Articles
android

Jetpack Compose Runtime: the foundation of declarative UI

This is the 7th day I participated in the Wenwen Challenge. For details of the event, please view: Wenwen Challenge There is currently an ongoing Jetpack Compose Chinese manual project, which aims to help developers better understand and master the Compose framework. It is still in the process of opening up wasteland. Welcome everyone to pay attention and join! This article has been included in the manual, welcome to check compose.runtime Jetpack Compose is not just a UI framework, but also a g

... Levi
schedule 16 min read
android

Chapter 3 of "Spring Handbook Column": First show your skills, use design patterns to realize the definition, registration, and acquisition of Beans

Author: Small Fu brother blog: bugstack.cn Precipitate, share, grow, so that you and others can gain something! I. Introduction Can you foresee design issues for complex content? To be fair, no matter whether the product function is complex or not, a large part of programmers will write a bunch of if...else to complete the development andsmoothlyonline. This is mainly because it is impossible to foresee the current needs, whether the development is long-term, whether the flow is huge, and whethe

... Kaylee
schedule 15 min read
android

A more comprehensive Git command manual, covering almost all daily usage scenarios (medium)

1 Git tools 1.1 Single submission 1.1.1 Log Reference Show the specific information of a certain submission, whereshowAfter that is the partial checksum of a certain submission. git show 9fceb0Copy code View the last commit object of a branch. git show masterCopy code View the checksum of the commit object pointed to by a branch. git rev-parse master copy the code be usable@{n}To quotegit reflogRecords output in, whereHEAD@{n}If it is a commit record, output the commit record information, if it

... Molly
schedule 37 min read
android

Take you into cloud-native technology: exploration and practice of cloud-native open operation and maintenance system

This article is a summary and overview of the first stage of cloud-native open collaboration technology exploration and practice. Ant basic technology has been continuously and deeply advancing the evolution of comprehensive cloud native technology for more than 3 years. We have installed online and offline computing resources into a computer, and the service system has been resolved through mesh ideas and technical means. Coupling, it can be said that the cloud native technology has been fully

... Asher
schedule 32 min read
android

Jetpack AAC complete analysis (3)-ViewModel

1. Introduction to ViewModel ViewModel is an important component of Jetpack AAC, and it also has an abstract class of the same name. ViewModel, which means view model, that is, to prepare data model interface . The simple understanding is that ViewModel provides data for the UI layer. The official document is defined as follows: ViewModel stores and manages interface-related data in a life-cycle-oriented way. (effect) The ViewModel class allows data to persist after configuration changes such as

... Luis
schedule 10 min read
coder_life

The beauty of data structure and algorithm-tree, binary tree, red-black tree

tree Common terms for trees Used to connect to indicate the relationship between adjacent nodes, we call it the parent-child relationship . A Node B node is a parent node , B Node A node is the child node . The parent nodes of the three nodes B, C, and D are the same node, so they are called sibling nodes . We call the node without a parent node the root node , which is the node E in the graph. We call nodes without child nodes as leaf nodes or leaf nodes. For example, G, H, I, J, K, and L in th

... Sophia
schedule 22 min read
coder_life

Solution to Top-k Problem

Article Directory Problem Description The smallest number of k 1. Violent ranking method 2. Big root pile, small root pile 3. Quick selection K points closest to the origin Problem Description The so-called Top-K problem refers to returning the largest/smallest K elements in a given data structure, which may be its own elements or elements in the result of an operation. The following is a simple to explain how to solve this kind of problem. The smallest number of k Enter the integer array arr an

... Andrea
schedule 9 min read
coder_life

Decoding and drawing of RTMP/RTSP player development series for Android platform

This article mainly introduces the decoding and drawing related parts of the RTMP/RTSP player on the Android platform ( Github ). decoding When it comes to decoding, everyone knows software and hardware solutions, and even some companies feel that hard decoding is universal enough, and slowly abandon soft solutions. If you consider equipment matching, both software and hard decoding are supported, which is a good choice. For this reason, Daniel When the live SDK was developing this piece, the cl

... Jackson
schedule 12 min read
coder_life

Challenge the 10 most difficult Java interview questions (with answers)

This is a list of the 10 most difficult Java interview questions I have collected. These problems mainly come from the core part of Java and do not involve Java EE related issues. You may know the answers to these difficult Java questions, or feel that these are not enough to challenge your Java knowledge, but these questions are easy to be asked in various Java interviews, and many including my friends and colleagues Programmers find it difficult to answer. 1. Why are waiting and notification d

... Adrian
schedule 43 min read
coder_life

Fun python | drawing piggy page step by step

WeChat public account: Python concentration camp repeat simple things, insist on doing repetitive things, and do things with heart; yours must be my motivation for persistence. If this article is helpful to you, please pay attention! Define global attributes 1 # Import turtle drawing library 2 3 import turtle as tle 4 5 class peppa_turtle: 6 7 # Initialize global attributes 8 9 def __init__ ( self ): 10 11 self.tle = tle 12 13 # #Global brush attribute settings 14 15 # Settings The size of the p

... Wesley
schedule 11 min read
dev_tools

Parameter verification artifact hibernate-validator with unified exception handling

Traditional parameter verification I believe that everyone has a headache during the development process to verify the parameters passed by the front end, because sometimes the interface requires a lot of parameters. In ancient times, our verification method should be like this: @PostMapping("/order/submit") public void submit(@RequestBody OrderRequest order){ if(order.getParam1() == null){ throw new XXXException("xxx cannot be empty"); } else if(order.getParam2() == null){ throw new XXXExceptio

... Bryson
schedule 14 min read
dev_tools

R language multiple stepwise regression model to analyze house prices and wine prices: choose the most suitable predictor variables

Original link: tecdat.cn/?p=19405  Original source: Tuoduan Data Tribe Official Account     Including more predictors is not free: there is a price to pay in terms of more variability in coefficient estimates, more difficult interpretation, and the possibility of including highly dependent predictors. Indeed, for the sample size , the maximum number of predictors that can be considered in a linear model  is p . Or equivalently, using the predictor p to fit the model requires

... Jack
schedule 29 min read
dev_tools

Knock knock knock review summary

Hello, everyone. I m Miss Hu Piaomiao. The following is a summary note of my usual study and interviews during the years I worked as a front-end. I hope some friends will point out that if it is helpful to you, it will be even better. I hope we can all move towards our goals. Come on! 1 Same-origin strategy The so-called same-origin policy refers to the browser's restriction on the access methods of browsers from different sources, and redirection and form submission will not be restricted by th

... Leonardo
schedule 89 min read
dev_tools

Babylon.js 1

ljzc002.github.io/test/Spacet qe github.com/ljzc002/ljz github UI   spacetestwp2.html 1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title> </title> 6 <link href="../../CSS/newland.css" rel="stylesheet"> 7 <script src="../../JS/LIB/babylon.max.js"></script><!--Babylon.js babylon , gltf --> 8 <script src="../../JS/LIB/babylon.gui.min.js"></script><!--gui --> 9 <script src="../../JS/LI

... Bryson
schedule 20 min read
dev_tools

Cookie of Java Session Technology

@[TOC] 1 Conversation technology 1.1 Overview of Session Management 1.1.1 What is a session The session here refers to a call process in web development. When the browser is opened and the website address is accessed, the session starts. When the browser is closed (or the expiration time is reached), the session ends. for example: For example, you are calling a family member, and suddenly the courier delivering the courier knocks on the door. You put down the phone and open the door. After recei

... Gabrielle
schedule 11 min read
programming

Introduction to Redis-Data Types: Detailed Explanation of 5 Basic Data Type

All keys in Redis are strings. When we talk about the basic data structure, we are discussing the data types of stored values, mainly including 5 common data types: String, List, Set, Zset, Hash Introduction to Redis-Data Types: Detailed Explanation of 5 Basic Data Type Introduction to Redis data structure Detailed explanation of basic data structure String List list Set collection Hash Zset ordered set Reference article Introduction to Redis data structure There are many basic Redis articles.

... Eli
schedule 16 min read
programming

Is this something I can watch for free? Re-engraving classic games hand in hand

Starter: Is this something I can watch for free? Re-engraving classic games hand in hand Game demo: classic game re-engraved version Preface Because the author is just an ordinary page boy, not a developer belonging to the game industry. I usually write some small games just because of my interest, and I often get some small ideas in my mind. So a lot of knowledge is just pieced together by groping. Therefore, this article is just to introduce to you how I went from zero to one to complete a pla

... Timothy
schedule 17 min read
programming

The use of gulp (four): processing css

This is the 17th day of my participation in the Wenwen Challenge. For details of the event, please view: Wenwen Challenge Preface In the last article on the use of gulp (3): Handling js article introduced how gulp handles html. In this article we will introduce how gulp handles css. Output css We create a css directory in the src directory, and create a new index.css file in it, and write the following test code in it. body { background : yellowgreen; } Copy code src/index.html introduces index.

... Kaiden
schedule 9 min read
programming

js

. 6+1 undefined null Boolean numbe string symbol object function Array Date ( ) 1.1 typeof , number string boolean undefined symbol object,array,null. object function function 1.undefined undefined, ; a typeof a ;//undefined 2. null typeof null 'Object'; null null null == undefined ; true ===, null undefined == null==0 ;//false !null==true;//true if 3.Boolean 0/NaN/null/undefined false true 4.number 5.string 1 toString(): null undefined tostring() 2.String(): null undefined String() . 3. +" ":

... Faith
schedule 9 min read
programming

Common bad smells and refactoring techniques in the code (part 2)

The book continues above. Common bad smells and refactoring techniques in the code (part 1) Primitive Obsession class Product { constructor ( data ) { this ._name = data.name; this ._price = data.price; /* ... */ } get name () { return this .name; } /* ... */ get price () { return ` ${ this .priceCount} ${ this .priceSuffix} ` ; } get priceCount () { return parseFloat ( this ._price.slice( 1 )); } GET priceUnit () { Switch ( the this ._price.slice ( 0 , . 1 )) { Case ' ' : return 'CNY' ; Case '

... Alyssa
schedule 50 min read
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