Using servlet in Liferay portlet

Create a simple Servlet:

public class MyServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;
   
    public MyServlet() {
        super();
    }

    public void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        System.out.println("inside servlet");
    }

}

In web.xml, add:

    <servlet>
        <servlet-name>My Servlet</servlet-name>
        <servlet-class>com.example.servlet.MyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>My Servlet</servlet-name>
        <url-pattern>/myServlet</url-pattern>
    </servlet-mapping>

Remember url path to servlet is: /plugin-context-path/myServlet, not just /myServlet.