store multiple files in memory instead of disk

[Jiten Kothari]

hi,
Does anyone know how to store multiple files in memory and then retrieve multiple as file object, then clear the memory once the process is over.
Here I am storing it in disk, but my requirement is to store in memory, not in disk
please see comments

Any help is appreciated

def upload = {
		def user = session.userName
		def uploadFileCnt = 0
		def contentURL = grailsApplication.config.content.serverURL
		//def contentURL = "http://localhost:13001"
		
		def postFile
		def mpEntity = new MultipartEntity()
		def userDir
		
		if(request.method == 'POST') {
			
			Iterator itr = request.getFileNames();
			while(itr.hasNext()) {
				MultipartFile file = request.getFile(itr.next());
				
				if (file.empty){
					continue
					}
				
				def fileValidation = {
				
						String origFileType = file.getContentType();
						
						//System.out.println("file type is "+origFileType )
						log.error("file type is "+origFileType )
						
						def acceptContentType = [
													'application/pdf', 															//pdf file
													'application/x-pdf', 														//pdf-2 file
													'application/vnd.openxmlformats-officedocument.wordprocessingml.document',  //docx file
													'application/msword',														//doc file
													'application/rtf',															//rtf file
													'image/gif',																//gif file
													'image/jpeg',																//jpeg file
													'image/tiff',																//tiff file
													'image/x-ms-bmp',															//bmp file
													'text/plain'																//txt file
												]
						
						if (!acceptContentType.contains(origFileType))
							return false;
							else
							return true;
				}

				if((!file.empty) && (fileValidation())){
					
					def webRootDir = servletContext.getRealPath("/")
					userDir = new File(webRootDir, "/documentum/${user}")   
					userDir.mkdirs()
					file.transferTo(new File(userDir, file.originalFilename))
					postFile = new File(webRootDir, "/documentum/${user}/${file.originalFilename}")  //would like to store it in memory instead of disk

					def fBody = new FileBody(postFile, user)
				
					def fileType = (file.name).substring(4)
				
					mpEntity.addPart(fileType, fBody)
				
					uploadFileCnt ++
					
				}
			}
			
			def http = new HTTPBuilder(contentURL)
			
			http.request(POST) { req ->
						
				uri.path = '/bps/http/SubmitEmergencyPlanDocuments'
				uri.query = [UserName: user]
				
				req.entity = mpEntity
				
			}
			
			userDir.eachFile{
				if  (it.isFile()){
					it.delete()          // it deletes all the files inside ${user} directory --> /documentum/${user}/${file.originalFilename}
					}
				}
			
			
		if (uploadFileCnt == 0) {
		  flash.message = "${uploadFileCnt} documents uploaded. NOTE: You must submit annex in the PDF, DOC, or DOCX format. All other file formats are rejected."
	  } else {
		flash.message = "Successfully Uploaded ${uploadFileCnt} documents."
		}
		redirect(action: "documents", email: user)
	}
}