Programmer Group

Preface I have written a fan-shaped map drawing article in openlayers 4 before, but because it is written by encapsulating a layer of js code, many beginners seem to be a bit laborious, so this article rewrites a fan-shaped map drawing article, which is written directly based on the latest version of openlayers 6, in the form of pure html + ...

Take a look at the locks CountDownLatch and CyclicBarrier in Java Preface Basic introduction Use and difference Core source code analysis summary Preface Several articles have been written in Java JUC package. First of all, I spent 5 articles on AQS from the perspective of source code analysis. Why do I spend 5 articles on AQS? It's because ...

Introduction to Join Join is a very important operation in SQL statements. The common Join operations are as follows: mysql officially only provides an inner connection, a left outer connection, and a right outer connection.Other connections can also be made in some ways. Data preparation a. Create two tables create table `person` ( ...

1, List generation: the list can be generated dynamically instead of using fixed values to assign values to the list, so the program will be more flexible def test(i): # Even number if i % 2 == 0: return i # Ordinary generative list1 = [i * 2 for i in range(10)] print(list1) # Select values through a function list1 = [test(i) ...

Article directory 1, Problems and Solutions 2, Implementation principle of NestedScrollingParent2LayoutImpl3 2.1 let's review the nested sliding mechanism. 2.2 take a look at nested Scrollview 2.3 implementation principle of nestedscrollingparent2layoutimpl3 I wrote one before Nested slide &nd ...

You can pay attention to the author's account and the Java notebook from scratch. You can also go to the author's blog Garden to learn from the catalog. This film will be based on the black horse programmer job class video for learning and data sharing, and take notes and their own views. Welcome to study and discuss together. [learn Java note ...

HPA is the implementation of horizontal scaling in k8s. There are many ideas that can be used for reference, such as delay queue, time series window, change event mechanism, stability consideration and other key mechanisms. Let's learn the key implementation of the big guys together 1. Basic concepts As the implementation of general horizontal ...

demand The demand is like this: for example, background statistics show a relatively large total amount, such as 90,000,000, or more than 900 million. Need to show on the page again: xxxxbillion xxx10,000 XXX yuan, Amount value for statistics: If it's a billion then it's xxx10,000 XXX yuan, If it's 0 yuan, it's XXXX billion xxx million If it i ...

Today we share with you the well-known LRU algorithm. The first lecture consists of four sections. Overview of LRU LRU usage LRU implementation Overview of Redis Near LRU Part I: Overview of LRU LRU is an abbreviation for Least Recently Used, translated as least recently used.Its rationale is that "recently used data will remain in use f ...

1, background a. Sogou has also released its own AI API, including identity card ocr, business card ocr, text translation and other APIs, with average accuracy in the initial test. b. Based on Python 3. c. It also has its own signature to generate this piece. With the foundation of goose factory, it is relatively simple to write. d. However ...