Guided package method in idea

java SE （idea Add jar package )

Create a new one java se project
stay src Create a new one under the file package, Any name

Then add what you want jar Stick the bag in

Right click the file , choice add as library

ok Just a matter of

java EE (idea 2020.3 Add shelf bag in )

Then choose what you want to join jar package
At this time, the error in the editor has disappeared
But it's not finished yet
Again , stay libraries below

Right click , This is just added jar package
The name should be different from yours

then apply That's it