jar冲突
org.springframework.web.servlet.DispatcherServlet cannot be cast to javax.servlet.Servlet
分析：
Tomcat的jar包与本身的servlet-api的jar包冲突
解决方法：
视图解析器class写错
Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property ‘prefix’ of bean class
[org.springframework.web.servlet.view.InternalResourceView]: Bean property ‘prefix’ is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?
分析：
视图解析的class是：
org.springframework.web.servlet.view.InternalResourceViewResolver
不是：
org.springframework.web.servlet.view.InternalResourceView