Programmer Group

J3 - white startTechnology (TCP/IP # UDP # Socket) Recently opened a project: https://gitee.com/j3_baiqi/communication Welcome to point out the project structure, coding problems and business direction 😊😊😊😊😊😊. 1, What is a Socket Encyclopedias: Vernacular is the interactive interface based on the network communication protocol ( ...

The way we often inject is similar to this@Service public class HelloService { @Autowired private BeanFactory beanFactory; @Autowired public HelloService(ApplicationContext applicationContext) { } @Autowired public void setEnvironment(Environment environment) { } }Whether constructor injection or attribute inj ...

Contents of this article preface Since the launch of Mybatis plus, more and more companies have chosen the Mybatis plus framework to replace the persistence layer framework Mybatis in their own projects. Because Mybatis plus not only has the flexibility of handwritten complex sql statements of Mybatis, but also has the general framework met ...

catalogue MyBatis environment initialization summary Create project module Add project dependency Mybatis simple configuration implementation. Create project startup class Environment test code implementation Announcement data layer MyBatis practice Business description Pojo class design Dao interface and method Implementation and a ...

Introduction The other day, a friend asked me what the following code would do. public class Main { public static void main(String[] args) { Integer i1 = null; System.out.println(i1 == 1); } } I said I would say NPE (NullPointerException) null pointer exception, although it does report null pointer exception after ex ...

1, Timer There is a Timer class under the java.util package, which is used to implement scheduled tasks 1. Code test Code implementation steps: 1. Create a timer object 2. Call the schedule polymorphic method of timer object and select the way to execute the task according to the different incoming parameters The first te ...

1. Stack 1.1 concept Stack: a special linear table that allows insertion and deletion of elements only at a fixed end. One end for data insertion and deletion is called the top of the stack, and the other end is called the bottom of the stack. The data elements in the stack follow the principle of Last In First Out LIFO (Last In First Out ...

1, Tomcat Foundation 1.1.Tomcat Foundation Tomcat It's essentially a Servle(Color is) Container, therefore Catalina(Katarina) is Tomcat Core of ， Other modules are for Catalina(Katarina) Provide support. such as :  adopt Coyote (k The module provides link communication, Jasper(Jasper) Module provision JSP Engine, Naming provide JNDI Servic ...

Preface The previous blog summarized the contents of CountDownLatch and Cyclic Barrier. The underlying concurrency control of these contents can not be separated from AQS (AbstractQueuedSynchronizer). Personally, there are fewer scenarios in which AQS is directly used to write concurrency tools in your work, and you won't go deep into the ...

Today, I happened to talk with some students. Let's share itSimpleDateFormat has thread safety problems. After Java 8, thread safe LocalDate, LocalTime, or LocalDateTime can be used, but to be honest, this LocalDate is much more troublesome than SimpleDateFormat.. but you can write a tool class to encapsulate common methods. So it doesn't seem ...