How to attach debug maven console applications

I will take maven quickstart project as example: step 1. create the simple-app project, open a terminal and type: mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-quickstart then input the groupId and artifactId:

step 2: open the generated folder simple-app in vscode, wait for the startup of java extensions:

step 3: set a breakpoint at App.java and F5, choose java, a new folder named .vscode should be created

step 4: in terminal, goto the simple-app folder and type mvn package to build the maven project and then type mvnDebug exec:java -Dexec.mainClass="com.ms.samples.App" to start the mvn debug: (be careful about the package name, it should be the groupId you have inputted in step 1)

step 5: back to vscode, modify the launch.json inside the .vscode folder and change the port to 8000 (the default debug port in maven), switch to debug view, change the

{
    "type": "java",
    "name": "Debug (Attach)",
    "request": "attach",
    "hostName": "localhost",
    "port": 8000
}