ajax跨域访问--. No 'Access-Control-Allow-Origin

js:

  

           var url = "http://172.16.3.25:8090/Project/oimReceive/uploadBase64ImgByCrossDomain";            $.ajax({                type: "POST",                url:url,                data:{"img":imgdata},                dataType: 'json',                async: true,                cache: true,                success: function(data) {                   //获取返回的data数据                }            });

JAVA:

        /** * IM设置更新  支持跨域 */@RequestMapping(value = "uploadBase64ImgByCrossDomain", method=RequestMethod.POST)@ResponseBodypublic HashMap<String, String> uploadBase64ImgByCrossDomain(String img,String sessionId,Model model,HttpServletResponse response) {response.addHeader("Access-Control-Allow-Origin", "*");   //用于ajax post跨域（*，最好指定确定的http等协议+ip+端口号）HashMap<String, String> dataMap = new HashMap<String, String>();String attachmentId = generateImage(img,sessionId);dataMap.put("attachmentId", attachmentId);return dataMap;}