首先，我将MultipartFile包装在一个表单支持对象中：
public class UploadBackingForm { private MultipartFile multipartFile; }然后我将其绑定到表单：
<form method="post" enctype="multipart/form-data"><@spring.bind "backingform.*"/><tr> <td><@spring.formInput 'backingform.multipartFile' '' 'file' /></td> <td> <button type="submit">Upload</button> </td></tr></form>
在控制器中，我分配一个验证器：
@InitBinderpublic void initBinder(final DataBinder binder) { binder.setValidator(new UploadValidator());}这是验证者：
public class UploadValidator implements Validator { private final Converter<String[], MyObject> converter = new MyObjectConverter(); @Override public boolean supports(final Class<?> clazz) { return UploadBackingForm.class.equals(clazz); } @Override public void validate(final Object target, final Errors errors) { final UploadBackingForm backingForm = (UploadBackingForm) target; final MultipartFile multipartFile = backingForm.getMultipartFile(); final List<String[]> uploadData = for (final String[] uploadDataRow : uploadData){ try { converter.convert(uploadDataRow); } catch (IllegalArgumentException e) { errors.rejectValue("multipartFile", "line.invalid", ...); } } }}验证器使用Converter将行项目转换为MyObj。
现在，doPost方法如下所示：
@RequestMapping(method = RequestMethod.POST)public String doUpload( @Valid @ModelAttribute("backingform") UploadBackingForm backingForm, final BindingResult result, final HttpSession session) throws IOException { final UploadConverter converter = new UploadConverter(); final List<MyObj> imports = converter.convert(backingForm.getMultipartFile().getInputStream()); }UploadConverter与UploadValidator大致相同：
public class UploadConverter implements Converter<InputStream, List<MyObject>> { private final Converter<String[], MyObject> converter = new MyObjectConverter(); @Override public List<MyObject> convert(final InputStream source) { final List<String[]> detailLines = final List<MyObject> importList = new ArrayList<MyObject>(detailLines.size()); for (final String[] row : detailLines) { importList.add(converter.convert(row)); } return importList; }}唯一的问题是验证和转换过程几乎是同一回事。幸运的是，上传文件不会很大，因此重复工作并不是大问题。
