Cannot resolve class 'HttpServletRequest'

This error occurs when the class `HttpServletRequest` is not recognized by the compiler.

This class is part of the Java Servlet API and is used to represent an HTTP request made to a servlet.

To resolve this error, make sure that the Java Servlet API is included in your project's classpath. If you are using a web framework such as Spring or Struts, make sure that the appropriate libraries are included as dependencies.

If you are still encountering this error, check that the version of the Java Servlet API being used is compatible with your project's JDK version. Also, ensure that the import statement for `HttpServletRequest` is correctly spelled and that the class is being used in the correct context.