请求不包含 multipart/form-data 或 multipart/mixed 流，内容类型标头为 false

Question

我想通过 ajax 发送图像，但出现以下异常：

org.apache.commons.fileupload.FileUploadBase$InvalidContentTypeException: the request doesn't contain a multipart/form-data or multipart/mixed stream, content type header is false

令人惊讶的是，当我定期（而不是通过 ajax）发送此表单时，表单工作正常。我尝试将 Content-Type 更改为 multipart/form-data 但随后出现此异常：

org.apache.commons.fileupload.FileUploadException: the request was rejected because no multipart boundary was found

这里是jquery代码：

$(document).ready(function() {
    $("#myform").submit(function(e) {
       e.preventDefault();
       var data = new FormData();
       data.append('file', document.formName.file.files[0]); // <-- possibly this line doesn't work
       $.ajax({
          url: 'upload.do',
          data: data,
          cache: false,
          contentType: false,
          processData: false,
          type: 'POST',
          success: function(res) {
          }
      });
   });
});

和形式：

 <form name="formName" enctype="multipart/form-data" id="myform" action="upload.do" method="POST">    
   <input type="file"  name="file" id="input-file" /> 
   <br>
   <input type="submit" value="Upload images" class="upload" />
 </form>

Answer 1

试试这个：

$(document).ready(function() {
    $('.upload').click(function() {
        var input = document.getElementById('input-file');
        file = input.files[0];
        var data = new FormData();
        data.append('file', file);
        $.ajax({
            url: 'upload.do',
            data: data,
            cache: false,
            contentType: false,
            processData: false,
            type: 'POST',
            success: function(res) {
            }
        });
    });
});