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MySQL LIKE clause We know that the SQL SELECT command is used to read data in MySQL, and we can use the WHERE clause in the SELECT statement to obtain the specified record.   Friends who need the framework source code can see my personal profile and contact me, Recommended distributed architecture source code.     An equal sign c ...

This article is excerpted from "design patterns should be learned this way"1 definition of object pool modeObject Pool Pattern is a kind of creative design pattern. After objects are created and initialized in advance and put into the object pool, the object provider can use the existing objects to process requests, reducing the memor ...

This article is excerpted from "design patterns should be learned this way" 1 UML class diagram of command pattern The UML class diagram of the command pattern is shown in the following figure. 2 reconstruct the player control bar using command mode If we develop a player, the player has playback function, drag progress bar function ...

This article is excerpted from "design patterns should be learned this way" 1 about product hierarchy and product family Before explaining the abstract factory, we need to understand two concepts: product hierarchy and product family, as shown in the figure below. In the figure above, there are three kinds of figures: square, circle ...

This article is excerpted from "design patterns should be learned this way"1. Use delegation mode to simulate task allocation scenariosWe use code to simulate the business scenario where the boss assigns tasks to employees.First, create the IEmployee employee interface. public interface IEmployee { void doing(String task); } Creat ...

4.2.4 while loop Format: while COMMANDS; do COMMANDS; done while CONDITION; do Circulatory body done explain: CONDITION: cycle control CONDITION; Make a judgment before entering the cycle; Judgment will be made again after each cycle; If the CONDITION is "true", a loop is executed; The loop is terminated until the CONDITION ...

1: Why AQS Locks and collaboration classes (semaphores) have something in common: they are similar to a gate (only some threads are allowed to pass through), because they all use a common base class AQS at the bottom Because many of the above collaboration classes work similarly, you can extract a tool class and use it directly. For Reentrant ...

premise Regardless of the size of the system, most Spring Boot projects provide Restful + json interfaces for front-end or other service calls. The format is unified and standardized. It is not only a symbol that programs are kind to each other, but also a basic guarantee to reduce scolding during joint debugging. Generally, the response resu ...

1. Starting from version 1.20 of nginx, the official library is the same as the large version of epel, and the small version number of epel is updated. If you want to install the official, it is recommended to download the corresponding software package directly from the official yum install -y http://nginx.org/packages/centos/7/x86_64/RPMS/ng ...

preface Spring is already very familiar with spring. Spring container state events are also daily functions, which are often used for decoupling. However, sometimes events will be repeatedly monitored. At this time, they need to be handled. source is also used for special purposes. 1. demo Construct a Spring boot application and write a list ...