java - 我到了别人的项目，改了架包，然后报错，这个是哪里的错？架包问题？

Answer 1

Null pointer, look at each method from top to bottom

Answer 2

It is estimated that the jar package is missing, or the relevant jar packages are not all includedwebapp/WEB-INF/lib

Answer 3

Start from this Caused by The network problem may be that the connection is refused and there is no permission to access. If this is solved, then look at Start to listen directory: null. The configuration of the listener in your web.xml file (important jar package configuration is in the web.xml file) (C) It is possible that the jar package was deleted but it was configured in the web.xml file