ajax返回有数据但走error(已解决，是因为我直接打开的静态页面，相当于打开本地文件，所以会出现跨域)

Question

后端说不允许设置跨域，所以将java代码打包发给我，解压后的目录结构

我将静态文件放入web文件夹中，然后在html里面编写ajax，发现返回有数据，但是ajax走的error，返回的结果是json没错，我ajax里面dataType不写或者写成text,json都不行。

返回的数据如下：

{"code":"ok","data":{"a_stat_list":[{"sum_reg":"83","hour":"10","sum_acc":"12"},{"sum_reg":"24","hour":"11","sum_acc":"25"},{"sum_reg":"73","hour":"12","sum_acc":"89"},{"sum_reg":"66","hour":"18","sum_acc":"74"}],"a_reg_list":[{"url_avatar":"/img/face.png","reg_time":"2019-07-26 09:08:19","name":"张三0","idnum":"440683199999999910"},{"url_avatar":"/img/face.png","reg_time":"2019-07-26 09:08:19","name":"张三9","idnum":"440683199999999919"}],"a_acc_list":[{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC300","url_avatar":"/img/face.png","name":"张三0","idnum":"440683199999999910"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC301","url_avatar":"/img/face.png","name":"张三1","idnum":"440683199999999911"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC305","url_avatar":"/img/face.png","name":"张三5","idnum":"440683199999999915"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC306","url_avatar":"/img/face.png","name":"张三6","idnum":"440683199999999916"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC307","url_avatar":"/img/face.png","name":"张三7","idnum":"440683199999999917"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC308","url_avatar":"/img/face.png","name":"张三8","idnum":"440683199999999918"},{"acc_time":"2019-07-26 09:08:20","acc_by":"DAC309","url_avatar":"/img/face.png","name":"张三9","idnum":"440683199999999919"}]}}

ajax走error打印的结果如下

Answer 1

跨域了，搜索“CORS”。

Answer 2

虽然静态资源放在后端服务里，但是用了Ajax还是相当于前后端分离的，发起Ajax请求是用户的浏览器，所以还是违背了同源策略,所以前后端分离必须设置跨域。还有走error回调，十有八九是请求信息没拼凑正确，注意dataType和Content-Type请求头。

 response.setHeader("Access-Control-Allow-Origin", "*");