飞链云

MySQL update lock table timeout Lock wait timeout exceeded

Background recently in order to do a certain function of examination and approval, after nailing approved orders update review state, and then add a warehouse, and update the inventory status: / / order for examination and approval by @ Transactional...

2022-12-01 | InfoQ | 664 views

Detailed HashMap source code analysis (below)

The above introduces HashMap as a whole and introduces the data structure, main attribute fields, index subscripts for obtaining arrays, and several construction methods.This article focuses on the main methods of adding, searching, and expanding ele...

2022-12-01 | InfoQ | 424 views

SpringBoot quickly integrates general Mapper

Foreword For back-end business development, each table needs to use common methods such as adding, deleting, modifying and checking of single tables, and configuring the general Mapper can greatly facilitate the use of adding, deleting, modifying and...

2022-12-01 | InfoQ | 740 views

Java assigns values ​​through reflection annotations

Some time ago, the leader assigned a statistical summary of sales area data. The solution used reflection to obtain annotations, and obtained attributes or set field attributes through annotations.Problem Description Query the list of companies, whic...

2022-12-01 | InfoQ | 775 views

Detailed MySQL isolation level

A transaction has ACID characteristics, that is (Atomicity, Consistency, Isolation, Durability, that is, atomicity, consistency, isolation, and durability). This article mainly explains the Isolation, which is the isolation of transactions.Overview T...

2022-12-01 | InfoQ | 527 views

Java scans the classes under the specified package

Key idea String f = Thread.currentThread .getContextClassLoader .getResource packName.replace “.”, “/” .getFile ; The key point is the above line of code, which is to obtain the address of the compiled root directory.For example, in eclipse, the addr...

2022-12-01 | orange_? | 288 views

SpringBoot integrates RabbitMQ to realize six working modes

RabbitMQ mainly has six working modes. This article integrates SpringBoot to introduce the realization of the working modes.Premise Concept Producer message producer or sender, use P to indicate: null queue message is sent from the producer to the co...

2022-12-01 | InfoQ | 561 views

Centos7 installs Nginx tutorial, installs http and https in one step

Nginx is a lightweight web server with load balancing and reverse proxy features.Installation preparation Some modules of nginx need to depend on the lib library, so install the lib library first, and execute the following command: [email protected] loc...

2022-12-01 | InfoQ | 595 views

[Graphic Algorithm Data Structure] Search and Backtracking Algorithms + Java Code Implementation

Article catalog 1. Path in the matrix 3 2. The range of motion of the robot 35 3. The substructure of the tree 54 4. The mirror image of the binary tree 73 5. Symmetrical binary tree 90 6. Printing the binary tree from top to bottom I I 109 7. From t...

2022-12-01 | WSKH0929 | 512 views

Redis Best Practices (Part 1)

Introduction Although redis is a very good NoSQL database, more importantly, as users, we should learn how to use it better in different scenarios and maximize its value.It can be optimized mainly from these four aspects: Redis key-value design, batc...

2022-12-01 | Erudite Valley Wild Architect | 770 views

Rounding a HashMap source code parsing (on)

jdk version: 1.8 Data structure: The bottom layer of HashMap is mainly implemented based on array + linked list/red-black tree. The advantage of array is the query block. HashMap obtains the subscript of the array by calculating the hash code to quer...

2022-12-01 | InfoQ | 515 views

Adjacency Matrix of graph data structure (Python version)

For a data structure such as a graph, we implement the Python version of the dictionary of the graph data structure 41896770/article/details/128125901 'Python version of the dictionary of the graph data structure' There is an example that can show ho...

2022-12-01 | Yin Ke Guangqian | 840 views

Adjacency List of Adjacency List of Graph Data Structure (Python Edition)

I have learned the data structure of two kinds of graphs before, and those who are interested can refer to: Dictionary of graph data structure implements Python version icon default.png?t=M85B editor html/release2.2.0/ckeditor/plugins/CsdnLink/icons/...

2022-12-01 | Yin Ke Guangqian | 735 views

Spring and Summer Essays (31)

Australia is entering summer today, and it will continue to rain in the next 10 days. The high temperature will not exceed 25 degrees, and the low temperature will be around 15 degrees. It will be cool in early spring sooner or later.Browsing the win...

2022-12-01 | photography | 214 views

JavaScript Spreadsheet: DataGridXL 2.0.12

JavaScript Spreadsheets: DataGridXL DataGridXL provides a Microsoft Excel-like experience for web applications.DataGridXL is a high-performance data grid written in JavaScript ES6 with performance and usability in mind.DataGridXL is like Microsoft Ex...

2022-12-01 | john_dwh | 711 views

Dictionary implementation of graph data structure (Python version)

Graph is an abstract data structure, such as the interaction between accounts in social networks, route planning during driving, etc. These can be realized using graphs, such as how many routes are there from city A to city D, and then choose the sho...

2022-12-01 | Yin Ke Guangqian | 307 views

Mysql--Review Feed

1. Write it first, forget it when you learn it, and forget it if you don’t need it. I’m too forgetful. I’m here to record it for review and punch in Mysql.InnoDB records to memory, restarting the database and OPTIMIZE operations will be lost.1. The H...

2022-12-01 | Wang Defa! | 307 views

What are the types and characteristics of HTTP DDOS attacks?

https://img blog.csdnimg.cn/7f6511914ae04db191710ce76883cfbe.png 1. Attack type 1. HTTP floods This attack type is divided into two forms: HTTP GET request floods and HTTP POST request floods. The first type of attacker constructs HTTP GET requestsA ...

2022-12-01 | Zhongyun Era-Defense can be tested-Xiao Yu | 281 views

Docker network mode

1. Docker network 1 Docker network implementation principle docker uses linux bridge to virtualize a docker container bridge (docker0) on the host machine. When docker starts a container, it will assign an IP address to the container according to the...

2022-12-01 | I bloom in the killing | 617 views

The "Post-00s" are all together, and the World Cup is showing a "Youth Storm"

Undoubtedly, Argentine forward Messi and Portuguese Ronaldo have a large number of fans around the world, and they are still dazzling superstars in world football. However, more and more topics about the two superstars who cherish each other focus on...

2022-12-01 | Dayang.com-Sports | 483 views