Programmer Think

scene The company has a piece of business that needs to run the timer business to process data. Background uses springBoot to develop, springBoot integration timer task is very simple, use Scheduled is configured to use cron, and a business is executed 45 minutes per hour, because the background is cluster deployed, and the front end is respon ...

Hello, I'm a little circle who loves to learn programming. Today I'll talk about the if/elif/else statement code import time as t a = 0 while a < 1: x = input('Please enter a number (1-9)\n') y = ['1', '2', '3', '4', '5', '6', '7', '8', '9'] if x in y: print('The input is correct!') t.sleep(5) a=a + 1 ...

overview There are two very famous improvements in java8, one is Lambda expression and the other is Stream. Stream is a stream. Its main function is to search and filter Collection data. It is similar to SQL database operation. The difference between stream and Collection is that Collection is only responsible for storing data, not for other ...

Questions In the process of calculating the percentage of statistical tables, because of the accuracy problem, 99.97% or 100.1% of the calculated results are not equal to 100%, the original scheme generally uses the last value equal to 1 minus the percentage to complete the calculation, but there are disadvantages in this way. Abnormal data of ...

Since our Web application is running in tomcat, the request must arrive at Tomcat first. Tomcat actually handles the request as follows. First, provide Socket service The start of Tomcat must be Socket service, but it only supports HTTP protocol! In fact, we can expand our thinking here. Since Tomcat is based on Socket, what about BIO or NIO ...

A recent scenario in business is that if a user has not paid for 30 minutes after placing an order in a store, the order needs to be disposed of, either deleted or marked as invalid. Why? 1. Inventory, the user will lock an inventory after placing an order. If the user does not pay, it will occupy the inventory and affect other users'purchase. ...

brief introduction The new feature of switch has a long history. It was introduced as a preview function as early as JDK 12, and finally became an official version of the function in JDK 14: JEP 361: Switch Expressions (Standard). In fact, there are two new functions of switch, one is that case can be linked, the other is that switch can bring ...

Today, I installed the docker environment for my colleagues in the R & D department on the domestic winning Kirin 7.4 operating system. Because of its special environment, I couldn't use the Internet repo source, so I only used the rpm package for the installation. Because it is the first time to use the rpm package for the installation of ...

Introduction to producer consumer model 1. Why the producer consumer model is needed Producer refers to the task of production data, and consumer refers to the task of consumption data. When the producer's production capacity is far greater than the consumer's consumption capacity, the producer needs to wait for the consumer to consume before c ...

order This paper mainly studies the bootstrap controller of maxwell BootstrapController maxwell-1.25.1/src/main/java/com/zendesk/maxwell/bootstrap/BootstrapController.java public class BootstrapController extends RunLoopProcess { static final Logger LOGGER = LoggerFactory.getLogger(BootstrapController.class); private final long MAX_TX_ELEMEN ...