Question

我正在尝试使用请求对象的getCookies（）方法以累积的方式跟踪在每个servlet上添加的cookie，但令我惊讶的是，在第一个servlet中，请求对象知道其余所有存在的cookie servlet。它不是应该以累积方式显示吗？当请求对象仅位于第一个servlet上时，它如何才能获得其他servlet中的其余cookie？

我试图在Weblogic和Tomcat等各种服务器上进行检查，但都显示出相同的结果。即使尝试请求分派器的include（）方法或forward（）方法中的任何一个，我也得到相同的输出。

servlet1的代码

    @WebServlet("/serv1")
    public class Servlet1 extends HttpServlet {

protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    Cookie c1 = new Cookie("ck1", "Servlet 1 cookie 1");
    Cookie c2 = new Cookie("ck2", "Servlet 1 cookie 2");
    response.addCookie(c1);
    response.addCookie(c2);
    System.out.println("--------Cookies at Servlet 1 are------------");
    Cookie[] cookies = request.getCookies();
    for(Cookie i: cookies) {
        System.out.println(i.getName() + " " + i.getValue());
        out.println(i.getName() + " " + i.getValue());
    }

    RequestDispatcher requestDispatcher = request.getRequestDispatcher("./serv2");
    requestDispatcher.include(request, response);
}

}

servlet2的代码

@WebServlet("/serv2")
public class Servlet2 extends HttpServlet {
protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    Cookie c3 = new Cookie("ck3", "Servlet 2 cookie 3");
    Cookie c4 = new Cookie("ck4", "Servlet 2 cookie 4");
    response.addCookie(c3);
    response.addCookie(c4);
    System.out.println("--------Cookies at Servlet 2 are------------");
    Cookie[] cookies = request.getCookies();

    for(Cookie i: cookies) {
        System.out.println(i.getName() + " " + i.getValue());
        out.println(i.getName() + " " + i.getValue());
    }

    RequestDispatcher requestDispatcher = request.getRequestDispatcher("./serv3");
    requestDispatcher.include(request, response);
}

}

servlet3的代码

@WebServlet("/serv3")
public class Servlet3 extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    Cookie c5 = new Cookie("ck5", "Servlet 3 cookie 5");
    Cookie c6 = new Cookie("ck6", "Servlet 3 cookie 6");
    response.addCookie(c5);
    response.addCookie(c6);
    System.out.println("--------Cookies at Servlet 3 are------------");
    Cookie[] cookies = request.getCookies();
    for(Cookie i: cookies) {
        System.out.println(i.getName() + " " + i.getValue());
    }
}

}

删除cookie

System.out.println("Deleting the cookies...");

    for(Cookie i: cookies) {
        i.setValue("");
        i.setMaxAge(0);
    }

控制台中的预期结果必须如下

--------Cookies at Servlet 1 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
--------Cookies at Servlet 2 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
ck3 Servlet 2 cookie 3
ck4 Servlet 2 cookie 4
--------Cookies at Servlet 3 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
ck3 Servlet 2 cookie 3
ck4 Servlet 2 cookie 4
ck5 Servlet 3 cookie 5
ck6 Servlet 3 cookie 6
Deleting the cookies...

控制台中的实际结果如下

--------Cookies at Servlet 1 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
ck3 Servlet 2 cookie 3
ck4 Servlet 2 cookie 4
ck5 Servlet 3 cookie 5
ck6 Servlet 3 cookie 6
--------Cookies at Servlet 2 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
ck3 Servlet 2 cookie 3
ck4 Servlet 2 cookie 4
ck5 Servlet 3 cookie 5
ck6 Servlet 3 cookie 6
--------Cookies at Servlet 3 are------------
ck1 Servlet 1 cookie 1
ck2 Servlet 1 cookie 2
ck3 Servlet 2 cookie 3
ck4 Servlet 2 cookie 4
ck5 Servlet 3 cookie 5
ck6 Servlet 3 cookie 6
Deleting the cookies...

据我所知，我已经提供了这些信息。告知是否需要编辑或格式化。请提供基于控制流和更多实际可行输出的原因，而对理论的亲和力较小。

为什么请求对象没有以累积方式显示在每个servlet上添加的cookie？

0 个答案: