The project uses a third-party jar package. When it was deployed as a war package, it reported an error that the referenced jar package could not be found. After checking it, it was not entered into the war package. Mainly when citing third-party jar packages, maven was not used, and it was directly introduced in the properties, so the packaging was not successful. Check the information and make the following changes:
Project--Right-click properties--deployment assembly--select add--add file--introduce third-party packages.
In this way, when deploying, third-party packages can be deployed together.