Programmer Think

Before HTML5, browsers and servers communicated through the HTTP protocol, so what's the use of introducing a WebSocket? Imagine a web page broadcasting a score of a football match live in text. Without a WebSocket, the client, or browser, usually updates the score dynamically in two ways: AJAX and long polling. What is the difference between ...

preface Recently, I have been reading the book "Effective C + +" 55 specific ways to improve program and design. It seems that there are some gains after reading it again and again. These classic books are and read repeatedly. Some ambiguous contents will be understood slowly over time. The first one is to regard C + + as a fe ...

IO stream primary coverage java. io. Use of File class (File: files and folders in the computer operating system) File class java.io.Filelei: abstract representation of file and directory pathnames, which is platform independentFile can create, delete and rename files and directories, but file cannot access the file content itself. ...

Seven rules for good Git to submit messagesSeparate the subject from the subject with a blank lineLimit subject lines to 50 charactersCapitalize subject lineDon't end the subject line with a periodUse imperative mood in subject lineLimit body to 72 charactersExplain with text1. Separate the main body from the main body with a blank lineThe git ...

1. Preface U-boot is an open source bootloader, which is used to guide operations and provide developers with testing and debugging tools. It is a simplified Linux system, which is mainly responsible for the initialization and boot of hardware. It has some tools as the boot program, often as the boot of embedded devices. When the real system s ...

1, Role inheritance Generally speaking, there are relationships between roles, such as ROLE_admin generally has the authority of admin and user. So how to configure this role inheritance relationship? In Spring Security, developers only need to provide a role hierarchy. for example SpringBoot_ Management (II) As an example, assume ROLE_dba ...

conditional rendering You can use wx:if = "" to determine whether to render the code block <view wx:if="{{flag}}">No rendering</view> <view wx:if="flag">Render</view> <view wx:if="">No rendering</view> <view wx:if=" ">Render</view> data: { flag: false, }, You can also use wx:e ...

Barman is an open-source excellent PG database backup tool based on Python, which integrates backup and recovery. It can make remote / local backup for single / multiple PG databases to enhance the security of business data and provide reliable help for DBA s to recover databases. Barman advantages It supports the backup of multiple versions ...

preface In vue, there are no more than three kinds of component relationships: Components need to communicate. In development, common communication methods include vuex, eventBus, props and emit, $parent and $children. In addition, there are also provide and inject, $attrs and $listeners. 1, vuex I believe you have used this a lot. Let's br ...

PackageManagerService is a very important module in the Android framework. It is related to application installation, uninstallation, Intent matching, package parsing, etc. Next, start PackageManagerService and get PackageManager object in Context to deal with the whole process.   this article is based on Android 10 source code analysis ...