<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><script type="text/javascript"> function createXmlHttpRequest () { if (window.ActiveXObject) { return new ActiveXObject("Microsoft.XMLHTTP"); }else if (window.XMLHttpRequest) { return new XMLHttpRequest(); } } var xmlHttpRequest; function checkUserName (value) { var uname = value.value; var url = "全路径/sss/IndexServlet?uname=" + uname; xmlHttpRequest = createXmlHttpRequest(); xmlHttpRequest.onreadystatechange = returnValue; xmlHttpRequest.open("GET",url,true); xmlHttpRequest.send(null); } function returnValue () {
if(xmlHttpRequest.readystate == 4 && xmlHttpRequest.status == 200) { var value = xmlHttpRequest.responseText; alert(value)
s } }</script></head><body><form action="IndexServlet" method="get"><input type="text" name="uname" οnblur="checkUserName (this)"><input type="submit" value="提交"></form></body></html>
action或者servlet返回: response.setContentType("text/plain");//设置输出为文字流 response.setCharacterEncoding("UTF-8"); PrintWriter out = response.getWriter(); out.println(responseText); out.flush(); out.close(); return null;