Programmer Think

1, Foreword In our daily development, we cannot avoid parameter verification. Some people say that the front end will verify in the form? In the back-end, we can directly judge the filtering regardless of how the front-end judges it. Our back-end needs to judge again for security. Because the front end is easy to request. When the test use ...

spring is a framework, a container and an ecosystem!. spring is singleton by default and supports circular reference. When changing to multiple instances, it is not supported. scope=“prototype” 1.bean life cycle class - > instantiation - > Object - > attribute filling (dependency injection: @ Autowired attribute assign ...

Use of FactoryBean FactoryBean FactoryBean is an interface. The interface declaration is as follows: package org.springframework.beans.factory; import org.springframework.lang.Nullable; public interface FactoryBean<T> { String OBJECT_TYPE_ATTRIBUTE = "factoryBeanObjectType"; @Nullable T getObject() throws Exception; ...

Advanced python has been greatly optimized on the basis of the first phase, making the whole more beautiful and easy to understand 7, List 7.1 common operations of list 7.1.1 search a,-----.statswith() . statswitch(): judge whether the string starts with a substring, put the substring in parentheses, and the results are Boolean types Tr ...

aggregate Java collection class is a kind of container, which can hold other data. It is used to store multiple objects with different quantities. It can also be used to store associative arrays (data pairs) with mapping relationships Overall, According to different storage data formats (single column or double column), it can be simply divid ...

catalogue final data final method final and private keywords final class In Java, final usually means "this cannot be changed". The reason for using final may be: design and efficiency. Learn about the final keyword from three possible situations: data, methods, and classes. final data In Java, data such as compile time cons ...

Source: http://t.cn/ESocliD Clean up resources in Finally or use the try with resource statement Use Finally Try with resource statement in Java 7 Give accurate exception handling information Record the exceptions you specified Throw an exception using a descriptive message Catch specific exceptions first D ...

catalogue 1, The essence of decorator: function closure: 2, Use method of decorator: Function closures that retain function parameters and return values: 3, Execution sequence of multiple decorators: 4, To create a decorator with parameters: 1, The essence of decorator: The essence of decorator is the syntax sugar of function closure ...

pandas: https://www.jianshu.com/p/840ba135df30 Learning direction: https://blog.csdn.net/zhiguigu/article/details/117924606 I. Basic Knowledge Chapter 1 starting 1.1 setting up programming environment https://www.python.org/ 1.2 build Python programming environment in different operating systems . . . -Download geony https://www.geany.or ...

I haven't updated the blog of C language learning for a long time. What I bring today is the knowledge points of the file part! 😋 1. Why do I need documents? Previously learned the code implementation of the address book, which can add and delete contacts in the address book. However, the address book is destroyed when your exe file is c ...