Programmer Think

catalogue 1, Abstract class 1. Concept 2. Grammar rules 3. Some precautions 4. Role of abstract classes 2, Interface 1. Elaboration 2. Grammar rules 3. Some writing standards 4. Implement multiple interfaces 5. Inheritance between interfaces 6. Interface usage examples 7.Clonable interface and deep copy 8. Differences between inte ...

1.caffeine features Caffeine uses ConcurrentHashMap internally, provides a variety of cache elimination mechanisms (according to time, weight, quantity, etc.), and supports elimination notification. Moreover, caffeine has high cache performance on the premise of ensuring thread safety, which is known as the king of cache 1.1 official performa ...

Object class Object is the top-level superclass of all classes. There are two methods that are often overridden by subclasses: toString() and equals() package object; /** * Object Is the top superclass of all classes There are several methods that are often overridden by subclasses, including toString and equals */ public class Demo { ...

Annotation programming 01 what is annotation programming :::info It refers to adding specific annotations to classes or methods to complete the development of specific functionsThe use of annotations is convenient for development, the code is concise, and the development speed is greatly provided ::: 02 role of annotations :::success ...

generic paradigm Why use generics: Early Object types can accept any Object type, but in practical use, there will be the problem of type conversion. This hidden danger exists, so Java provides generics to solve this security problem What is generics: ● generic, i.e. "parameterized type". When referring to parameters, the most fam ...

background We have a regular task in a single project, which will query and calculate the scores and rankings of different users from each business table every other hour. It is realized by Quartz; This encountered a problem in the later horizontal expansion to multi instance cluster deployment: the scheduled task is repeatedly executed in mul ...

Kotlin grammar manual (I) When using kotlin, because the mastery is not reliable enough, it is still a habit of Java programming, which wastes the language features, convenience and indirectness provided by kotlin. When reading some Android open source libraries, it is difficult to read because many of them are written by kotlin syntax, and it ...

Configuration version 1. Create a new Moudle, springmvc-02-hello, and add web support! 2. Make sure the dependency of spring MVC is imported! 3. Configure web XML, register DispatcherServlet <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema ...

Hit in front: part of the picture is cut from the horse soldier teacher servlet and jsp Lecture notes. Video link: https://www.bilibili.com/video/BV1cV411H7RY?p=1 **Operation principle of tomcat: * Interactive process: The client sends a request to the server. tomcat request receives the request and presents it to the service request object. ...

I am a graduate of 21 years with one year's work experience. My resume and professional skills are as follows. Now I review and prepare for the interview according to my resume and knowledge. Record date: January 15, 2022 Most knowledge points are only briefly introduced, and the specific contents are reviewed in detail according to the re ...