禁用cookie后,session失效,是因为session它是使用cookie来保存jsessionid值,如果禁用了cookie,session使用不了。
解决方案:我们认为将jsessionid的值添加到请求中,就可以。
http://localhost:8080/day9_2/demo2;jsessionid=....
可以通过URL重写:
方法1:response.encodeRedirectURL(java.lang.String url) 用于对sendRedirect方法后的URL地址进行重写
方法2:response.encodeURL(java.lang.String url) 用于对表单action和超链接URL地址进行重写
注意:对于以上操作,如果检测到浏览器禁用了cookie,会在路径上添加jsessionid的值,否则不会添加。
package com.it.servlet.session;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class Demo1Servlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
//获取session
HttpSession session = request.getSession();
//session是一个域对象
session.setAttribute("sname", "手机");
String path = response.encodeURL("/day9_2/demo2");
System.out.println(path);
response.getWriter().write("<a href='"+path+"'>跳转到demo2Servlet</a>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
package com.it.servlet.session;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Demo2Servlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String value = (String) request.getSession().getAttribute("sname");
System.out.println(value);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
注意:以上操作如果检测到浏览器禁用了cookie,会在路径上添加jsessionid值,否则,不会添加。