最近在采用jquery ajax调用http请求时,发现了一系列问题:

如采用firebug调试API请求(这个API是自己服务器的应用),看到服务器明明返回200状态,response返回数据也是json格式,但ajax返回的error。

在排除json数据格式不正确的原因之后,发现了ajax error函数返回“networkerror failed to execute ‘send' on ‘xmlhttprequest' failed to load ‘http //“ XMLHttpRequest.status=0,就是没有初始化。

后来才知道是跨域问题(CORS),因为程序调用的是远程服务器的API,服务器不允许跨域调用。如果只是简单的方法,只需要在程序的response添加支持跨域的header添加属性”Access-Control-Allow-Origin: * “即可。

如java 服务器代码:

yourownvariable.setHeader("Access-Control-Allow-Origin:", "origin url of your site");

yourownvariable.setHeader("Access-Control-Allow-Methods", "GET, POST,PUT");

如果是配置nginx服务器(如果是其他服务器,可以参考:I want to add CORS support to my server),需要在nginx.conf配置文件添加一下内容:

#

# Wide-open CORS config for nginx

#

location / {

if ($request_method = 'OPTIONS') {

add_header 'Access-Control-Allow-Origin' '*';

add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';

#

# Custom headers and headers various browsers *should* be OK with but aren't

#

add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';

#

# Tell client that this pre-flight info is valid for 20 days

#

add_header 'Access-Control-Max-Age' 1728000;

add_header 'Content-Type' 'text/plain charset=UTF-8';

add_header 'Content-Length' 0;

return 204;

}

if ($request_method = 'POST') {

add_header 'Access-Control-Allow-Origin' '*';

add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';

add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';

add_header 'Access-Control-Expose-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';

}

if ($request_method = 'GET') {

add_header 'Access-Control-Allow-Origin' '*';

add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';

add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';

add_header 'Access-Control-Expose-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';

}

}