and usage scenarios .

Recommended reading ：《Java The art of concurrent programming 》 Chapter nine Java Thread pool in

IO relevant

• IO Related interview questions -Socket
• IO Related interview questions -BIO／NIO

Recommended reading ：

• NIO Related basic article 1
• NIO Related basic part II
• NIO Related basic chapter three
• 《UNIX Network programming , volume 1： Socket networking API The third edition 》 Chapter six I/O Reuse ：select and poll
• 《 In depth understanding of Java virtual machine JVM Advanced features and best practices 》 Chapter two Java Memory area and memory overflow exception 2.7 section Introduction to direct memory

Android Basic knowledge points

Activity relevant

• Life cycle under typical conditions
• Abnormal life cycle
• Data saving under abnormal conditions
• Jump to a... In all cases Activity When it comes to goals Activity And current Activity Life cycle of
• Activity Startup mode and application scenario
• Process and application life cycle

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter one Activity Life cycle and startup mode of
• 《Android Exploration of development Art 》 Chapter nine 9.2 section Activity Working process of
• Google- Process and application life cycle
• Google- Task and return stack

Service relevant

• Service Definition and function of
• Service Two ways to start startService、 bindService Difference and life cycle
• Service Three implementations of binding services , Expand Binder class 、 Use Messenger、 Use AIDL
• On the conversion between startup service and binding service Bind the service first and then start the service 、 Start the service first and then bind the service
• service Service With threads Thread The difference between
• Android 5.0 The above implicit startup problem and its solution
• How to ensure that the service is not killed
• IntentService Use and principle of

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter nine 9.3 section Service Working process of
• About Android Service Really full explanation , Everything you need to know
• Android The multithreading IntentService Complete explanation
• Android The multithreading HandlerThread Complete explanation

BroadcastReceiver relevant

• BroadcastReceiver Definition and function 、 Application scenarios
• BroadcastReceiver How to register , Static mode 、 Dynamic mode
• BroadcastReceiver Timing of registration and cancellation
• BroadcastReceiver Different types of , General broadcasting , System broadcast 、 Ordered broadcasting 、 Sticky radio 、 Application class broadcast

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter nine 9.4 section BroadcastReceiver Working process of
• BroadcastReceiver The most comprehensive analysis in history
• Broadcast in 7.0、8.0、9.0 Next fit

Fragment relevant

• Fragment Life cycle
• Fragment Lazy loading
• Fragment Communication between
• FragmentPagerAdapter And FragmentStatePagerAdapter The difference between
• Why not suggest directly using new Fragment Pass in data in the same way

Recommended reading ：

• Fragment Full analysis series （ One ）： The pit that I stepped on in those years
• Google-Fragment overview
• Google- And others Fragment signal communication

Serialization related

• Definition and difference between serialization and deserialization
• Serializable in serialVersionUID And transient The role of keywords
• serialize ：Parcelable and Serializable differences

Recommended reading ：

• Serialization and deserialization Parcelable and Serializable elementary analysis
• 《Android Exploration of development Art 》 Chapter two IPC Introduction to basic concepts

IPC relevant

• stay Android Under what circumstances will multi process mode be used , How to start multiple processes
• Android Why use Binder As IPC Mechanism
• IPC Commonly used way Use Bundle、 Use file sharing 、 Use Messenger、 Use AIDL、 Use ContentProvider、 Use Socket
• AIDL The semantics of the
• AIDL How to create
• AIDL Generate Java Detailed analysis of the documents

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter two IPC Mechanism
• 《 As deep as understanding LINUX kernel The third edition covers 2.6 edition 》 The third chapter process 3.2 Section process descriptor
• written Android Application engineer's Binder Principle analysis
• If you need to know more about , recommend GitYuan Greatly Binder Series articles

View Event mechanism related

• View The coordinate system of
• View There are several ways to slide , Use ScrollTo/ScrollBy、 Use animation 、 Change layout parameters
• Principle and Realization of elastic sliding
• View Event distribution mechanism of , Delivery rules of click event , Event distribution source code interpretation
• Scenarios and solutions for handling sliding conflicts

Recommended reading ：

• 《Android Exploration of development Art 》 The third chapter View Event system of

View Rendering correlation

• DecorView、Window、ViewRootImpl And so on
• MeasureSpec Concept
• View workflow ,measure The process 、layout The process 、draw The process
• Customize View What to pay attention to
• Activity、Window、View The relationship between the three

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter four View How it works
• 《Android Exploration of development Art 》 Chapter viii. understand Window and WindowManager
• Android Custom control trilogy article index

View Animation related

• Common animations View Animation （ Patch animation ）、 Attribute animation and frame animation
• The difference between patching animation and attribute animation
• Differentiator and estimator understand
• How attribute animation works

Recommended reading ：

• Android Custom control trilogy article index
• 《Android Exploration of development Art 》 Chapter vii. Android In depth analysis of animation

Handler relevant

• Handler Mechanism ThreadLocal
• Handler Mechanism Looper、Handler、 How message queues understand
• Handler Mechanism Message Sending and taking out
• Handler Mechanism Message And Message Recycling mechanism of
• Handler Exit of circular message queue
• Handler Memory leak of mechanism
• Handler Mechanism IdleHandle Understanding and use of

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter ten 10.2 section Android The message mechanism of
• IdleHandle The idea of -----> You know, android Of MessageQueue.IdleHandler Do you ？
• Handler Frequently asked questions in interviews -----> Do you really understand Handler Do you ？Handler Question and answer

AsyncTask relevant

• AsyncTask How to use and pay attention to
• AsyncTask Several important methods doInBackgound、* onProgressUpdate、onPostExecute etc.
• AsyncTask Working principle and source code understanding

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter 11 Android Thread and thread pool
• 《Java The art of concurrent programming 》 Chapter nine Java Thread pool in , Chapter ten Executor frame

Bitmap Compression recovery related

• Bitmap Memory occupied
• Common ways to compress pictures
• LruCache principle
• DiskLruCache principle
• LinkedHashMap principle

Recommended reading ：

• Picture memory formula ： The resolution of the * Each pixel size , Rigorous ？
• Luban picture compression
• Map review （ Two ）： To understand through and through LinkedHashMap

ListView And RecyclerView relevant

• ListView Principle and reuse mechanism
• ListView and RecyclerView The difference between

Recommended reading ：

• Android ListView The working principle is completely analyzed , Take you to understand the source code thoroughly
• In depth understanding of Android Caching mechanism in ( Two )RecyclerView Follow ListView Cache mechanism comparison

Data storage

• Common database framework GreenDao, official Room
• Database data migration
• GreenDao One on one , One to many , Many to many relationship
• SharedPreferences Use and source code ,commit And apply() Differences in methods

Recommended reading ：

• Database foundation 1
• Database foundation 2
• Database foundation 3
• GreenDao Official help files
• Interview questions ： At a glance SharedPreferences
• GreenDao Database migration help class MigrationHelper

Android Open source framework knowledge points

OkHttp relevant

• OkHttp The advantages of
• OkHttp The whole process of executing the request
• OkHttp Interceptors in
• OkHttp The understanding of synchronous and asynchronous requests and their source code
• OkHttp Design patterns involved in
• OkHttp Underlying network request implementation ,socket still URLConnection

Recommended reading ：

• Remove wheel series - Demolition OkHttp

Retrofit relevant

• Retrofit The whole process of executing the request
• Retrofit in ConverterFactory、CallAdapterFactory The understanding of the
• Retrofit in CallAdapter Adapter mode for

Recommended reading ：

• Remove wheel series ： Demolition Retrofit

RxJava relevant

• RxJava Common creation operators create、from、just、interval、range etc.
• RxJava Common combinations 、 Merge operators combineLatest、join、merge、zip etc.
• RxJava Error handling operators onErrorReturn、onErrorResumeNext、onExceptionResumeNext etc.
• RxJava Filter operators filter、ofType、sample、take etc.
• Rxjava Understanding of back pressure
• RxJava Use in actual development ： Network request polling 、 Network request nested callback 、 From disk / In memory cache Get cache data, etc

Recommended reading ：

• Android Rxjava： This is an article Clear & Understandable Rxjava Introductory tutorial

Glide relevant

• Glide The implementation process of
• Glide Cache mechanism
• Glide Picture conversion
• Glide Picture loading function with progress
• Glide Memory 、 Disk caching , Priority use

Recommended reading ：

• Android Image loading framework is the most complete analysis （ One ）,Glide The basic usage of
• Android Image loading framework is the most complete analysis （ Two ）, From the perspective of source code Glide The implementation process of
• Android Image loading framework is the most complete analysis （ 3、 ... and ）, In depth exploration Glide Cache mechanism
• Android Image loading framework is the most complete analysis （ Four ）, Get along well with Glide Call back and monitor
• Android Image loading framework is the most complete analysis （ 5、 ... and ）,Glide Powerful image transformation function
• Android Image loading framework is the most complete analysis （ 6、 ... and ）, To explore the Glide Custom module function of

ButterKnife relevant

• Java Annotations associated Annotation
• Java Annotation related APT Tools
• ButterKnife Annotation framework principle

Recommended reading ：

• Android Annotation series APT Tools （ 3、 ... and ）
• Android Annotation series Annotation（ Two ）
• ButterKnife Principle analysis

EventBus relevant

• EventBus principle , And the use of index classes

Recommended reading ：

• Android Annotation series APT Tools （ 3、 ... and ）
• Android Annotation series Annotation（ Two ）
• tencent Bugly dried food - The old driver taught you “ Whirlwind ”EventBus3

Android performance optimization

• performance optimization ： Layout optimization 、 Painting optimization 、 Thread optimization, etc
• ANR abnormal ： The main thread performs time-consuming operations , Such as BroadcastReceiver( Foreground broadcast 10s, Background broadcast is 60s)、Service( The front desk 20s, backstage 200s) I haven't finished handling related tasks, etc
• OOM abnormal ： Cause of memory overflow
• Memory leak ： Several scenarios of memory leakage , Such as the leakage caused by singleton mode 、 Leakage caused by static variables 、 Memory leakage caused by attribute animation, etc

Recommended reading ：

• 《Android Exploration of development Art 》 Chapter 15 Android performance optimization
• Memory Profiler Use
• LeakCanary Library related introduction

Android Screen adaptation knowledge points

• Today's headline adaptation
• Width and height qualifier adaptation method
• smallestWidth adapter

Recommended reading ：

• Latin teacher Wu's --Android Currently stable and efficient UI Adaptation scheme
• Today's headline adaptation
• SmallestWidth Qualifier adaptation scheme

Android Pack knowledge points

• Understanding of Android signature
• Gradle Multi channel packaging

Recommended reading ：《Android Gradle Authoritative guide 》

Android Architecture knowledge points

• MVC Architecture design pattern interview question explanation
• MVP Architecture design pattern interview question explanation
• MVVM Architecture design pattern interview question explanation

** Recommended reading ：

• mvp Architecture design
• mvvm Architecture design
• googlesamples/android-architecture

Android Feature knowledge points of different versions

Recommended reading ：

• Android Features in different versions
• Broadcast in 7.0、8.0、9.0 Next fit
• Android 6.0 Adaptation under permissions
• Android 7.0 Apply shared files （FileProvider)
• Android 7.0 How shared files are used

Network knowledge points

• There are three architectures of computer network ,OSI Architecture （7 layer ）、TCP/IP Architecture (4 layer ), Five tier architecture
• TCP Connection management （ Three message handshake , Four message handshake ）
• TCP And UDP The understanding and the difference between
• Http（HyberText Transfer Protocol） Basic concept and message structure
• Http Common error codes
• Http1.0 And Http1.1 And Http2.0 The difference between
• Http in get Ask for something to do with post Differences in requests
• Http in cookie And session The difference between
• Http And Https The difference between
• Https Encryption algorithm related interview questions , Signature certificate , Public key private key 、 Understanding of digital Abstracts

Recommended reading ：

• Architecture --->《 Computer network 7th Edition Xie Xiren 》 Chapter one 1.7.1 Stanza to 1.7.5 section
• TCP Three message handshake and four message handshake --->《 Computer network 7th Edition Xie Xiren 》 The fifth chapter 5.9 section TCP Transportation connection management
• TCP And UDP understand --->《 Computer network 7th Edition Xie Xiren 》 The fifth chapter Transport layer
• 《 Computer network 7th Edition Xie Xiren 》 Chapter six application layer Chapter vii. Network security
• HTTP1.0、HTTP1.1 and HTTP2.0 The difference between
• Clear computer network foundation Learning Guide

Design pattern knowledge points

• The singleton pattern
• Builder Pattern
• Decoration mode
• The strategy pattern
• Template method
• Observer mode
• etc. .....

Recommended reading ：《Android Analysis and practice of source code design pattern 》

Algorithm knowledge points

• Eight common sorting methods
• Calculation of time complexity
• Linked list related algorithm , List flip , List merging, etc
• Binary tree correlation algorithm preamble 、 Middle preface 、 After the sequence traversal （ recursive , iteration ）
• Red and black tree BL Trees
• etc.

Recommended reading ：

• 《Java Data structures and algorithms The second edition 》
• Time complexity learning （ On )
• Time complexity learning （ Next )
• Brush problem ---->LeetCode

Review the route before the interview

The next shared system learning resources are Explain the Internet companies in detail Android The common interview questions are the main line , From the angle of interview, I will introduce you the necessary knowledge , And the practical application of this knowledge point in the project .

Help you build on the present , Reorganize and establish Android Developed knowledge system . Whether you want to improve in the short term Android Internal strength , Break through the ability bottleneck in one's work , Or ready to participate in Android interview , You will get something from this information .

Start with the infrastructure , Divide up 8 There are three modules to step from basic to architect ：

Don't say anything superfluous , Next, I will share a review route for the interview , But if you don't know how to prepare for the interview efficiently , You can refer to my review route , You are welcome to communicate with each other if you have any questions , Come on! ！

First of all, it's super detailed Android Map learning , Because the picture is so big , So I just put out the contents of the secondary directory .

Then we need to sort out the knowledge , Increased reserves ！（Android Seven project learning resources for mobile architects ）

• The necessary skills for an architect to build a foundation ： thorough Java Generic + The notes are simple + Concurrent programming + Data transmission and serialization +Java Principle of virtual machine + Reflection and class loading + A dynamic proxy + Efficient IO
• Android senior UI And FrameWork Source code ： senior UI promotion +Framework Kernel parsing +Android Component kernel + Data persistence
• 360° Comprehensive performance tuning ： Design ideas and code quality optimization + Program performance optimization + Development efficiency optimization
• Interpretation of open source framework design ideas ： Thermal repair design + Plug in framework interpretation + Component frame design + Image loading framework + Network access framework design +RXJava Responsive programming framework design +IOC Architecture design +Android Architecture components Jetpack
• NDK Module development ：NDK Basic knowledge system + Bottom image processing + Audio and video development
• Wechat applet ： Introduction to applet +UI Development +API operation + Wechat docking
• Hybrid Development and Flutter：Html5 Project practice +Flutter Advanced

After sorting out the knowledge , We need to make up for it , So for these knowledge points , I also have a lot of e-books and notes on hand , These notes make a perfect summary of each knowledge point .

Then through the source code to systematically learn

As long as the programmer is , Whether it's Java still Android, If you don't read the source code , Just look at API file , It's just a matter of skin , This is not conducive to the establishment and completion of our knowledge system and the improvement of actual combat technology .

The real ability to exercise is to directly read the source code , Not limited to reading the source code of the major systems , It also includes a variety of excellent open source libraries .

Prepare for the big factory interview questions , Increase the pass rate of large factories

Lasted six months , Sort out the most comprehensive Android interview questions on the market .

1. You can directly browse the required knowledge points through the directory index , Leak filling . 2. The five pointed star number indicates the frequency of the interview , Represents the important recommendation index

All of the above are free to share with you , Need a full version of friends , Click here to see the whole thing . Or click 【 here 】 See how to get .