SpringBoot scheduling tasks and common task expressions

1. Redis implements distributed lock principle and why distributed locks are needed. Before talking about distributed locks, it is necessary to explain why distributed locks are needed. The opposite of distributed locks is stand-alone locks. When we write multi-threaded programs, we avoid data problems caused by operating a shared variable at the same time. We usually use a lock to mutually exclude the shared variables to ensure the correctness of the shared variables. Its scope of use is in the same process. If there are multiple processes that need to operate a shared resource at the same time, how can they be mutually exclusive? Today's business applications are usually microservice architecture, which also means that one application will deploy multiple processes. If multiple processes need to modify the same row of records in MySQL, in order to avoid dirty data caused by out-of-order operations, distribution needs to be introduced at this time. The style is locked. Want to achieve points

Springboot reads the file, but cannot access the latest development after packaging it into a jar package. There is a situation where springboot cannot read the file after packaging it into a jar package. The reason is that after packaging, the virtual path of the file is invalid and can only be accessed through the stream. Read. The file is under resources publicvoidtest(){Listnames=newArrayList();InputStreamReaderread=null;try{ClassPathResourceresource=newClassPathResource("name.txt");Input

When Springboot+Mybatis-plus does not use SQL statements to perform multi-table adding operations, the problems I encountered are decomposed by simulating thinking in the test environment: Create a BrandDTO object with parameters to simulate passing parameters to the background. We all know that it is extremely difficult to perform multi-table operations in Mybatis-plus. If you do not use tools such as Mybatis-plus-join, you can only configure the corresponding Mapper.xml file and configure The smelly and long ResultMap, and then write the corresponding sql statement. Although this method seems cumbersome, it is highly flexible and allows us to

SpringBoot and SpringMVC are both commonly used frameworks in Java development, but there are some obvious differences between them. This article will explore the features and uses of these two frameworks and compare their differences. First, let's learn about SpringBoot. SpringBoot was developed by the Pivotal team to simplify the creation and deployment of applications based on the Spring framework. It provides a fast, lightweight way to build stand-alone, executable

1. Customize RedisTemplate1.1, RedisAPI default serialization mechanism. The API-based Redis cache implementation uses the RedisTemplate template for data caching operations. Here, open the RedisTemplate class and view the source code information of the class. publicclassRedisTemplateextendsRedisAccessorimplementsRedisOperations, BeanClassLoaderAware{//Declare key, Various serialization methods of value, the initial value is empty @NullableprivateRedisSe

In projects, some configuration information is often needed. This information may have different configurations in the test environment and the production environment, and may need to be modified later based on actual business conditions. We cannot hard-code these configurations in the code. It is best to write them in the configuration file. For example, you can write this information in the application.yml file. So, how to get or use this address in the code? There are 2 methods. Method 1: We can get the value corresponding to the key in the configuration file (application.yml) through the ${key} annotated with @Value. This method is suitable for situations where there are relatively few microservices. Method 2: In actual projects, When business is complicated, logic

By default, macOSSonoma hides all active windows when you click on your desktop wallpaper. This is convenient if you tend to have a bunch of files on your desktop that you need to access. However, if you find this behavior maddening, there is a way to turn it off. Apple's latest macOS Sonoma Mac operating system has a new option called "Click the wallpaper to show the desktop." Enabled by default, this option can be particularly useful if you tend to have multiple windows open and want to access files or folders on your desktop without having to minimize or move the windows. When you enable the feature and click on the desktop wallpaper, all open windows are temporarily swept aside, allowing direct access to the desktop. Once done, you can again

This article will write a detailed example to talk about the actual development of dubbo+nacos+Spring Boot. This article will not cover too much theoretical knowledge, but will write the simplest example to illustrate how dubbo can be integrated with nacos to quickly build a development environment.