Don’t panic in case of data tilt, teach you to easily obtain the slope of table tilt>>>

1、 When creating a servlet, write the following statement:

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

You will be prompted that the package javax. Servlet and the package javax. Servlet. HTTP do not exist

2, because the java compiler did not find the package javax. Servlet

3. The solution: copy the servlet-api.jar in the Lib directory of Tomcat installation package to the Lib sub file in the WEB-INF directory of the project folder, namely Web – > WEB-INF–lib．

4. After joining, remember that the methods of buildpath, eclipse and idea are different

Eclipse, select the corresponding jar package and right-click – > buildpath-> add to build path

Idea reference: http://www.cnblogs.com/miller-zou/p/5495168.html