Programmer Group

  Original: https://www.cnblogs.com/dafanjoy/p/10904347.html First, let's look at the core variables ThreadPoolExecutor uses to represent the state of the thread pool   //Used to mark thread pool state (3 bits high), number of threads (29 bits low) //The default is RUNNING state with 0 threads private final AtomicInteger ctl = new Atomi ...

Summary CountDownLatch and CyclicBarrier are similar, and they are often compared. This time, the author tries to analyze the two classes respectively from the source point of view, and from the source point of view, see the differences between the two classes. CountDownLatch CountDownLatch is literally a counting tool class. In fact, this clas ...

[overview] There are at least three schemes to realize the identity authentication function based on face recognition: 1. Use the cloud services provided by major platforms, and call based on WEB API. API calls are charged per call. 2. Use SDK, embedded in the device. In this case, you need to develop your own hardware, and the SDK needs to be ...

Dom   One: Dom conceptIntroduction to Dom: The Document Object model is a complete set of methods for manipulating documents - Document - html, an object in a document, a top-level object in the dom, an object in window s, and arguably the best. Dom Node: All the steps that make up the entire html process are equivalent to all the labels, tex ...

Electronic clock is a common function on the Internet. When learning date object and timer function, it is a good choice to complete the production of an electronic clock. Before learning this tutorial, you need to have html and css skills, as well as a simple javascript foundation. Prepare an html element to place the clock. Create a new div e ...

Validator By:Mirror Wang Yuyang Verifier definition For the use of verifier, it must be defined; the system provides a command to directly produce a verifier class: php think make:validate User Generate a validate folder under the automatic re application directory and generate the User.php class namespace app\validate; use think\Validate ...

Title: There are n * k boards, each bucket is composed of K boards, and the capacity of each bucket is defined as the length of the shortest board. The capacity of any two wooden barrels v1, v2 meets the requirement of | v1-v2 | < D. Ask the maximum sum of N buckets, or explain that it is impossible to make such n buckets. Ideas: greedy ...

A small demand: When applying for software copyright, you need to submit a page of 50 lines, a total of 60 pages of source code. However, the designed project is saved in a multi-level directory and does not want to be copied one by one, so we get all the files in the directory through python and os modules, re regularize and filter the inval ...

Write on top 3.8 added several interesting features, optimized the module part of ECMAScript, #use of private fields instead of less stringent privates, and so on. 1. Import and export methods for type restrictions (Type-Only Imports and Export) TypeScript 3.8 adds a new syntax for type-only import and export. import type { SomeThing } f ...

SpringBoot has a built-in Hibernate Validator as the checking framework, so as long as we have integrated SpringBoot, we can use Hibernate Validator to complete parameter checking. Common Notes @Null: The commented property must be null; @NotNull: The commented property cannot be null; @AssertTrue: The commented property must be true; @AssertF ...