spring 3 upload many files - spring-mvc

Question

yeah,our customer want to upload more than one file.
we use spring 3 mvc.
the official example like this:
markup:
<form method="post" action="/form" enctype="multipart/form-data">
<input type="text" name="name"/>
<input type="file" name="file"/>
<input type="submit"/>
</form>
code:
#RequestMapping(value = "/form", method = RequestMethod.POST)
public String handleFormUpload(#RequestParam("name") String name,
#RequestParam("file") MultipartFile file) {
if (!file.isEmpty()) {
byte[] bytes = file.getBytes();
// store the bytes somewhere
return "redirect:uploadSuccess";
} else {
return "redirect:uploadFailure";
}
}
there is only one file,so i can write the file input name in the method.
but what should i do if i want to upload many files.
i could not write all the file input names because if is generated by the js code.
i only know that its name like 'attach_'
then ,what should i write in the method ? if i write like this
#RequestParam() MultipartFile file
or
#RequestParam("attach_") MultipartFile file
i'll get a error.

Answer 1

A much simpler way - works for me
/*** Upload Images ***/
#RequestMapping(value = "/images/upload", method = RequestMethod.POST)
public void upload(#RequestParam("file") List<MultipartFile> files, #RequestParam("user") String user) {
files.forEach((file -> System.out.println(file.getOriginalFilename())));
}

Answer 2

I have it working with Spring 3.0.4 (there was an issue in previous versions of Spring, so be sure to use >= 3.0.4).
To test it, you can use the following steps:
public class MultiPartFileUploadBean {
private List<MultipartFile> files;
public void setFiles(List<MultipartFile> files) {
this.files = files;
}
public List<MultipartFile> getFiles() {
return files;
}
}
The controller:
#RequestMapping(value = "/uploadtest", method = RequestMethod.POST)
public String uploadtestProcess(MultiPartFileUploadBean file, BindingResult bindingResult,
Model model) throws IOException {
... // binding check
StringBuilder sb = new StringBuilder();
List<MultipartFile> files = file.getFiles();
for(MultipartFile f:files)
sb.append(String.format("File: %s, contains: %s<br/>\n",f.getOriginalFilename(),new String(f.getBytes())));
String content = sb.toString();
model.addAttribute("content", content);
return "uploadtest";
}
The jsp:
<form method="post" action="/uploadtest" enctype="multipart/form-data">
<p>Type: <input type="text" name="type" value="multiPartFileSingle" size="60" /></p>
<p>File 1: <input type="file" name="files[0]" size="60" /></p>
<p>File 2: <input type="file" name="files[1]" size="60" /></p>
<p><input type="submit" value="Upload" /></p>
</form>
<c:if test="${not empty content}">
<p>The content uploaded: <br/>${content}</p>

Answer 3

I found clearer to use the MultipartHttpServletRequest object as a parameter to the controller method:
#RequestMapping(value = "/save", method=RequestMethod.POST)
protected String save(Model model, MultipartHttpServletRequest multipartRequest) {
MultipartFile file = multipartRequest.getFile("field-name");
// Also multiple files with same name
List<MultipartFile> files = multipartRequest.getFiles("multifield-name");
// ...
}
Link to the docs: http://docs.spring.io/spring/docs/current/spring-framework-reference/html/mvc.html#mvc-multipart-resolver-commons

Answer 4

You use model and form.
( Html / Jsp )
<form id="uploadForm" method="POST"enctype="multipart/form-data/charset=UTF-8">
//...multi file, add dynamic input
<input type="file" name="file"/>
<input type="file" name="file"/>
<input type="file" name="file"/>
<input type="file" name="file"/>
</form>
<input type="button" id="save_button" value="save" />
(Js)
var form = new FormData(document
.getElementById('uploadForm'));
$.ajax({
url : "/test/upload/file,
type : 'POST',
dataType : 'text',
data : form,
processData : false,
contentType : false,
success : function(response) {
if (response == "success") {
document.location.reload(true);
} else {
$("#editMsg").text("fail");
}
},
error : function(request, status, error) {
}
});
( Model )
public class fileModel {
private List<MultipartFile> file; // this name = input name
... setter, getter
}
( Controller )
#RequestMapping(value = "/upload/file", method = RequestMethod.POST)
public #ResponseBody String uploadFiles(fileModel model, HttpServletRequest req) {
return "success" // <-- debug. break point !! Your watch model.
}

Answer 5

You can find it here:
http://dhruba.name/2008/12/27/implementing-single-and-multiple-file-multipart-uploads-using-spring-25/