java - Error handling by redirection in spring download file controller -

this question nicely explains on how write download file controllers in spring. this question nicely explains post request cannot sent using response.sendredirect()

i user redirected same page error caused file download error. here workflow

1. user hits www.abc.com/index [controller has mapping /index.jsp , return modelandview]
2. at page, have file download has url www.abc.com/download?resource_id=123. [controller has mapping /download , returns void]
3. when there error in file download, user should redirected www.abc.com/index error display.
4. when there no error in file download, user stays @ same page , file download dialog appears.

following snippet forwarding:

@requestmapping(/download) public void execute(@requestparam(value = "resource_id" required = true) final string resource, final httpservletrequest request, final httpservletresponse response) {     try {         //some processing     } catch {         requestdispatcher dispatcher = request.getrequestdispatcher("/index" + "?is_downloaded=false");         dispatcher.forward(request, response)     } }  @requestmapping(/index) public void execute(@requestparam(value = "is_downloaded" required = false) final string isdownloaded, final httpservletrequest request) {     //do stuff here } 

step 3 problem.

• using forwarding changes url download url of report on error.
• using redirect response.sendredirect() hidden parameters impossible not modify url @ all.
• using redirect response.sendredirect() hidden parameters , introduce "?is_downloaded=false" @ end of url

can tell workaround this.

i've been having similar issue , solved below code.

i have following exception handler in controller. if there error takes care of re-direct , error messaging.

@exceptionhandler(filenotfoundexception.class) public modelandview exceptionhandler(exception ex) {     modelandview modelandview = new modelandview();     modelandview.setviewname("rescues/general");     modelandview.addobject("message", ex.getmessage());     return modelandview; } 

here requestmapping

@requestmapping(value = "s3download.request", method = requestmethod.get) @responsebody public responseentity<inputstreamresource> download(@requestparam(value = "s3key") string s3key)         throws ioexception {     httpheaders responseheaders = new httpheaders();     inputstreamresource inputstreamresource = s3downloadservice.gets3file(s3key, responseheaders);     return new responseentity<>(inputstreamresource, responseheaders, httpstatus.ok); } 

if files locally on server can use filesystemresource in place of inputstreamresource.

the service layer takes care of setting response header values on httpheaders object

responseheaders.setcontenttype(mediatype.parsemediatype(objectmetadata.getcontenttype())); responseheaders.setcontentlength(objectmetadata.getcontentlength()); responseheaders.setcontentdispositionformdata("attachment", filename);