1.报错

com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [simple type, class org.springframework.session.data.mongo.MongoSession]: missing type id property '@class'

 at [Source: (String)"{"_id": "43386047-6d40-40fa-84e9-01b01ee00df5", "created": {"$date": "2021-05-15T13:44:27.095Z"}, "accessed": {"$date": "2021-05-15T13:44:27.096Z"}, "interval": "PT30M", "principal": null, "expireAt": {"$date": "2021-05-15T14:14:27.096Z"}, "attr": {"$binary": {"base64": "rO0ABXNyABFqYXZhLnV0aWwuSGFzaE1hcAUH2sHDFmDRAwACRgAKbG9hZEZhY3RvckkACXRocmVzaG9sZHhwP0AAAAAAAAB3CAAAABAAAAAAeA==", "subType": "00"}}}"; line: 1, column: 405]

session_mongodb.rar

2.运行老师的源码也报错：

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

2021-05-15 22:01:11.579 ERROR 15992 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat