Internal class, basic type, packaging class, date class

Inner class and API, exception Inner class Access characteristics of internal classes Internal classes can directly access members of external classes, including private classes An object must be created for an external class to access members of an internal classThe definition location of the class inside the member In a class, a method is ...

Added by Phirus on Sun, 16 Jan 2022 07:27:32 +0200

java Servlet annotation implementation filter

java Servlet annotation implementation filter What I wrote earlier: This article is related to Token verification. Visitors can go and have a look at my article Implementation of Token of Servlet How to implement Servlet filter: 1. Configure in xml file 2. Add comments in the file header First, we should know what a filter is ...

Added by OopyBoo on Sun, 16 Jan 2022 06:03:18 +0200

How is Go Error nesting implemented?

Go Error's design philosophy is "Errors Are Values". How should this sentence be understood? It's difficult to translate. However, from the perspective of source code, it seems easier to understand the meaning behind it. The source code of Go Error is very simple, just a few lines: // src/builtin/builtin.go type error interface { ...

Added by emceej on Sun, 16 Jan 2022 04:54:33 +0200

JAVA Basics - encapsulated fields, inheritance and polymorphism

preface Three basic characteristics of object-oriented: encapsulation, inheritance and polymorphism. For more detailed concepts, see the blogger's article Three characteristics and five basic principles Tip: the following is the main content of this article. The following cases can be used for reference 1, Encapsulate field 1. Conce ...

Added by omarh2005 on Sun, 16 Jan 2022 02:44:24 +0200

Java learning day36_CSS

1 CSS Web page -- > people HTML -- > skeleton CSS -- > skin and flesh CSS refers to cascading style sheets (cascading style sheets), which are mainly used to set the text content (font, size, alignment, etc.) in HTML pages, the appearance of pictures (width and height, border style, margin, etc.) and the layout of layout, etc. CSS is ...

Added by The1PatO on Sun, 16 Jan 2022 02:36:16 +0200

2 variables and operators

1.1 define integer / long integer / single precision floating point... Variables int variable name = initial value; eg: int num = 10;//Define an integer variable System.out.println(num);//Output defined integer variables public class HelloWorld { public static void main (String [] args) { int a=10;//Defines a variable of type int System.o ...

Added by ctiberg on Sun, 16 Jan 2022 00:16:55 +0200

Self labeled dataset training is based on pytorch3 7 yolov5 palm recognition model

Prepare dataset 1. Shooting Use the iphone 7 Plus continuous shooting function to take 1000 pictures of left and right hands in different light. 2. Picture renaming Mobile phone automatic naming is inconvenient to traverse, so it needs to be changed to 1 jpg,2.jpg. Run the following code. import os import re import sys path = r"D:data\im ...

Added by goochy808 on Sat, 15 Jan 2022 21:56:50 +0200

[ThinkPHP6.x framework] (11) association model of database

For association methods, the system provides 9 schemes, as follows: In the above example, we use the one-to-one association model, which also has relative reverse association; An example is given below: class Profile extends Model { public function user() { return $this->belongsTo(User::class); } } $profile = ProfileModel ...

Added by 10legit10quit on Sat, 15 Jan 2022 20:59:42 +0200

JVM drill down - drill down on java references

1. Reference in Java Reference is the bridge between heap and stack in java. If you want to access objects in the heap, you must access them through reference (except for 8 basic data types) In garbage collection, if an object is still referenced by GcRoots, it will not be recycled (strong reference). This is not absolute. It is mainly determi ...

Added by Aurasia on Sat, 15 Jan 2022 20:45:57 +0200

Date event class & exception

1. Time and date 1.1 Date class Time origin in computer January 1, 1970 00:00:00 Time conversion unit 1 second = 1000 milliseconds Overview of Date class Date represents a specific time, accurate to milliseconds Date class constructor Method nameexplainpublic Date()Allocate a Date object and initialize it so that it represents the time ...

Added by tdors on Sat, 15 Jan 2022 18:23:57 +0200