post请求 url后面加参数 接收不到的，必须 放到send（"use"=user）形式

还要加上

xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");

servlet

1 package cn.itcast.controller; 2  3 import java.io.IOException; 4 import javax.servlet.ServletException; 5 import javax.servlet.annotation.WebServlet; 6 import javax.servlet.http.HttpServlet; 7 import javax.servlet.http.HttpServletRequest; 8 import javax.servlet.http.HttpServletResponse; 9 10 @WebServlet("/servlet/ServletDemo2")11 public class ServletDemo2 extends HttpServlet {12     private static final long serialVersionUID = 1L;13 14     public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {15     }16 17     public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {18         //System.out.println("ServletDemo2 doPost running");19         String username = request.getParameter("username");20         String password = request.getParameter("password");21         System.out.println(username+":"+password);22     }23 24 }

 

jsp

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