Common java array usage

1. Assignment Two assignment methods Static initialization: define the contents of the array directly from the beginning Dynamic initialization: open up the space first, and then assign values later. You can not assign all values (at this time, the initial values are not assigned, such as 0 and null) // statement int[] ids; //1.1 s ...

Added by dmort on Wed, 29 Dec 2021 09:38:56 +0200

Small knowledge of Java se -- how to export and use the jar toolkit written by yourself

Article catalog The road to becoming a God is long and lonely. Today, I share a little knowledge about how to export and use the toolkit I wrote through the tool Eclipse into classes preface Tip: Here you can add the general contents to be recorded in this article: For example, with the continuous development of artificial intelligenc ...

Added by luv2sd on Sat, 25 Dec 2021 08:53:42 +0200

Learning Java multithreading is enough (good article is worth sharing!)

Multi thread learning 1. Multithreading_ concept Multithreading, in short, is multitasking. Inter method call: an ordinary method call is a closed path from where to where. Multithreading: opens up multiple paths. 2. Multithreading_ Inherit Thread There are three ways to create threads: (1) Inherit Thread(2) Implement Runnable interfac ...

Added by smilesmita on Tue, 21 Dec 2021 05:12:22 +0200

The end of Java concurrency series: thoroughly understand the working principle of java thread pool and want to enter BTAJ

//Use the thread pool to perform a task executor.execute(() -> { // Do something }); //Closing the thread pool will prevent the submission of new tasks, but it will not affect the submitted tasks executor.shutdown(); //Close the thread pool, prevent new task submission, and interrupt the currently running thread executor.showdownNow( ...

Added by Traveller29 on Sat, 18 Dec 2021 16:26:50 +0200

Java learning notes - Connection Pool

Connection pool When JDBC executes an SQL statement, most of the time is wasted on creating and closing connections, and the user experience is very poor Connection pooling can be used to manage connections, so connection pooling is a buffering technology used to manage connections. Working process of connection pool The role of connection ...

Added by WakeAngel on Fri, 17 Dec 2021 12:07:07 +0200

Spring source code debugging environment construction

1. Spring source code download address:         https://github.com/spring-projects/spring-framework , version 5.2 x 2. Install Gradle: Spring relies on Gradle build tools to manage package dependencies (1) Gradle download address: https://services.gradle.org/distributions/ or https://gradle.org/releases/ (2) Configure environment variabl ...

Added by kevin99 on Thu, 16 Dec 2021 11:22:32 +0200

File upload and download

1, File upload Dependent jar packages: comments-fileupload.jar comments-io.jar 1. Form attribute enctype = "multipart / form data" method = "post"; 2. Request code and response code settings; 3. 3 steps to parse request object Create factory class: FileItemFactory factory=DisFileItemFactory(); Create parser: servlet ...

Added by wit77 on Wed, 15 Dec 2021 05:51:59 +0200

Java basic custom control layer framework

Custom control layer framework core file The core file of the control layer framework is xml file, and almost all frameworks use xml file as configuration file. web. As the core file of Java Web, xml will parse the web when the server tomcat starts xml file, read the information of servlet and servlet mapping node, store it in a map set to ...

Added by jeevan_y21 on Fri, 10 Dec 2021 13:49:46 +0200

The lottery management system is realized through Mysql+Swing+jsp

catalogue Function Preview Back end main content Login panel Management panel Data panel    Menu bar Panel switching Operation database Main form key technology verification   Operating system process Beautify form Front end part   Registration interface jsp realizes front-end and back-end interaction Fu ...

Added by adityamenon90 on Sat, 04 Dec 2021 01:58:50 +0200

Understanding of java polymorphism

1, What is polymorphism The three characteristics of object-oriented are encapsulation, inheritance and polymorphism.Definition of polymorphism: parent class reference variables can point to subclass objects, allowing different objects to call the same method, that is, the same method can have different implementation forms according to differ ...

Added by jakem on Sat, 27 Nov 2021 01:09:59 +0200