as mentioned in the title, I will describe the problems encountered in detail and post my upload code first
the diamante in the vue component is as follows
     //
        async upLoadFiles(){
          //base64
          this.$refs.cropper.getCropData((data) => {
            const file = this.base64ToFile(data,"");
            let param = new FormData();
            param.append("file",file);
            //FormDataget
            console.log(" param.get:",param.get("file"));
            // console.log(" file:",file);
            this.$apis.UserApi.updateUserIcon(param);
          });
          this.isShowModal = false;
        },the api,updateUserIcon code is as follows
  updateUserIcon(formData){
    return request({
      url:"user/updateUserIcon",
      method:"post",
      headers:{
        "Content-Type":"multipart/form-data", //
      },
      data:formData,
    }).then( res =>{
      console.log("updateUserIcon :",res);
      return res;
    }).catch( err =>{
      console.log("updateUserInfo :",err);
      return err;
    })
  }background error message is as follows
org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.io.IOException: org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was foundthe output of the browser console is as follows
 
 
