示例架构图如下：

index.jsp 页面代码：

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
     请输入姓名：

UserServlet.java 文件如下：

package com.cloudwinsoftware.servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/UserServlet")public class UserServlet extends HttpServlet {private static final long serialVersionUID = 1L;public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html");response.setCharacterEncoding("UTF-8");response.setHeader("Cache-Control", "no-cache");String name = new String(request.getParameter("name").getBytes("ISO8859_1"),"UTF-8");PrintWriter out = response.getWriter();out.print("hello,"+name);out.flush();out.close();}}

运行效果如下：

在上面文本框中输入 名字，使其失去焦点 异步请求UserServlet，返回对应的值。