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Method area of jvm definition (1) The method area, like the java heap, is a memory area shared by all threads (2) The method area is created when the jvm starts, and its actual physical memory space can be discontinuous like the java heap area (3) The size of the method area, like the heap space, can be fixed or expanded (4) The size of the m ...

   students, today we will deeply analyze the source code of HashMap. I believe many students will be asked about the source code during the interview. Which one is the most asked? Most students will definitely think of HashMap. Through the study of this article, you will be able to easily master the source code knowledge of HashMa ...

[Java] multithreading (taking the realization of video function as an example) step1: how to realize video Video is realized by pictures, so we only do two things: 1) Find an interface that can call the camera 2) Use this interface to get the picture of every moment 3) Draw these pictures in a continuous cycle Step 2: why can't you turn ...

1. What is a business? Database transaction is simply to operate several different SQL statements as a whole, either all successful or all failed. It has four characteristics: atomicity, consistency, isolation and persistence. Spring transaction is a transaction processing mechanism encapsulated in database transaction. It has two manageme ...

1, PrefaceSpringBoot 2.6.x does not recommend the use of circular dependency, which is good news. Springboot gradually guides developers to write standard code from the bottom. At the same time, it is also sad news. The application scenarios of circular dependency are too wide.If you upgrade from a lower version to 2.6 x. Then the first problem ...

springboot: common annotations 1, spring common annotations Package scanning + Component annotation @Component: Refers to various components @Controller,@Service,@Repository Can be called@Component. @Controller: Control layer @Service: Business layer @Repository: Data access layer selector @Conditional，Only when the specified condit ...

Even if you do web development, you will encounter various algorithm problems that need to be solved. This paper extracts some classic hand training algorithms and provides relevant reference answers, hoping to be helpful to you In addition, I have collated and collected interview knowledge points from more than 20 companies for more than 20 ...

1, Scene source In daily development practice, it is often necessary to use tools (such as Postman and curl commands) to build http requests for development and testing. When an interface requiring token authentication is encountered, it may be necessary to log in to additional pages or request other interfaces to obtain tokens. If it is necess ...

1. Requirements of chat program Through the previous study, we can see that the client and server can interact normally, so can we make a chat applet ourselves? Now we can define some requirements ourselves, such as: 1. After the server receives a message from the client establishment request, we need to push the message to other clients, whic ...

In android development, images are very easy to cause OOM exceptions. In most cases, images need to be compressed and displayed. This paper mainly records several common image compression methods in development 1, Mass compression Change the bit depth and transparency of the picture on the premise of maintaining the pixels (that is, erase (as ...