EXTJS and Spring MVC Portlet File Upload - spring

Question

I have successfully been able to upload a file to my ActionResponse method in my controller for my spring portlet using extjs. My problem is that extjs is expecting a json response in order to know the upload is complete, and the response for my action request renders out the entire portal.
I am needing a way to tell the response for my request to only be a json string.
here is my controller.
#Controller
#RequestMapping(value = "VIEW")
public class MediaRoomViewController {
private static final Logger _log = Logger.getLogger(MediaRoomViewController.class);
#RenderMapping
public String renderView(RenderRequest request, RenderResponse response, Model model){
return "view";
}
#InitBinder
protected void initBinder(PortletRequest request, PortletRequestDataBinder binder) throws Exception {
// to actually be able to convert Multipart instance to byte[]
// we have to register a custom editor
binder.registerCustomEditor(byte[].class, new ByteArrayMultipartFileEditor());
// now Spring knows how to handle multipart object and convert
}
#ActionMapping(params="action=uploadFile")
public String uploadFile(FileUploadBean uploadItem, BindingResult result,ActionResponse response) throws Exception {
_log.debug("Upload File Action");
ExtJSFormResult extjsFormResult = new ExtJSFormResult();
try{
if (result.hasErrors()){
for(ObjectError error : result.getAllErrors()){
System.err.println("Error: " + error.getCode() + " - " + error.getDefaultMessage());
}
//set extjs return - error
extjsFormResult.setSuccess(false);
}
// Some type of file processing...
System.err.println("-------------------------------------------");
System.err.println("Test upload: " + uploadItem.getFile().getOriginalFilename());
System.err.println("-------------------------------------------");
//set extjs return - sucsess
extjsFormResult.setSuccess(true);
}catch(Exception ex){
_log.error(ex,ex);
}
return extjsFormResult.toString();
}
here is my extjs file upload code
Ext.create('Ext.form.Panel', {
title: 'File Uploader',
width: 400,
bodyPadding: 10,
frame: true,
renderTo: self._Namespace + 'file-upload',
items: [{
xtype: 'filefield',
name: 'file',
fieldLabel: 'File',
labelWidth: 50,
msgTarget: 'side',
allowBlank: false,
anchor: '100%',
buttonText: 'Select a File...'
}],
buttons: [{
text: 'Upload',
handler: function() {
var form = this.up('form').getForm();
if(form.isValid()){
form.submit({
url: self._Urls[0],
waitMsg: 'Uploading your file...',
success: function(form,action) {
alert("success");
},
failure: function(form,action){
alert("error");
}
});
}
}
}]
});

Answer 1

There are several ways to go here:
Manually force response as text like this
response.setContentType("text/html"); //or json if u wish
responseText = "{'success':'true'}";
response.getWriter().write(responseText);
Use Jackson lib as covered here:
Spring 3.0 making JSON response using jackson message converter
Move on to Grails and forget about verbose MVC configs. My preferred method :)