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1, Interface idempotency Interface idempotency means that the results of one request or multiple requests initiated by the user for the same operation are consistent, and there will be no side effects due to multiple clicks. The simplest example is payment. The user pays after purchasing goods, and the payment is deducted successfully. However ...

The object of Spring Security authentication and authorization is the user. The user mentioned here can be defined in the configuration file, stored in the database table, or automatically created by Spring Security (Spring Security will automatically create the user when there is no user or user source related configuration), Spring Security u ...

catalogue 01. What is the method? 02. Definition of method 03. Overload of method 04. Variable parameters 05. Recursion 01. What is the method? A Java method is a collection of statements that together perform a function. Method is an ordered combination of steps to solve a class of problemsMethod is contained in a class or objectMet ...

1, Code optimization principle (collated from) https://mp.weixin.qq.com/s/zBjfGihZYY6XcVdGkyQfww ) Before introducing the specific optimization rules, summarize three basic principles. 1. Don't optimize too early The premise of code optimization is that the code can work normally. Always remember that it's much easier to make the right prog ...

The class parameter here is the interface type of the extension point, and each loader needs to bind an extension point type. The loader is then fetched from the cache first, and a loader is initialized and cached before being fetched. When initializing a private constructor, we need to be aware of the objectFactory variable, which is probably ...

What are the built-in objects of jsp? What are the functions? What are the methods? How to use JavaBean s in JSP? Common instructions for JSP Four ranges of jsp? jsp scope from large to small What are the functions of filters? Filter usage? (uniformly encode the requests of the client and authenticate the client) How to realize the requ ...

lambda expression introduction The lambda expression introduced by java 8 simplifies our code by replacing anonymous internal classes, which are essentially anonymous classes. Simple use of lambda expressions Here's how we implement an interface using an anonymous internal class: public class Main { public static void main(String[] ...

Operators and Expressions Operator Classification: Arithmetic operatorShift operatorsBitwise operatorsAssignment operatorunary operatorRelational OperatorsLogical OperatorConditional Operatorcomma expressionThe structure members of the following table references, function calls Arithmetic operator + - * / % All but%can be used for operat ...

catalogue 1. Inheritance overview 2. Advantages and disadvantages of inheritance 2.1 benefits of inheritance 2.2 disadvantages of inheritance 3. Access characteristics of variables in inheritance 4. super keyword 5. Access characteristics of construction methods in inheritance 6. Access characteristics of member methods in inheritance ...

File operation The data generated when the program runs belongs to temporary data. Once the program is run, these temporary data will be released. At this time, we can persist the data through files. File operations in C + + need to include header files < fstream There are two types of files: Text file: the file is stored in the comp ...