Programming VIP

1, Introduction "Wife" and "mother" fell into the water at the same time. Who should be saved first? As the saying goes: coding for five minutes, conflict resolution for two hours. As for Java development, the first reaction to seeing such exceptions as ClassNotFoundException and NoSuchMethodException is to arrange package ...

1. Background When submitting the flick task to yarn, we usually use the shade plug-in to package all the required jar packages into a large jar package, and then submit them to yarn through the flick run command. However, if there are frequent code changes, or many colleagues in the team need to develop multiple business modules in the same p ...

File upload and download File upload and download are very common functions. Many systems or software often use file upload and download. For example: QQ avatar, upload is used. The mailbox also has the function of uploading and downloading attachments. Upload of approved attachment materials in OA system. I Introduction to file upload (* * * ...

Concept: Java DataBase Connectivity, java database connection, java language operation database. Essence: it is actually an officially defined set of rules for operating all relational databases, namely interfaces. Each database manufacturer implements this set of interface and provides the database jar package. We can use this set of interfac ...

Database connection pool DBCP data source DBCP is the abbreviation of DataBase Connection Pool. It is an open source connection pool implementation under Apache organization. It is also a connection pool component used by Tomcat server. When using DBCP data source alone, it needs to be in the application Import two JAR packages from the. The de ...

The code was written in the last class. Unfortunately, we found that it crash ed when we clicked, because CHANGE_COMPONENT_ENABLED_STATE permission requires system permission 2021-12-17 23:09:15.078 4198-4198/com.android.things.privateapplication1 E/AndroidRuntime: FATAL EXCEPTION: main Process: com.android.things.privateapplication1, PID: ...

Recently, I encountered such a problem. The project is a spring cloud project. A main module (recorded as maincloud) depends on another sub module (recorded as subcloud). During the development process, it can run normally in the idea development tool environment. However, because the module needs to be packaged during testing, the subcloud pro ...

In recent days, I've tried to deploy the cloud by using the jar package of springboot to summarize the experience and problems encountered 1, The springboot project deploys cloud Linux 1. Pack 1. Set an unused port on the cloud, which will be occupied by spring boot running in the form of jar package 2. Change pom.xml packaging method ...