js-base64转换为file对象，ajax提交表单FormData

var img = "data:image/jpeg;base64,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";
function dataURLtoFile(dataurl, filename) {//将base64转换为文件
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new File([u8arr], filename, {type:mime});
}
function fileup() {
    var form=document.forms[0];
    var formData = new FormData();
    formData.append("myfile", dataURLtoFile(img,"123.png")); 
    formData.append("name", "123"); 
    formData.append("sex", "0"); 
    formData.append("employeeId", "123"); 
    formData.append("idCard", "123"); 
    formData.append("phoneNumber", "15829342473"); 
    formData.append("facesetToken", "021f4c37-aa70-4d03-b97a-a32230c79941"); 
    $.ajax({ 
     url: 'http://122.112.238.8:8080/api/v1/addface' , 
     type: 'POST', 
     data: formData, 
     async: false, 
     cache: false, 
     contentType: false, 
     processData: false, 
     success: function (returndata) { 
       console.log(returndata); 
     }, 
     error: function (returndata) { 
       alert(returndata); 
     } 
   }); 
}