Error: package javax.servlet does not exist import javax.servlet. *

I've created the directories correctly, copied the code and now does not compile and returns this error. I'm compiling the terminal using javac.

link

package com.example.web;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

    public class BeerSelect  extends HttpServlet {

        public void doPost ( HttpServletRequest request,
            HttpServletResponse response )
            throws IOException , ServletException{

            response.setContentType("text/html");
            PrintWriter out = response.getWriter();
                out.println("Beer Selection Advice <br>");
            String c = request.getParameter("color");
                out.println("<br> Got beer color " + c);

        }
    }

Stacktrace in the terminal:

src/com/example/web/BeerSelect.java:3: error: package javax.servlet does not exist
import javax.servlet.*;
^
src/com/example/web/BeerSelect.java:4: error: package javax.servlet.http does not exist
import javax.servlet.http.*;
^
src/com/example/web/BeerSelect.java:7: error: cannot find symbol
    public class BeerSelect  extends HttpServlet {
                                     ^
  symbol: class HttpServlet
src/com/example/web/BeerSelect.java:9: error: cannot find symbol
        public void doPost ( HttpServletRequest request,
                             ^
  symbol:   class HttpServletRequest
  location: class BeerSelect
src/com/example/web/BeerSelect.java:10: error: cannot find symbol
            HttpServletResponse response )
            ^
  symbol:   class HttpServletResponse
  location: class BeerSelect
src/com/example/web/BeerSelect.java:11: error: cannot find symbol
            throws IOException , ServletException{
                                 ^
  symbol:   class ServletException
  location: class BeerSelect
6 errors