Programmer Group

1, Application scenario of singleton mode Singleton Pattern refers to ensuring that a class has absolutely only one instance in any case and providing a global access point. The Singleton Pattern is a creation pattern. Singleton mode is also widely used in real life. For example, national president, company CEO, Department Manager, etc. In J2E ...

Foreword: Before we learn the topic String, let us recall whether there is a String type in the C language we learned before. The answer is No. String types are introduced in both C++ and java, which makes it easier for us to process strings on a daily basis. Previous articles: [java pieces] package, inheritance, combination Polymorphism, Abstr ...

Box2D (14) for libGDX Game Development LibGDX series, game development has unity3D Barabara, why use Java development? Because I'm a Java programmer, emm... I use libgdx less domestically. In most cases, I need to go to the official website and google to find information. If I learn from each other, I can contact you. Official description of li ...

Thread pool source code analysis is mainly divided into two parts, with the following problems to analyze 1. Creation of thread pool: how are threads in the thread pool created? How the task is performed. How to reuse after executing the task. When the task is squeezed, how to deal with these tasks? It is mainly expanded with execute() as the ...

On thread pool in high concurrency and multithreading definition Thread is a scarce resource. Its creation and destruction is a relatively heavy and resource consuming operation. Java thread depends on kernel thread. Creating thread requires operating system state switching. In order to avoid excessive resource consumption, it is necessary to ...

1, Interface design Jump from the activity where the avatar is located to the activity on the home page The page design after jump is as follows: Home page layer: ScrollView is used to realize scrolling text box Song layer: it hasn't been done yet. It is planned to adopt recyclerview <ImageView android:id="@+id/imageView6" ...

About rabbitmq prefetch count 1-1: cause I've always had a vague impression of prefetch count. I only know that instead of the original broker polling for consumer s, I can pull down n items at a time, but when I send message s one by one through the interface, I still poll, so I have this verification blog. 1-2: experimental code Configura ...

catalogue 1 basic usage of array 1.1 what is an array 1.2 creating arrays   1.3 use of arrays   2 array as parameter of method 2.1 basic usage 2.2 understanding of references   2.3 understanding 2.4 understand JVM memory area division 3 array as the return value of the method   4 array exercises 4.1 array to st ...

1. What is JDBC? Java database connectivity 2. What is the essence of JDBC? JDBC is a set of interfaces set at the top of sun company java.sql.*; (there are many interfaces under this software package) Interfaces have callers and implementers Interface oriented calling and interface oriented writing implementation classes belong to inte ...

Filter for Java Web 1. What is a Filter Filter filter, as the name suggests, is used to filter. What is it? In Java Web, the client accesses the resources in the server through the address, such as html page, jsp page, txt file, audio, video, picture and so on. However, we sometimes do not want all requests to access these resources on the se ...