[Linux] dns domain name resolution service

1. DNS 1.1 Introduction to DNS Domain name resolution: (English: Domain Name System, abbreviation: DNS) is a service of the Internet. As a distributed database that maps domain names and IP addresses to each other, it can make people access the Internet more conveniently. DNS uses udp53 and tcp53. Currently,the length limit for each level […]

[Vue Principle Analysis] Virtual DOM

Vue.js is a popular JavaScript framework that uses the concept of virtual DOM to improve performance and development efficiency. Virtual DOM is one of the cores of Vue.js. It builds a lightweight DOM tree in memory instead of directly operating the real DOM, thereby reducing the number of operations on the real DOM and improving […]

[Java tool class] Generate random image verification code and convert it to Base64 code

Article Directory Table of Contents Article Table of Contents Text 1. Directly upload the code 2. Things to note 3. Test 4. Get Base64 code Text 1. Directly upload the code package com.review.demo.util; import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.util.Base64; import java.util.Random; public class ImageCodeCreate { /** * long */ […]

Cross-domain: Use JSONP and WebSocket to achieve cross-domain access

Cross-domain basic knowledge points: Cross-domain knowledge points Four ways for iframe to achieve cross-domain: Four ways for iframe to achieve cross-domain Note: The virtual host used in this article is also configured in the iframe above. Table of Contents JSONP cross domain Introduction to JSONP Cross-domain experiments: WebSocket cross domain Introduction to websockets Cross-domain experiments […]

Database integrity – entity integrity, referential integrity, attribute constraint naming clauses, domains

Article directory Database integrity 1. Entity integrity 1. Define entity integrity 2. Entity integrity check and breach handling 2. Referential integrity 1. Define referential integrity 2. Reference integrity check and default conditions 3. Constraints on attributes 1. Definition of constraints on attributes 2. Inspection of constraints on attributes and handling of breaches 4. Integrity constraint […]

[Open Source] Design and implementation of domestic waste recycling system based on Vue.js

Directory 1. Abstract 1.1 Project introduction 1.2 Project detailed screen recording 2. Research content 3. Interface display 3.1 Log in and register 3.2 Resource Type & Resource Category Module 3.3 Recycling mechanism module 3.4 Resource purchase/sale/transaction order module 3.5 Customer service consultation module 4. Disclaimer 1. Summary 1.1 Project Introduction The domestic waste recycling system […]

Rand random number-guessing number game implementation

Game Requirements: The computer automatically generates random numbers from 1 to 100 The player guesses the number. During the process of guessing the number, feedback is given as to whether the number is too big or too small according to the size of the guessed number. Until the correct answer is guessed, the game ends. […]