Javaweb: Error message the superclass "Javax.servlet.http.HttpServlet" is not found on the Java Build Path

Javaweb: Error message the superclass "Javax.servlet.http.HttpServlet" is not found on the Java Build Path

Typically because the server runtime is not added, configure the server runtime for the project: Right-click the project name, select Build path->configure build path-> pop-up Java build The Path dialog box is selected by default Libraries tab, right click Add library....-> pop-up Add Library dialog, select Server Runtime->next, Finish, back to Java Build Path, click OK. Then, the error disappears.

Note: If you follow the above method, if you open the Server runtime blank, you need to set up Apache server. Set the method to: Window->preferences->server->runtime environment, add-on, select the Apache version and click Next. Then fill in the installation (unpacked) address of your Apache server software.

Javaweb: Error message the superclass "Javax.servlet.http.HttpServlet" is not found on the Java Build Path