Articles
android

Various ways, principles and problems encountered in uploading Spring Boot files from building development scaffolding

Article Directory File Upload Overview commons-fileupload Servlet 3.0 Single file upload Multiple file upload File upload with other parameters Elegant back-end implementation Multiple (file + parameters) upload Solution 1: Upload file Base64 Option 2: upload file url File upload principle Problems encountered Spring Boot upload file size limit The upload file is too large to be blocked Custom tomcat working directory Uploading files using swagger does not work File Upload Overview Spring suppor

... Brandon
schedule 11 min read
android

[Design mode] Flyweight mode, the guiding ideology of pool technology!

This is the 29th day that I participated in the Wenwen Challenge. For details of the event, please view: Wenwen Challenge Design pattern catalog What is Flyweight concept Flyweight Pattern is a structural pattern, which is mainly used to reduce the performance consumption of object creation and destruction to reduce memory usage . Object-oriented languages can bring a certain degree of flexibility and scalability to our development, and are more in line with people's way of thinking, but this wi

... Abraham
schedule 12 min read
android

RxJava2-Transformation operator study notes

This study note mainly refers to Android RxJava: Detailed Explanation of Transformation Operators in Graphic and Text This blog, the original blog is full of graphics and texts, thanks to the original author for sharing, you can click on the blue font above or click here to view the content of the original blog. This article learns The pictures in the notes are all from the pictures of the original blog. Thanks again to the blogger for sharing. This study note mainly recordsmap(),flatMap(),conca

... Hudson
schedule 13 min read
android

I resigned from Huawei outsourcing two years ago, but now that the start-up company goes bankrupt, what should I do at the age of 36?

Dream of Dachang On my 36th birthday, I lost my job. The year before last, I resigned from Huawei outsourcing and went to a startup company in Shenzhen. The company's main project is loan app development. I wanted to last for two years, but in less than a year, the state controlled finance, the capital chain was broken, and the company went bankrupt. I remember when I went to a startup company, my friend felt that this option was risky, and outsourcing was more stable, "basically the same as a p

... Alejandro
schedule 15 min read
android

RecycleView caching principle

problem First, let's take a look at why the adapter in RecycleView (mainly adapter mode, observer mode adapter notification update UI) is an adapter mode! Adapter mode The most commonly used when using recycleView is the adapter, also known as the adapter mode, then let's see which ones are available Class adapter The class adapter is integrated with the adapter, which is the inheritance relationship, and implements the target method, rewriting the method of calling the adapter in the target met

... Wesley
schedule 26 min read
coder_life

Simple http server based on the epoll model

blog.csdn.net/baudgg1992/...  The epoll model mainly has two working modes: horizontal trigger (LT) and edge trigger (ET). This article is mainly about edge trigger. The epoll multi-threaded model implemented in this article is mainly that the main thread waits for the event to be triggered, and then puts the relevant event into the queue, and the thread pool takes out the data processing event from the queue. The following is the specific implementation:     Copy code #include &l

... Justin
schedule 7 min read
coder_life

My personal understanding of mqtt protocol and emqttd open source project (13)-Hook uses and connects to Kafka to send messages, and uses brod library

1. Work environment preparation The erlang kafka client library uses brod, github.com/klarna/brod emq uses the v2.3.5 version, github.com/emqtt/emq-r... Kafka operating environment preparation, blog.csdn.net/libaineu200... We implement it in the form of a plug-in, and my plug-in path is /home/firecat/Prj/emq2.0/emq-relx-2.3.5/deps Copy a copy of emq_plugin_template and rename it to emq_plugin_kafka_brod. Note that the relevant configuration files and source files must be renamed. Enter the direc

... Thomas
schedule 9 min read
coder_life

C++ basic knowledge points finishing

Basic grammar 1. The role of the static keyword 1. Global static variables Global variables with static keyword added can only be used in this file. It is stored in the static storage area and exists during the entire program operation. 2. The scope of the local static variable is still the local scope. However, after leaving the scope, it is not destroyed, but stored in the program and cannot be accessed unless the function is called again. 3. Static function can only be used in the file where

... Jack
schedule 15 min read
coder_life

Summary of 2015 Internet School Recruitment-Along the way

Article source: blog.csdn.net/ns_code/art... Write in front     After finishing my internship at Baidu, it s time to write a summary of the school recruitment. I have been in the open source community for a long time, and I feel more and more positive energy from other people s study, job hunting, and work experience. In line with the principle of earning RP, I pass it on to the younger students, especially those from non-prestigious schools. Point positive energy, because bloggers are

... Hudson
schedule 29 min read
coder_life

After four years of graduation, how did I embark on the road of programming! Mid-2021 Summary

Inscription There are many feelings, and it has been 4 years since graduation. Thinking of learning programming in college, it feels very meaningful. Let me record and review it here. I hope I have not changed my original intention and move forward courageously Current status and past 20210706 At present, I am doing software development in a company in Tianjin. I mainly do C# desktop development, and sometimes I write some Android, but the main skills are still C# and ASP.NET. Isn t it surprisin

... Leonardo
schedule 23 min read
dev_tools

Java study notes [continuous update]

A simple java program is as follows: class Sakura { public static void main(String[] arges) { system.out.println("Hello World"); system.out.print("hahaha"); } } 1. The appearance of the main function can ensure the independent operation of a class 2. In the java program, the difference between pirnt and println is whether to print a carriage return and line feed after println outputs a line, but print does not! Let's take the suffix 123.java as an example to analyze the java source file: The add

... Summer
schedule 32 min read
dev_tools

Big program design

Due to improper decision-making last semester, I made a very simple gomoku game with the lql boss, which led to tears in the game.in, So this semester one person has a 400-line information management system for college teachers and students. Design flow chart: Screenshot of part of the running interface: code show as below: # include <map> # include <set> # include <list> # include <queue> # include <deque> # include <cmath> # include <stack> # include

... Cameron
schedule 12 min read
dev_tools

12 ( )

pay.weixin.qq.com/wiki/doc/ap 1. 2. API 3. code_url 4. code_url 5. 6. 7. 8. 9. 10. 11. API 12. 1. appid APP 2. mch_id ( partner) 3. partnerkey 4. sign: , , 1. <!--httpclient --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> </dependency> <!-- SDK--> <dependency> <groupId>com.github.wxpay</groupId> <artifactId>wxpay-sdk</artifactId> <version>0.0.3</version> &l

... Dominic
schedule 11 min read
dev_tools

Realization of smooth database expansion for 100 billion-level data smooth expansion

1. Deployment architecture after expansion The previous dual-master and two nodes are expanded to two pairs of dual-masters, with a total of four nodes: 2. New database VIP Increase the virtual IP configuration on the Server2 node: Modify /etc/keepalived/keepalived.conf and add: ... {VI_2 vrrp_instance #vrrp instance defines State the BACKUP #lvs state mode, the main representative of the MASTER, on behalf of the BACKUP backup node interface ens33 # access the external network adapter binding vi

... Riley
schedule 13 min read
dev_tools

Seek and then move: Interpretation of the mystery of line number estimation and path generation in the generation of data warehouse plans

Anything must be planned and deployed, and prepared, so as to be conducive to the success of this matter, and we must not act recklessly. Similarly, the GaussDB (DWS) query statement will be executed according to the predetermined plan. In the case of a given hardware environment, the execution speed depends on the quality of the plan. So how is the plan of a query statement formulated? This article will Interpret the mystery of line number estimation and path generation in plan generation for

... Daniel
schedule 35 min read
programming

3.4 HarmonyOS Image

3.4 HarmonyOS Image Image XML Image XML Component Image XML clip_alignment left ohos:clip_alignment="left"right ohos:clip_alignment="right"top ohos:clip_alignment="top"bottom ohos:clip_alignment="bottom"center ohos:clip_alignment="center"image_src Element color media/graphic ohos:image_src="#FFFFFFFF"ohos:image_src="$color:black"ohos:image_src="$media:warning"ohos:image_src="$graphic:graphic_src"scale_mode zoom_center Image ohos:scale_mode="center"zoom_start Image zoom_end Image stretch Image ce

... Luis
schedule 4 min read
programming

SpringBoot add, delete, modify and check

I just started learning SpringBoot recently and made a small project to practice my hands. Just to make a record to provide a reference for students who have never been in contact with SpringBoot. Super detailed! ! ! There is a directory structure! ! ! One, create a project Use IDEA to create a new springboot project, which can be generated using IDEA or on the official website. JDK: 1.8 Java: 8 Spring official website start.spring.io/ Add project dependencies Spring Web Mybatis Framework MySQL

... Liam
schedule 7 min read
programming

Bash tutorial mode extension

table of Contents   Introduction Wavy line expansion ? Character expansion * Character expansion Bracket expansion [start-end] extension Brace expansion {start..end} extension Variable expansion Subcommand expansion Arithmetic expansion Character class Points of Attention Quantifier shopt command Introduction After Shell receives the command entered by the user, it will split the user's input into tokens according to the space. Then, the Shell will expand the special characters in the lemma

... Levi
schedule 20 min read
programming

C language programming introductory training (two)

C language programming introductory training (two) Article Directory C language programming introductory training (two) Exercise 11: ASCII code Exercise 12: Date of Birth Input and Output Exercise 13: Input according to format and exchange output Exercise fourteen: character to ASCII value Exercise 15: Calculate the value of an expression Exercise 16: Calculate division with remainder Exercise 17: Kiki is arithmetic Exercise 18: The single digits of floating-point numbers Exercise 19: How many s

... Matthew
schedule 7 min read
programming

Summary of common methods of javascript array

Summary of data commonly used methods forEach traverse the array let arr = [ 15 , 26 , 23 , 10 , 9 , 6 , 78 , 21 , 24 , 10 , 9 ]; arr.forEach( ( item, index ) => { console .log( "The value is" + item, "The subscript is" + index); }); Value is 15 Subscript is 0 Value is 26 Subscript is 1 Value is 23 Subscript is 2 Value is 10 Subscript is 3 Value is 9 Subscript is 4 Value is 6 Subscript is 5 Value is 78 Subscript is 6 value is 21 subscripted 7 value 24 subscripted 8 value 10 subscripted 9 valu

... Mark
schedule 13 min read
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