OSS回调怎么添加自定义参数啊

这是我的代码 JSONObject jasonCallback = new JSONObject(); jasonCallback.put("callbackUrl", callbackUrl); jasonCallback.put("callbackBody", "filename=${object}&size=${size}&mimeType=${mimeType}&height=${imageInfo.height}&width=${imageInfo.width}}"); jasonCallback.put("callbackBodyType", "application/x-www-form-urlencoded"); String base64CallbackBody = BinaryUtil.toBase64String(jasonCallback.toString().getBytes()); respMap.put("callback", base64CallbackBody);

前端的 let formData = new FormData(); formData.append("OSSAccessKeyId", res.data.data.accessid); // //accessKeyId formData.append("policy", res.data.data.policy); // policy formData.append("Signature", res.data.data.signature); //签名 formData.append("success_action_status", 200); formData.append("callback", res.data.data.callback); //回调

          //formData.append("key", res.data.data.dir + this.option.name); // 存储在oss的文件路径
          //formData.append("file", data);

          _this.$axios
            .post(res.data.data.host, formData, {
              headers: { "Content-Type": "multipart/form-data" },
            })
            .then((res) => {