从表单上传文件和数据

Question

我正在使用playframework 2.1.5。我想发布一个包含数据和文件的表单。我已经定义了一个java类，其中包含数据的String属性和文件的java.io.File。

这是.scala.html方面：

    @helper.form(action = routes.Operations.addOperation(), 'enctype -> "multipart/form-data", 'id -> "picture_send_discussion", 'class -> "hide form-inline") {

@helper.inputText(myForm("name"), '_label -> s"${Messages.get("operation.name")} :")

<div class="fileupload fileupload-new" data-provides="fileupload">
    <div class="input-append">
    <div class="uneditable-input span2">
                <i class="icon-file fileupload-exists"></i>
                <span class="fileupload-preview"></span>
    </div>
    <span class="btn btn-file">
                <span class="fileupload-new">@Messages.get("bm.catalog.selectfile")</span>
                <span class="fileupload-exists">@Messages.get("bm.catalog.change")</span>
                <input type="file" name="picture"/>
    </span>
  <a href="#" class="btn fileupload-exists" data-dismiss="fileupload">@Messages.get("all.delete")</a>
  </div>
</div>
<button type="submit" class="btn un_btn--primary">@Messages.get("all.save")</button>

选择后，提交的文件属性始终为空。

这是我的控制器代码：

public static Result addOperation() throws IOException { 
    Form<AddOperationForm> boundForm = addOperationForm.bindFromRequest(); 
    Client user = getClient(); 
    if (boundForm.hasErrors()) { 
        return badRequest(operation_add_history.render(user, boundForm)); 
    } else { 
        AddOperationForm co = boundForm.get(); 
        Http.MultipartFormData body = request().body().asMultipartFormData();
        Http.MultipartFormData.FilePart picture = body.getFile("picture");
        etc ...

返回null的行是这一行：

    Http.MultipartFormData body = request().body().asMultipartFormData();