android

Niu X's jQuery

How awesome is jQuery? jQuery was released in 2006 and is by far the longest-lived library for the front end. It is also the most widely used library in the world, 80% of the top 100,000 websites in the world are still using jQuery This is the jQuery usage data as of March of this year Why is jQuery so awesome? Let's take a look at the most notable features of jQuery first Easy to use How simple is it? for example: If Query is not used, JS event listener (compatible with IE6) should be written l

Brandon

schedule 19 min read

android

OkHttp source code reading guide

The content of this article: OkHttp process guide The role of each interceptor Implementation of Https Dns Implementation of Http1.1 and HTTP2 The role and realization of the connection pool OkHttp process Class Diagram The class diagram here only draws the class diagram in the chain of responsibility pattern process, and the more important network UML diagram will be in the ConnectInterceptor below flow chart This flow chart only involves a simple process, not specific details. What is highligh

Natalie

schedule 17 min read

android

Will toB SaaS become the next "number industry" in Suzhou?

The 2020 epidemic has accelerated the process of digitalization from domestic to international, and the digital economy has also become a new strong variable for business operations. According to statistics from the China Academy of Information and Communications Technology, the overall scale of the digital economy has accounted for 36.2% of GDP in 2019. According to data from the National Cyberspace Administration of China: In 2020, the added value of the core capacity of the digital economy w

Greyson

schedule 28 min read

android

Share a wave of your own Android interview questions in 2021

How does RecyclerView work? Different from ListView, recyclebin mechanism Blog guide: juejin.cn/post/695029... Principle of Event Distribution Screen refresh mechanism (keywords vsync Cherorghapher SurfaceFlinger, etc.) Why not recommend the new Thread () method to create threads, thread pool advantages How to create a thread in normal times, how to realize it internally in rxjava Thread pool+Handler How to do drawing optimization, how to realize lazy loading of recyclerview item (such as inser

Jude

schedule 18 min read

android

After performing performance tests on Kafka and Pulsar, Lakala replaced the messaging platform with Pulsar.

Founded in 2005, Lakala Payment is a leading third-party payment company in China. It is committed to integrating information technology, serving offline entities, starting from payment, and empowering small, medium and micro merchants in all dimensions. In 2011, it became one of the first batch of companies to obtain the "Payment Business License", and in the first half of 2019, it served more than 21 million merchants. On April 25, 2019, it was listed on ChiNext. Functional Requirements Due t

Summer

schedule 18 min read

coder_life

Worried about getting an interviewer? Get a thorough understanding of this MySQL interview exercise to help you win offers from major manufacturers

Hello, today I will share with you the Mysql interview exercises for children's shoes, please take out a small book and write them down Three database paradigms The first normal form (1NF) has no duplicate columns The so-called first normal form (1NF) means that each column of the database table is an inseparable basic data item. There cannot be multiple values in the same column, that is, an attribute in an entity cannot have multiple values or duplicate attributes . If there are duplicate attr

Brandon

schedule 29 min read

coder_life

Heavy! The Nginx full solution note that has exploded in Huawei internal forums has just been launched, and the collection has exceeded 10,000

cHello, today I will share Nginx with all children's shoes, please take out a small book and write it down! 1. Introduction to Nginx 1.1 Nginx overview Nginx ("engine x") is a high-performance HTTP and reverse proxy server, which is characterized by less memory and strong concurrency. In fact, the concurrency of nginx does perform better in the same type of web server. It is used in mainland China Users of nginx website include: Baidu, Jingdong, Sina, Netease, Tencent, Taobao, etc. 1.2 Nginx as

Sydney

schedule 16 min read

coder_life

The MATLAB Realization of Particle Swarm Algorithm for Finding the Maximum Value of Unary Function

In the previous essay that introduced the particle swarm algorithm to realize the grouping backpack in detail, the main idea of the particle swarm algorithm has been introduced in detail. If you have mastered how to use the particle swarm algorithm to realize the grouping backpack, you should modify it into a unary function to find the best The application of value is simply a piece of cake. Here is a copy of the general idea of using the particle swarm algorithm to achieve grouping backpacks su

Alan

schedule 12 min read

coder_life

Turning to Wind and Rain at the age of 27 3-Breaking the curse of 35 years old, programmer transformation road

Second child Talking for ten months: it must be the daughter, and finally brought it to the ground The year 2020 is really comfortable, and I have been running hard for several years in a row, and I have always wanted to take a break. Work is stable and leisurely, my wife also finds a job, the work place is very close to me, and my son goes to kindergarten to take over. Drive 40 minutes to get off work, write code in the morning, visit the community in the afternoon, and play a few dotas at nigh

Luke

schedule 31 min read

coder_life

Tuning of hbase

One, the design of the table 1.1 Pre-Creating Regions By default, a region partition is automatically created when the HBase table is created. When data is imported, all HBase clients write data to this region, and the region is not split until the region is large enough. One way to speed up the batch writing speed is to create some empty regions in advance , so that when data is written to HBase, it will load balance the data in the cluster according to the region partition . Below is an exampl

Ella

schedule 12 min read

dev_tools

AOP-implementation principle

1. Basic theoretical knowledge Here is the basic knowledge of AOP; AOP: A straightforward and popular understanding is aspect-oriented programming; there are many aspects of aspect-oriented programming on the Internet, so I won t elaborate on it here; in fact, the real role of aspects is to use very loosely coupled logic on a certain completed function. Ways to add a series of enhanced logic processing in scenarios such as before, after, and exceptions; As far as AOP is concerned, it is achieved

Kaiden

schedule 28 min read

dev_tools

SynchronousQueue source code analysis (based on Java 8)

Welcome everyone to pay attention to github.com/hsfxuebao/j... , I hope it will be helpful to you, if you think it is possible, please give me some Star 1. Introduction SynchronousQueue is a member of the BlockingQueue family. Unlike other members, it has the following characteristics: 1. The entire queue has no capacity, which means that every time you put the value in, you must wait for the corresponding consumer to take the data before you can put the data again 2. Queue corresponding to pee

Benjamin

schedule 19 min read

dev_tools

[Leaf classification] Based on matlab GUI BP neural network plant leaf recognition classification [including Matlab source code 916]

1. Introduction 1 Overview BP (Back Propagation) neural network was proposed in 1986 by a scientific research group led by Rumelhart and McCelland. See their paper Learning representations by back-propagating errors published on Nature. BP neural network is a multi-layer feedforward network trained by error back propagation algorithm, and it is one of the most widely used neural network models. The BP network can learn and store a large number of input-output pattern mapping relationships withou

Ezekiel

schedule 19 min read

dev_tools

The most powerful IT companies in Beijing are all here!

In the past, migrant workers collected Wuhan, Chengdu, Shanghai, Hefei and other cities. Today is Beijing, and other cities will be updated later. The most powerful IT companies in Chengdu are all here The most powerful IT companies in Wuhan are all here What are the great Internet companies in Shanghai? The most powerful IT companies in Hefei are all here Welcome sustained attention to road workers brother of technology as much as possible for everyone to complete the consolidation of Internet

Lucas

schedule 40 min read

dev_tools

Depth First Search, DFS Breath First Search leetcode DFS BFS V A tree is a special case of a graph (a connected acyclic graph is a tree). Next, let's take a look at how to traverse the tree using depth-first traversal. 1. We start traversing from the root node 1, and its adjacent nodes are 2, 3, 4. First traverse node 2, then traverse the child node 5 of 2, and then traverse the child node 9 of 5. 2. A road in the above figure has been reached to the end (9 is a leaf node, and there are no more

Cora

schedule 14 min read

programming

(Update time) March 28, 2021 python basics (use of threads)

1. The use of threads 1. Import the thread module #Import threading module import threadingCopy code 2. Thread parameter description Thread([group [, target [, name [, args [, kwargs]]]]]) group: Thread group, currently only None can be used target: the name of the target task to be executed args: pass parameters to the execution task in the form of tuples kwargs: pass parameters to the execution task in a dictionary name: thread name, generally do not need to be set 3. Start the thread Start th

Quinn

schedule 10 min read

programming

JavaScript

JavaScript freecodecamp JavaScript JavaScript duck let duck = { name: "Aflac", numLegs: 2 }; duck name Aflac numLegs 2 let duck = { name: "Aflac", numLegs: 2 }; console.log(duck.name); duck name Aflac method duck let duck = { name: "Aflac", numLegs: 2, sayName: function() {return "The name of this duck is " + duck.name + ".";} }; duck.sayName(); sayName duck duck.name name this duck return duck.name name sayName: function() {return "The name of this duck is " + duck.name + ".";} this let duck =

Calvin

schedule 6 min read

programming

Spring Boot ( ) refresh

Spring -- refresh refresh Spring Bean Spring refresh refresh SpringApplication.run(String... args) // SpringApplication # run(String... args) # 311-313 public ConfigurableApplicationContext run(String... args) { // prepareContext(context, environment, listeners, applicationArguments, printedBanner); refreshContext(context); afterRefresh(context, applicationArguments); // return context; } refreshContext(context) // SpringApplication # refreshContext(ConfigurableApplicationContext context) # 390

Calvin

schedule 5 min read

programming

Ridge regression, lasso regression, principal component regression in R language: linear model selection and regularization

Original link: tecdat.cn/?p=9913 Original source: Tuoduan Data Tribe Official Account     Overview and definition In this article, we will consider some alternative fitting methods for linear models, in addition to the usual  ordinary least squares method . These alternative methods can sometimes provide better prediction accuracy and model interpretability. Prediction accuracy : linear, ordinary least square estimation will have low deviation. OLS also performed well,  n &nb

Camden

schedule 28 min read

programming

TypeScript study notes

One, TypeScript definition TypeScript is a superset of JavaScript and extends the syntax of JavaScript. TypeScript provides static type checking at compile time through type annotations. Two, TypeScript basic types 2.1 Boolean type //Assign variables directly after declaration let c: boolean = false; Copy code If the variable declaration and assignment are carried out at the same time, ts can automatically check the type of the variable let c = false; c = true; // c = 123; This line of code will

Lily

schedule 17 min read