• How to judge whether an element exists in billion level data


    preface In daily work, it is often necessary to judge whether an element is in a collection. If you want to add a function to the browser, the function can inform the user whether the URL entered is a malicious URL. At this time, you have about 10 million data sets of malicious URLs. How […]

  • Illustrated how to use cache correctly


    Welcome to the official account of the personal public, “the back end school”, to learn and exchange weekly articles that are easy to understand and bring you quality articles, operating system, algorithms, etc., -Jvm, concurrent, Redis, etc. 1.1 Overview – caching is king over performance In the process of fighting against floods long ago, the […]

  • Analysis of Python custom calculation time filter implementation process


    This article mainly introduces the implementation process analysis of Python custom calculation time filter. The example code is introduced in detail in this article, which has certain reference learning value for your study or work. You can refer to the following for your friends When writing custom filters, because django.template.Library . filter () itself can […]

  • Summary of using dependency injection knowledge points in asp.net core filter


    How to use constructor injection for actionfilterattribute? The general custom filter can be used directly by identifying the characteristics [ContentFilter] Because the constructor requires parameters when it is used, then we can use this ServiceFilter In asp.net core, we can use servicefilter to fulfill this requirement. Servicefilter allows us to parse a service with IOC […]

  • El tree node name is too long


    Nothing can resist swallowing all the time. ——Tagore In the previous article, we wrote about using El tree to trigger the default click event of department management. However, when our department name is too long, we find that the display effect is unsatisfactory. After viewing the document, we can only realize it indirectly by ourselves. […]

  • Introduction to struts 2 development


    **As a development framework, Struts2 * * provides us with a good development template. Using * * Struts2 * * can reduce the burden of developers and enhance the readability of programs. Let’s talk about how to use * * Struts2 * * as a small example: Tools / development environment required for development:【1】 Jar […]

  • What ASP. Net core filter can do in simple terms – AOP


    1、 Foreword Before sharing the use of asp.net core filter, let’s talk aboutAOP, what is AOP? AOPFull nameAspect Oriented ProgrammingAspect oriented programming, also known as method oriented programming, is a technology to add functions to the program dynamically and uniformly without modifying the source code through precompiling and runtime dynamic agent. AOP technology uses a […]

  • Flask Sqlalchemy learning summary


    Initialization and configuration ORM(object relational mapper) object relational mapping. It refers to mapping object-oriented methods to relational objects in the database.Flask Sqlalchemy is a flask extension, which can support a variety of database background. We can operate the database without paying attention to the processing details of SQL. A basic relationship corresponds to a class, […]

  • . net component set component release update: Razor Edition + cross platform data components


    . net component set componentone v2020.0 Update1 has been officially released. This version focuses on cross platform data management and integration, which can significantly improve the productivity of. Net developers. In this update, componentone added a new method of connecting to online data sources, presenting data UI, data analysis and integrating data from different sources […]

  • Hellodjango article 09: make blog support markdown syntax and code highlighting


    By hellogithub-Dreamer The sample code involved in this article has been synchronously updated to the hellogithub team warehouse In order to make blog posts have a good layout and display a richer format, we use markdown syntax to write blog posts. Markdown is an HTML text markup language. As long as it follows its agreed […]

  • WXS module filtering information (time stamp) horizontal comparison Vue filter


    In the project, we often encounter the situation that we need to filter the data, that is, format the data we want. For example, format time, number accurate to several decimal places, etc.The filter in Vue is a little different from the filter in applet, so let me share the usage of these two types […]

  • Cache common problems and cache solutions


    avalanche Avalanche: a large number of keys in the cache expire at the same time, followed by a large number of requests falling on the database at the same time, resulting in abnormal database connection, or even crash. From the above description, as long as a large number of Keys expire at the same time, […]