Android high frequency network interview topic must know and be able to compare Android development environment

1、 Support http2, All requests to a machine share the same socket

2、 Built in connection pool , Support connection reuse , Reduce the delay

3、 Support transparent gzip Compress the response body

GZIP It is a technology for website compression and acceleration , It can speed up the opening of our website after opening , The principle is compressed by the server , The principle of fast decompression of client browser , It can greatly reduce the traffic of the website

open GZIP What are the benefits ？Gzip After opening, the data output to the user's browser will be compressed , This will reduce the amount of data transmitted over the network , Improve the speed of the browser startup page .

4、 Avoid duplicate requests by caching

Mandatory cache

The first time the client requests data , The server returns the expiration time of the cache （ Through fields Expires And Cache-Control identification ）, Subsequently, if the cache does not expire, you can directly use the cache , There is no need to request the server ; Otherwise, request data from the server .

Compare cache

When comparing caches , Every request needs to interact with the server , The server determines whether the cache can be used .

5、 Automatically retry other requests of the host when the request fails ip, Automatic redirection

6、 Easy to use API

2、 seen OkHttp Source code of , Just briefly

First of all , Through a builder pattern （Request.Builder） Build all the request, And then distribute it to Dispatcher( The dispenser );

second ,Dispatcher And then request Distribute to HttpEngine（ Real working class ） in ,HttpEngine First, let's see if this request has cache( cache ), If you have a cache , Just get the information from the cache , And back to response; If there is no cache ,HttpEngine Just put request Distribute to ConnectionPool（ Connection pool ） in ;

Third , stay ConnectionPool（ Connection pool ） in , adopt Connection Send a request , First choose Route（ route ） and Platfrom( platform ), Then arrive at Server（Socket）, Get Data, Then return response.

3、OkHttp Use

1、 establish OkHttpClient object ：OkHttpClient client = new OkHttpClient();

2、 Create a network request ：Request request = new Request.Builder() .url(“http://sethfeng.github.io/index.html”) .build();

3、 obtain Call object ：Call call = client.newCall(request); // What is actually created is a RealCall object ,RealCall One of them is right client References to objects

4、 Send a request , Get the returned data

Send synchronization request ：Response response = call.excute();

Send asynchronous request ：

call.enqueue(new Callback() {

@Override

public void onFailure(Request request, IOException e) {

…

}

@Override

public void onResponse(Response response) throws IOException {

…

}

});

4、volley

Last

Actually Android There are so many knowledge points in development , There are still so many things to ask about in the interview . So there's no other trick to an interview , It depends on how well you are prepared for these knowledge points .so, When you go out for an interview, you should first see which stage you have reviewed .

The following figure shows my accumulated experience over the years tencent 、 headlines 、 Ali 、 Meituan 、 Byte skipping and so on 2019-2021 High frequency interview questions in , Bloggers also organized these technical points into videos and PDF（ In fact, it took a lot more energy than expected ）, Contains the context of knowledge + A lot of details

above 【 Interview questions for senior engineers in large factories over the years 】、【Android Advanced teaching video 】、【Android Learn advanced knowledge points PDF】 They are free to share with you . If necessary , Click on **【Android Architecture video +BATJ Interview topics PDF+ Learning notes 】** Free access to .

E4%BA%9B%EF%BC%9F%E5%A6%82%E4%BD%95%E9%9D%A2%E8%AF%95%E6%8B%BF%E9%AB%98%E8%96%AA%EF%BC%81.md)** Free access to .

Sorting is not easy to , Please pay attention and forward it to me , thank you ！ I wish everyone can get their favorite job .