Programmer Group

Open Closed Principle (OCP): when the application requirements change, the functions of the module can be extended to meet the new requirements without modifying the source code or binary code of the software entity.Liskov Substitution Principle (LSP): subclasses can extend the functions of the parent class, but cannot change the original funct ...

First of all, some rules I usually use, and then some useful rules and usage scenes.Download directory Tag the latest downloaded file: each downloaded file is tagged as the recently downloaded file, so that you can directly view the latest downloaded file through the tag in the FinderLabel the files that have not been processed for more than ...

Used to define button components in the gui interface   tkinter.Button ](Parent component for storage,attribute parameter...) Component 1 button It has the following properties:  EG1: from tkinter import * root = Tk() root.title("Window title") # Whether the window size can be changed, width and height. True indicates that it can b ...

1, Message queue 1.1 related concepts of MQ 1.1.1 what is MQ MQ(message queue), in its literal sense, is essentially a queue. FIFO is first in, first out, but the contents stored in the queue are messages. It is also a cross process communication mechanism for upstream and downstream message delivery. In the Internet architecture, MQ is ...

1, Service Introduction Service is one of the four components in the android system (Activity, service, BroadcastReceiver and ContentProvider). It is similar to the level of Activity, but it cannot run by itself, can only run in the background, and can interact with other components. Service can be used in many applications. For example, when p ...

prefaceMainstream distributed locks are generally implemented in three ways:Database optimistic lockRedis based distributed lockDistributed lock based on ZooKeeperPreviously, I wrote on my blog about the specific scheme for mysql and redis to implement distributed locks:[ https://www.cnblogs.com/wang-meng/p/10226618.html](https://links.jianshu. ...

1, I2C bus protocol 1. What is the I2C protocol I2C communication protocol (Inter Integrated Circuit) is developed by Phiilps company. Due to its few pins, simple hardware implementation and strong scalability, it does not need external transceiver equipment of USART, CAN and other communication protocols. Now it is widely used in the com ...

Environmental preparation Docker and docker compose installation( https://docs.docker.com/compose/install/)#docker installation curl -sSL https://get.daocloud.io/docker | sh #Docker compose installation curl -L \ https://get.daocloud.io/docker/compose/releases/download/1.23.2/docker-compose-`uname -s`-`uname -m` \ > /usr/local/bin/docker ...

When we do projects, we often need to integrate and filter the data, and judge after using the for loop every time. I believe you must be tired. Now the Lamda expression newly exited by Java 8 and Steam API can perfectly process the data and complete the function of shuttling between the data. Stream means stream, which is slightly differen ...

GUI-AWT event handling The introduction of event handling mechanism is to respond to the user's behavior. Previously, after creating the Frame window, click X, but it cannot be closed. Because in AWT, all events must be handled by a specific object (event listener), the Frame and component itself are just a framework and cannot respond. Loading ...