Programmer Group

1, shiro internal structure 1. Components contained in shiro shiro mainly includes Authenticator, authorizer, session manager, encryption, remember me and cache manager 2. Introduction to components of shiro Subject: the subject, which can be understood as the user interacting with the application, contains all the information of the us ...

Behavior mode: Observer mode: Also known as: event subscriber, Listener, event subscriber, Listener, Observer intention The observer pattern is a behavioral design pattern that allows you to define a subscription mechanism, Multiple "watch" other objects of an object can be notified when an object event occurs. Core: the observed and ...

Ftrace and its functions brief introduction Ftrace is a tracker of the kernel, which helps developers to check the operation of the kernel, so as to better analyze performance problems. Ftrace can help us analyze kernel specific events, track dynamic kernel functions, call stacks and stack usage. It can also help us track delays, such as when i ...

spring framework integration quartz @Scheduled Spring context support has two annotations for Scheduled tasks under spring, @ enablescheduled and @ Scheduled, which are easy to use 1. Add enableschedule where spring can scan @SpringBootApplication @MapperScan("com.hsm.quartztask.mapper") @EnableScheduling public class QuartzTaskApplication { ...

Handling exceptions in Java is not an easy task. It is not only difficult for beginners to understand, even some experienced developers also need to spend a lot of time thinking about how to handle exceptions, including which exceptions need to be handled, how to handle and so on. This is also the reason why most development teams will make som ...

1, Foreword For the current front-end developers, FlatUI is certainly not new. In recent years, flat design has become more and more popular. Probably because the resolution of PC and mobile devices is getting higher and higher, flat design looks more pleasant, while the texture color produced by gradient color is not so kind as flat design. Fl ...

brief introduction Before JDK11, the HTTP function of java was very weak, only HttpURLConnection was provided for HTTP connection, and it was very complex to use. So we usually use the third-party HTTP client (Apache HttpComponents or OkHttp) to make HTTP requests. Everything has changed in JDK11. In the java.net.http package, the latest HttpCl ...

1. Why random verification code is needed Prevent malicious machine registration. The role of verification code: effectively prevent this problem from a specific registered user using a specific program brute force to try to login, in fact, verification code is the current way of many websites, using a relatively simple way to achieve this fun ...

install Oracle installation command pip install orator ##Easy to use Connection operation of database config = { 'mysql': { 'driver': 'mysql', 'host': 'localhost', 'database': 'test_one', 'user': 'root', 'password': '123456', 'prefix': ...

Recently, a data statistics system has been designed. There are hundreds of data statistics dimensions in the system, and the indicators of these data statistics may be adjusted at any time. If the API design of data statistics is implemented one by one based on Java coding, the workload is large and the maintenance cost is high. Finally, it is ...