Programming VIP

How to understand "heap" Heap sorting is an in-situ sorting algorithm with time complexity of O(nlogn) There are two characteristics of the heap: A complete binary treeEach node in the heap must be greater than or equal to (or less than or equal to) the value of its left and right child nodes; The heap whose value of each node is g ...

🏠: Blog home page: Incoming bogey 📕: Today's article: [Java] IO stream Foundation 💝: I hope my interpretation of the source code can help you 🎈 🌱: Boji is still trying to learn JavaSE. If you have any questions or omissions, please give me more advice 🙏 ☀️: On the way of self-study and growth, thank you for your company! No hurry ， ...

1, Interface 1.1 what is the interface First of all, explain the rookie tutorial, which is very professional Interface (English: Interface), an abstract type in JAVA programming language, is a collection of abstract methods. Interfaces are usually declared as interfaces. A class inherits the abstract methods of the interface by inheritin ...

What is the transaction propagation mechanism The propagation mechanism of transactions, as the name suggests, is how to propagate transactions between multiple transaction methods. For example, method A is A transactional method. Method B is called when method A executes. Whether method B has A transaction or not and whether it needs A tr ...

As we all know, the JVM's garbage removal algorithm is a copy removal algorithm used in the young generation, which is why the young generation is divided into two memory spaces of the same size: S0 and S1. When S0 is full, copy it to S1, and then empty S0. Of course, GC will tidy up the memory and make it continuous. What other common software ...

The start of the container is mainly to create the container, initialize the container, read the spring configuration file, generate the BeanDefinition, and create the bean instance through reflection according to the BeanDefinition. 1 webApp start loading The webApp startup process is mainly to load web xml web. The loading of XML will l ...

preface Java 8 provides many new features, but many friends don't pay attention to it and still use the old writing method. Recently, I read a lot of the source code of the open source framework and found that many API s of Java 8 have been used frequently. Taking the Nacos framework as an example, there are already typical Optional use cases ...

catalogue 1. add dependency 2. Add the configuration file resources \ config \ swagger properties 3. Write Swagger3Config configuration class 4. Write the Ctronller class 5. Start access address: 6. Swagger3 common notes 1. Add dependency <!-- introduce swagger3 package --> <dependency> <groupId>io.springfox< ...

1, Introduction to Apache POI Excel processing is often designed in development, such as exporting excel and importing excel into the database. A few years ago, there were two frameworks commonly used to operate excel, one is apache poi and the other is Java Excel. However, now there are EasyPoi and Alibaba open source EasyExcel, which wil ...

1, Explain In order to continuously update information and manage the ledger (write transactions, query, etc.), the blockchain network has introduced smart contracts to access and control the ledger; Smart contract is called chain code in Fabric, which is the business logic of blockchain application. This article shares how to use the Java ...