Ajax(异步请求)和传统(同步请求)区别
在服务器端判断request来自Ajax请求(异步)还是传统请求(同步):
两种请求在请求的Header不同,Ajax 异步请求比传统的同步请求多了一个头参数
1、传统同步请求参数
accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
accept-charset gb2312,utf-8;q=0.7,*;q=0.7
accept-encoding gzip,deflate
accept-language zh-cn,zh;q=0.5
cache-control max-age=0
connection keep-alive
cookie JSESSIONID=1A3BED3F593EA9747C9FDA16D309AF6B
host 192.168.101.72:8080
keep-alive 300
referer XXX
user-agent Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.0.15) Gecko/2009101601 Firefox/3.0.15 (.NET CLR 3.5.30729)
2、Ajax 异步请求方式
accept */*
accept-language zh-cn
referer XXX
x-requested-with XMLHttpRequest //AJax异步请求
content-type application/x-www-form-urlencoded,text/javascript
accept-encoding gzip, deflate
user-agent Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1;
Trident/4.0; QQDownload 598; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648;
.NET CLR 3.5.21022; CIBA; .NET CLR 1.1.4322; .NET CLR 3.0.4506.2152;
.NET CLR 3.5.30729; InfoPath.1)
host 192.168.101.72:8080
content-length 233
connection Keep-Alive
cache-control no-cache
cookie CSS=undefined; JSESSIONID=1B9AC25036290F7FB6823CCE1A24E541
可以看到 Ajax 请求多了个 x-requested-with 的头部信息,可以用它判断请求的方式:
if ("XMLHttpRequest".equals(request.getHeader("X-Requested-With"))) {
System.out.println('Ajax异步请求');
}else {
System.out.println('传统同步请求');
}