eclipse上的tomcat版本为8.5
引入项目tomcat版本为7.5
引入项目后工作区报错，打开报错文件，报错信息为：Multiple annotations found at this line:
- The superclass "javax.servlet.http.HttpServlet" was not found on the Java
Build Path
- The superclass "javax.servlet.http.HttpServlet" was not found on the Java
Build Path
解决方法：右键工程，打开propertities对话框，操作如下，选择自己的tomcat版本，我的是8.5，apply，退出即可