【前端】Access-Control-Allow-Origin报错

gnn

问题：
Failed to load http://xx.com/mobile/service: The 'Access-Control-Allow-Origin' header contains multiple values '*, *', but only one is allowed. Origin 'http://localhost:8081' is therefore not allowed access.


原因：
出现这问题有可能是服务器端配置了跨域选项，在代码端也指定了跨域设置导致冲突，去掉一边的配置即可


解决方案：
代码中配置了跨域拦截器：

1. public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
   
2.         response.setHeader("Access-Control-Allow-Origin", "*");
   
3.         response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
   
4.         response.setHeader("Access-Control-Max-Age", "3600");
   
5.         response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
   
6.         response.setHeader("Access-Control-Allow-Credentials","true");
   
7.         return super.preHandle(request, response, handler);
   
8.     }
   

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nginx配置了：

1. add_header Access-Control-Allow-Origin *;
   
2.   add_header Access-Control-Allow-Methods GET,POST,OPTIONS;   
   
3.   add_header Access-Control-Allow-Headers X-Requested-With;

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去掉其中之一。