The HTTP Status 404 error occurring in servlets.

The HTTP Status 404 error indicates that the requested resource cannot be found on the server. There are several possible reasons for encountering an HTTP Status 404 error in a servlet.

1. Error in URL path: Please make sure the URL path entered in the browser is correct, including the servlet name and any path parameters.
2. Servlet mapping error: Please verify if the servlet mapping configuration in the web.xml file is correct. Make sure the URL path corresponds to the servlet name.
3. Servlet not deployed: Make sure the servlet is properly deployed on the server. Check if the servlet’s deployment descriptor (e.g. web.xml or annotations) is correct.
4. There may be errors in the servlet code that could prevent the request from being handled correctly. Please review the servlet code and ensure it is error-free.
5. Server configuration error: Sometimes, there may be issues with the server’s configuration file, such as errors in the web.xml file or missing required library files on the server. Please check the server’s configuration file and ensure it is correct.

If none of the above methods can solve the problem, it is recommended to check the server log files for more detailed error information in order to better pinpoint the issue.