1、File->ProjectStruct->Artificats
2. Select your own module and main class and click ok
3. Complete the following operations
4. Build->BuildArtifacts->build starts to build jar
5. Finally, under the path specified in the screenshot in 3, you can see the generated jar
6. Supplement:
The problem that can be solved: java.lang.NoClassDefFoundError is reported when the jar is executed