Programmer Help

preface   today, let's talk about Lambda, which has puzzled me for a long time. Why do you say that? Because I never took the initiative to learn Lambda before. I didn't think about a lot of code using Lambda expressions. But recently, this Lambda expression appeared a little frequently, which affected my next study, so I went to learn it ...

[Log] Log framework in Java (I) JUL, Log4j [Log] Log framework in Java (middle) JCL and SLF [Log] Log framework in Java (Part 2): logback and log4j2 1. logback learning 1.1 logback introduction logback is another open source log component designed by the founder of log4j, and its performance is better than log4j logback is mainly divided in ...

SpringBoot -- container function 1. Component addition First, create two bean s, one called User and the other called Food. Previously, in SSM, component and attribute injection needed to be set in the Configuration file. The whole process can now be implemented in full code using SpringBoot. Create a Configuration class, mark it with @ Conf ...

1. What is a GUI The full name of GUI is Graphical User Interface. Graphical interface or graphical user interface refers to the user interface of computer operation environment which is displayed graphically. GUI is easier for users to use than the command line interface used by earlier computers. The wide application of GUI is one of the ...

Introduction: Circular dependency is a circular nested reference in N classes. If this circular dependency occurs in our daily development as a new object, the program will be called circularly at runtime until a memory overflow error occurs. Here's how Spring solves circular dependencies. First: Constructor Parameter Cyclic Dependency The Sp ...

The redis server uses port 6379 by default to communicate with the outside world, so we can actually implement a simple redis client on our own. This is done in java. Implementing a redis client consists of two main parts socket communicationEncoding and decoding of redis communication protocol The second part is mainly the implementation of ...

1. Introduction to ArrayList At the bottom of the ArrayList is an array queue, which is equivalent to a dynamic array. Compared to arrays in Java, its capacity can grow dynamically. Applications can use the ensureCapacity operation to increase the capacity of ArrayList instances before adding a large number of elements. This reduces the number ...

Local file upload and access service The core content of this chapter is to introduce the distributed file system, which is used to store the image, word, excel, pdf and other files of the application. Before introducing the distributed file system, let's introduce the use of native storage to store file resources. The core implementati ...

Resource constraints Time limit: 1.0s   Memory limit: 256.0MB Problem description You have a NxN pixel photo of a certain sea area, "." represents the ocean and "#" represents the land, as shown below: 　　....... 　　.##.... 　　.##.... 　　....##. 　　..####. 　　...###. 　　....... Among them, a piece of land con ...

catalog: 1. Comment statement (1) Paragraph comment: "/ * * /" (2) statement comment "/ /" 2. Keywords Words with special meanings: 1. All lowercase; 2. Special color mark 3. Data type Numerical typeSymbol / byteNon numerical typeSymbolintegerbyte(1),short(2),int(4),long(8)Booleanboolean(1)Floating point numberfloa ...