0, reflection technology Reflection technology is an important part of the Java ecosystem and has been widely used in Spring and other frameworks. With reflection technology, we can: construct an object of any class, Know the class to which any object belongs, Know all member variables and methods in any class, Call properties and methods […]
Tag: ria
Keep in mind MyBatis’s first-level, second-level cache and serialization issues
A cache is a space in memory that is usually used to improve query efficiency. MyBatis supports two cache technologies: first-level cache and second-level cache. The first-level cache is enabled by default, and the second-level cache is disabled by default. Level 1 cache: Level 1 cache is enabled by default It is a cache based […]
Linux– Process priority and environment variables
Directory process priority basic concept How to check priority PRI and NI NI value setting range How to modify the NI value Modification method 1: Modify the priority through the top command Modification method 2: Modify the priority through the renice command Four important concepts of process environment variable basic concept Common Environment Variables View […]
Class variables, class methods, code blocks, abstract classes, interfaces, and inner classes
After learning about encapsulation, inheritance, and polymorphism in object-oriented programming, I recently came into contact with several new knowledge points. Sort it out here, help yourself to review, and also record my learning experience. 1. Class variables and class methods Instance objects of the same class only share a template prototype, and do not share […]
Shell variable functions
What is a variable? ? It should be easy to understand, y=ax + b, y is a variable, ax + b is the content of the variable, the left side of the equal sign is an unknown number, and the right side of the equal sign is a known number. Simply put, a variable is […]
Implementation of embedded linux output redirection (serial port telnet mutual switching)
For scenarios such as batch on-hook testing of equipment, remote customer complaint handling, etc., it is still very practical to add a serial port redirection to the telnet port printing function. For this reason, it is packaged into an independent file. Not much to say, just copy it into the project and use it directly. […]
K_A22_005 STM32-based drive 360-degree encoder module serial port and digital tube dual display
K_A22_005 is based on STM32 driving 360-degree encoder module, serial port and digital tube dual display All resource navigation 1. Resource description 2. Basic parameters Pin Description 3. Driver instructions Corresponding program: Fourth, part of the code description 1. Wiring pin definition STM32F103C8T6 + 360 degree encoder module 5. Basic knowledge learning and related data […]
05-STM32F1 – Serial communication 2-I2C (1), I2C configuration
05-STM32F1 – Serial communication 2-I2C (1), I2C configuration Physical layer It is a bus that supports devices. A “bus” refers to a signal line shared by multiple devices. In one I2C communication bus, multiple I2C communication devices can be connected to support multiple communication masters and multiple communication slaves. An I2C bus uses only two […]
16 lines of python code to get sound effect material
Life is short, I use python Sound asset: Source code information e-book: Click here to jump to the business card at the end of the article Required environment Development environment Python environment Pycharm editor Module requests re Process explanation First, we open the URL and right-click to select inspect select network, Refresh the page and […]
FPGA – serial transceiver
The three commonly used low-speed serial communication are UART, SPI, and IIC. Here FPGA is used to realize UART communication. UART communication has only two wires, one is to send data tx, and the other is to receive data rx. PC and PFGA realize data communication through two wires. Complete the transceiver design of the […]