Programmer Think

Author: fabricated belief Original text: https://segmentfault.com/a/1190000013803247 This paper introduces several main new features of 8.0 in relational database. You may already know that MySQL has provided NoSQL storage function since version 5.7, and some improvements have been made in 8.0. However, since this function is rarely used in p ...

1, Smelly and long if... else No more nonsense. First look at the following code publicinterface IPay { void pay(); } @Service publicclass AliaPay implements IPay { @Override public void pay() { System.out.println("===Launch Alipay payment==="); } } @Service publicclass WeixinPay implements IPay { ...

Characteristics of class inheritance - construction method The name of the constructor is consistent with the class name. Therefore, a subclass cannot inherit the constructor of its parent class.Constructor is used to initialize member variables. Therefore, in the initialization process of a subclass, the initialization action of the parent cl ...

i18n internationalization In development, Internationalization, also known as localization, means that a website (or application) can support multiple different languages, that is, different words can be displayed according to the language type and country / region of the user. It can make it easy for users in different countries and languages ...

BeanUtils.copyProperties(packedDTOS.get(0), docContent) Bean copying the attributes of the entity class can avoid many assignments, but pay attention not to overwrite when the dest element has a value.likeBOs != null && ! likeBOs. isEmpty() . List blank abbreviation Equivalent to! CollectionUtils.isEmpty(likeBOs)Common sense: null poi ...

1, Introduction to JSON JSON(JavaScript Object Notation) is a lightweight data exchange format. It is based on a subset of JavaScript, which is easy for people to write and read, and easy for machine parsing. JSON adopts a text format completely independent of the language, but it also uses habits similar to the C language family (inclu ...

1. Network programming (simple code, but deep complexity) Overview of 1.1 Network Programming 1.1.1 Classification Network programming: BIO,NIO,AIO BIO (base): Blocking communication (data flow is limited, waiting for the last batch to be released) (1) In the process of communication, there must be one sender and one receiver. (2) Before ...

1, Why can Nginx handle it asynchronously and non blocking Look at the whole process of a request: when the request comes, establish a connection, and then receive the data. After receiving the data, send the data. Specifically, the bottom layer of the system is the read-write event. When the read-write event is not re ...

1, Preface, introductory program, constant, variable 1.1 what is the Java language Java language is a high-level programming language launched by Sun Corporation (Stanford University Network) in 1995. The so-called programming language is the language of the computer. People can use the programming language to give orders to the computer ...

Learning is done preface Q: an Activity implements onClickListener. At this time, a Button uses setOnClickListener(this) Why is there no memory leak? A: because the View reference object will be released when the Activity is destroyed, there will be no memory leakage. Q: can you make it more detailed? Answer: Yes, Well, the window wi ...