The web application [ ] registered the JDBC driver [net.sourceforge.jtds.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver

出现以下错误时，我找了很多方法，都未解决，网上有很多，最后我实在无奈，怀疑会不会是Tomcat的原因，更换了一个版本之后就好了。
The web application [ ] registered the JDBC driver [net.sourceforge.jtds.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.

你也可以试试这种方法哦。