Why don't you copy this content and set it in the response to user agent?Are you using any frameworks dedicated to MVC?I think that you can implement this feature in a better way without using Javascript.Below a snippet to create a file reading a content from Alfresco:
byte[] contentFile = null;
WebServiceFactory.setEndpointAddress(ALFRESCO_URL);
AuthenticationService authenticationService = WebServiceFactory.getAuthenticationService();
AuthenticationUtils.startSession(USERNAME, PASSWORD);
String ticket = WebServiceFactory.getCurrentTicket();
Reference ref = node.getReference();
Content[] readResult = contentService.read(new Predicate(new Reference[] { ref }, STORE, null), Constants.PROP_CONTENT);
Content content = readResult[0];
InputStream is = getContentAsInputStream(content.getUrl(), helper);
strUrl += "?ticket=" + ticket;
URL url = new URL(strUrl);
URLConnection conn = url.openConnection();
InputStream is = conn.getInputStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int bufferSize = is.available();
byte[] dati = new byte[bufferSize];
int readbyte = 0;
while ((readbyte = is.read(dati, 0, bufferSize)) > -1) {
baos.write(dati, 0, readbyte);
}
baos.close();
is.close();
contentFile = baos.toByteArray();
AuthenticationUtils.endSession();
Hope this helps.
