获取cookie

当请求带cookie时, 可通过 req.getCookies 的方法获取cookie, 获取到的是一个 cookie 数组, 可遍历获取其值:

@WebServlet(name = "GetCookie")
public class GetCookie extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf-8");
        req.setCharacterEncoding("utf-8");

        Cookie[] coo = req.getCookies();
        if (coo != null){  //如果获取了空值会报空指针异常
            for (Cookie c : coo){
                String name = c.getName();
                String value = c.getValue();

                System.out.println(name + ": " + value);

            }
        }

    }
}