It’s October 2017, and there are only a few months left before 2018. Many people are estimated to be on the way to job-hunting. Nonsense not to say, directly on the dry goods, because it is arranged in the network, do not mark the original, I hope we share and forward to the need of the students.

alibaba

  • LRUCache principle

  • Picture loading principle

  • Modular implementation (benefits, reasons)

  • JVM

  • Video encryption transmission

  • Statistics startup time, standard

  • How to maintain the stability of the application

  • ThreadLocal principle

  • Talk about this

  • Dynamic layout

  • Hot repair, plug-in

  • HashMap source code,SpareArray principle

  • Performance optimization, how to ensure that the application startup does not lag

  • How to remove duplicate code

  • Is SP process synchronized? Is there any way to synchronize

  • Introduce SurfView

  • Implementation principles of HashMap and ConcurrentHashMap

  • BroadcastReceiver, LocalBroadcastReceiver

  • Bundle mechanism

  • Handler mechanism

  • Android event passing mechanism

  • Interthread operation List

  • The App startup process starts from clicking on the desktop

  • Dynamic loading

  • Class loader

  • OSGI

  • Https request slow solution, DNS, carry data, direct access IP

  • GC collection strategy

  • Draw the big picture of Android

  • Describe what happens when you click the Build button in Android Studio

  • Outline what happens when an application is installed on a phone;

  • Basic understanding of Dalvik and ART virtual machine;

  • How inter-process-Communication works on Android;

  • How and why apps are sandboxed;

  • Permissions management system (how the underlying permissions are granted)

  • Process and Application lifecycle;

  • System startup process Zygote process > SystemServer process > Various system services > Application process

  • Recycleview ListView distinction, performance

  • Sort, the implementation of quick sort

  • Trees: An introduction to B+ trees

  • Figure: An interpretation of directed acyclic graphs

  • The difference between TCP/UDP

  • The difference between synchronized and Lock

  • volatile

  • Java thread pool

  • The life cycle of objects in Java

  • Class loading mechanism

  • Parental delegation model

  • Android event distribution mechanism

  • The MVP pattern

  • RxJava

  • The difference between abstract classes and interfaces

  • How does the Set implement Hash prevent collisions

  • JVM memory area open threads affect which memory block

  • Garbage collection object creation, New generation and old generation

  • Binary tree depth traversal and breadth traversal

  • B tree, B plus tree

  • Message mechanism

  • Process scheduling

  • Processes and threads

  • A deadlock

  • Process status

  • JVM memory model

  • Concurrent collections know what

  • ConCurrentHashMap implementation

  • The CAS is introduced

  • There are three ways to start a thread. The run() and start() methods are different

  • The thread pool

  • Introduction to common data structures

  • Judgment ring (guess should be linked list ring)

  • Sort, heap sort implementation

  • List inversion

tencent

  • Synchronized usage

  • Volatile usage

  • Dynamic permission adaptation scheme, concept of permission group

  • How does OKHTTP handle network caching

  • How does bitmap handle large images, such as a 30M large image, and how does it prevent OOM

  • Process to keep alive

  • Listview picture loading disorder principle and solution

  • How do I verify the validity of certificates? Where is symmetric encryption used in HTTPS and where is asymmetric encryption used? Do I know encryption algorithms (such as RSA)

drops

  • MVP

  • Broadcast (dynamic registration and static registration difference, ordered broadcast and standard broadcast)

  • Service Life cycle

  • Handler implementation mechanism (many details need to be paid attention to: how threads create and exit message loops, etc.)

  • Multithreading (Reflections on AsyncTask defects)

  • Database data migration problems

  • Design pattern correlation (e.g. where observer pattern is used in Android, singleton pattern correlation)

  • X apples, one, two, or three apples per day, ask how many days to eat them all

  • The difference between TCP and UDP and the application (three-way handshake and four-way wave) involves some details (for example, how does the client determine that the message it sends is received by the server)

  • Are you familiar with Android JNI development and how jNI calls Java layer code

  • The way in which processes communicate

  • Java annotations

  • Calculates the nesting hierarchy of a view

  • Understanding of project componentization

  • Principle of multi-thread breakpoint continuation

  • Why does Android design contentProviders, process sharing, and thread safety

  • The JVM related

  • Android related optimization (such as memory optimization, network optimization, layout optimization, battery optimization, business optimization)

  • Implementation principle of EventBus

Meituan

  • Static synchronized method multithread access and function, the same class in two synchronized methods, two threads access problems

  • Inner classes and static inner classes and anonymous inner classes, as well as applications in projects

  • How does looper start when handler sends a message to the child thread

  • View Event passing

  • The activity stack

  • How do you know the size of a view when you’re encapsulating it

  • Differences between ArrayList and LinkedList, and application scenarios

  • How do WE start a service and how do services and activities interact with each other

  • Does the drop-down status bar affect the activity life cycle? If a network request is made during onStop, how does it resume during onResume

  • The view to render

Today’s headline

  • The concept of heap in data structure, heap sort

  • The concept of deadlocks, how do you avoid deadlocks

  • ReentrantLock, synchronized, and Volatile (N-side)

  • HashMap

  • SingleTask Startup mode

  • Use of some open source framework, introduced a read source code, internal implementation process.

  • Message mechanism implementation

  • An internal implementation of ReentrantLock

  • App startup crash exception capture

  • Introduction to the event passing mechanism

  • The optimization of ListView

  • Binary tree, give the root node and the target node, find the path from the root node to the target node

  • Model MVP, MVC introduction

  • The implementation of breakpoint continuation

  • Collection of interfaces and concrete implementation classes, introduced

  • TreeMap concrete implementation

  • Synchronized with already

  • Handwritten producer/consumer model

  • Logical address vs. physical address. Why use logical address

  • An unordered, non-repeating array outputs N elements such that the sum of N elements adds up to M, giving time complexity, space complexity. The handwriting algorithms

  • Android process classification

  • The foreground switches to the background, and then back to the foreground, the Activity lifecycle callback method. Pop-up Dialog, lifecycle callback method.

  • The startup mode of the Activity

iQIYI

  • RxJava functions and principles to achieve

  • Use of RecycleView, principle, RecycleView optimization

  • The reason of ANR

  • Four major components

  • Service startup mode

  • How an Activity communicates with a Service

  • How activities communicate with each other

  • Implementation of HashMap, different from HashSet

  • JVM memory model, memory region

  • Java synchronization used keywords, deadlock

  • The MVP pattern

  • Java design pattern, Observer pattern

  • Compare the life cycle between activities and Fragments

  • Broadcast usage scenarios

baidu

  • What should I notice when using Bitmap?

  • Is it possible to try catch in Oom?

  • How do memory leaks occur?

  • What are the similarities and differences between adapter patterns, decorator patterns, and appearance patterns?

  • How is ANR generated?

  • What is the difference between String Buffer and String Builder?

  • How to keep thread safe?

  • Referenced in Java 4

  • Has Jni used it?

  • Have you seen multi-process scenarios before?

  • So handler, what thread is new handler under anywhere

  • Sqlite update to add field statements

  • Bitmap recycler related

  • Will strong references be reclaimed if they are set to NULL?

  • What cache does Glide use?

  • How does Glide memory cache size control?

  • How to ensure the security of multithreading read and write files?

ctrip

  • Activity Start mode

  • The way broadcast is used, the scene

  • The implementation of waking up other processes in App

  • The role and understanding of AndroidManifest

  • The difference between the List, Set, Map

  • How to determine whether a HashSet or HashMap has identical elements

  • Memory regions and garbage collection mechanisms in Java

  • EventBus function, implementation method, method to replace EventBus

  • The main steps of enabling the camera in Android

netease

  • A collection of

  • concurrenthashmap

  • volatile

  • Synchronized with the Lock

  • Java thread pool

  • wait/notify

  • NIO

  • Garbage collector

  • Activity Lifecycle

  • AlertDialog popupWindow, Activity

millet

  • Why is String designed to be immutable?

  • Fragment life cycle in various cases

  • The life cycle of the Activity when the home button is pressed while there is a Dialog on the Activity

  • The life cycle of the Activity in various situations when switching between horizontal and vertical screens

  • The difference between the Application and Activity context objects

  • The role of serialization, and the differences between Android and serialization.

  • Lists and maps are implemented and stored.

  • Static inner class design intent.

  • How can threads be shut down, and how can memory leaks be prevented

360

  • Soft reference and weak reference difference

  • The garbage collection

  • Multithreading: how to use, what problems to pay attention to; Android thread has no upper limit and then mentions the upper limit of the thread pool

  • JVM

  • The lock

  • OOM, memory leak

  • How to analyze and solve ANR

  • LinearLayout, RelativeLayout, FrameLayout features, use scenarios

  • How to implement sliding Fragment

  • How can ViewPager initialize only the current Fragment each time and leave the rest uninitialized

  • What does ListView reuse

  • Mechanisms for interprocess communication

  • AIDL mechanism

  • AsyncTask mechanism

  • How do I cancel AsyncTask

  • serialization

  • Why did Android introduce Parcelable

  • Have you tried to simplify the use of Parcelable

  • AIDL mechanism

  • Project: How to pull live

  • Application Installation Process

An overseas live broadcasting company

  • What’s the difference between thread and process?

  • Why have threads instead of just processes?

  • Algorithm to determine whether a single linked list is looped?

  • How to implement thread synchronization?

  • Hashmap data structure?

  • Arraylist and LinkedList?

  • Object equal and hashCode methods overwritten. Why?

  • How does a Hashmap put data?

  • Briefly describes the IPC?

  • How data is passed between fragments?

  • TCP wave four times

  • Threadlocal principle

  • Possible causes of memory leaks?

  • How do I analyze memory leaks with an IDE?

  • Possible reasons for OOM?

  • Four conditions for thread deadlocks?

  • Differentiator & estimator

  • Describe the message mechanism

  • Interprocess communication?

  • Binder?

  • Distribution of touch events?

  • Describe the entire process of starting an Activity.

  • Okhttp source?

  • RxJava introduction and source code interpretation?

  • How does performance optimization analyze Systrace?

  • Classification of broadcast?

  • Click event is blocked, but passed to the view below, how to operate?

  • Glide source?

  • ActicityThread related?

  • The principle of volatile

  • The principle of the synchronize

  • Principle of the lock

  • Flip a single necklace watch

  • string to integer

  • Merge multiple singly ordered lists (assuming they are all incremental)

Other companies

  • Four major components

  • Data storage in Android

  • The realization of wechat home page

  • The principle of small red dots on wechat messages

  • Find the common element of two sets of non-repeating arrays.

  • Last question extension, massive data, not put in memory, how to figure out.

  • Java String understanding.

  • ArrayList is different from LinkedList

  • Heap sorting process, time complexity, space complexity

  • Time complexity of quicksort, space complexity

  • The use of RxJava, compared to the usual use of asynchronous operations, advantages

  • Principle of Android message mechanism

  • Introduction to Binder mechanism

  • Why can’t I update the UI on a child thread

  • JVM memory model

  • Android process memory allocation, can allocate their own quota of memory

  • Garbage collection is different from calling System.gc()

  • Android event distribution mechanism

  • The implementation of breakpoint continuation

  • What RxJava does, pros and cons