Spring 控制器获取空对象

Question

我正在通过 jsp 表单向 spring 控制器发送一个对象。

JSP:

<form:form modelAttribute="uploadItem" action="/uploadObject" method="post" enctype="multipart/form-data">

<form:input path="fileData" accept="audio/mpeg" type="file" id="file-upload" name="file-upload" />

<form:input type="text" path="title" id="upload-title" name="upload-title"/>

<input type="image" src="..." alt="Upload"/>

</form:form>

模型服务：

 public void fillUploadMelodyModel(Model model) {
    fillAdminRootModel(model);
    model.addAttribute("uploadItem", new UploadedItem());
}

上传的项目：

public class UploadedItem {
  private CommonsMultipartFile fileData;
  private String title;
}

控制器：

 @RequestMapping(value = "/uploadObject", method = RequestMethod.POST)
    public String doUpload(UploadedItem uploadItem, BindingResult result, Principal principal) {
//at this point I get an empty object (null null values)
}

问题是什么？如何在 jsp?

中将对象传递给控制器

Answer 1

尝试像这样改变你的控制器

@RequestMapping(value = "/uploadObject", method = RequestMethod.POST)
public String doUpload(UploadedItem uploadItem, 
                      BindingResult result, 
                      @RequestParam("fileData") MultipartFile file,
                      @RequestParam("title") String title,
                      Principal principal) {
//Here you should receive your parameters
}

Answer 2

我认为您为文件 (file-upload) 和标题 (upload-title) 使用的名称与您的域 object 属性名称不同步。在 Jsp 页面中将您的名称更改为文件数据和标题。

Spring 控制器获取空对象

Spring controller get empty object

java

spring

jsp

spring-mvc

jspx