如何解决这个问题，以恢复我的代码使用xml解析器?因为一个错误

func postRestore(params : Dictionary<String, AnyObject!>, viewController: UIViewController, postCompleted: (status: String, genSettingsArray: NSArray, tmplArray: NSArray, tileArray: NSArray) -> ()) {
       let url = NSURL(string: postURL)
       var xmlParse:NSString  = ""
       var data : NSData!
       let request = NSMutableURLRequest(URL: url!)
       request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
       request.HTTPMethod = "POST"
       let param = params
       var error: NSError?
       if let body = NSJSONSerialization.dataWithJSONObject(param, options: nil, error: &error) {
           request.HTTPBody = body
       } else {
           println("JSON error: '(error)")
       }
       let task = NSURLSession.sharedSession().dataTaskWithRequest(request) { (data, response, error) in
           println(response)
           var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
           println(strData!)
           if data == nil {
               println("dataTaskWithRequest error: '(error)")
               return
           }
           let parser = NSXMLParser(data: data)
           parser.delegate = self
           parser.parse()
           postCompleted(status: strData! as String, genSettingsArray: self.generalSettingsArray, tmplArray: self.tmplArray, tileArray: self.tileArray)
           var page1 = self.generalSettingsArray.valueForKey("page1") as! NSArray
           var page2 = self.generalSettingsArray.valueForKey("page2") as! NSArray
           var page3 = self.generalSettingsArray.valueForKey("page3") as! NSArray
           var page4 = self.generalSettingsArray.valueForKey("page4") as! NSArray
           var page5 = self.generalSettingsArray.valueForKey("page5") as! NSArray
           for p1 in page1 {
               self.pagesArray.append(p1 as! String)
           }
           for p2 in page2 {
               self.pagesArray.append(p2 as! String)
           }
           for p3 in page3 {
               self.pagesArray.append(p3 as! String)
           }
           for p4 in page4 {
               self.pagesArray.append(p4 as! String)
           }
           for p5 in page5 {
               self.pagesArray.append(p5 as! String)
           }

           for pages in self.pagesArray {
               self.pageId = self.pageId + 1
               let realm = Realm()
               let page = Pages()
               page.id = self.pageId
               page.pageTitle = pages
               realm.write {
                   realm.add(page, update: true)
                   for settings in self.generalSettingsArray {
                       realm.create(GeneralSettings.self, value: settings, update: true)
                   }
                   for tmpl in self.tmplArray {
                       realm.create(Templates.self, value: tmpl, update: true)
                   }
                   for tile in self.tileArray {
                       realm.create(Tile.self, value: tile, update: true)
                   }
               }
           }
           println(Realm.defaultPath)
       }
       task.resume()
   }

因为我有一个这样的错误当它响应给我:

<NSHTTPURLResponse: 0x7fc541cb2f10> { URL: http://www.cloudstaff.com/sendmail/csa_restore.php } { status code: 200, headers {
   "Cache-Control" = "no-store, no-cache, must-revalidate, post-check=0, pre-check=0";
   Connection = "Keep-Alive";
   "Content-Encoding" = gzip;
   "Content-Length" = 20;
   "Content-Type" = "text/xml";
   Date = "Thu, 20 Aug 2015 02:23:11 GMT";
   Expires = "Thu, 19 Nov 1981 08:52:00 GMT";
   "Keep-Alive" = "timeout=15, max=100";
   Pragma = "no-cache";
   Server = "Apache/2.2.14 (Ubuntu)";
   "Set-Cookie" = "pamail=5b7dbglbh194e2um10u0ps0944; path=/";
   Vary = "Accept-Encoding";
   "X-Powered-By" = "PHP/5.3.2-1ubuntu4.19";
} }
/Users/rhoverf/Library/Developer/CoreSimulator/Devices/B234847F-7F5A-40FC-A510-B2667158A5DE/data/Containers/Data/Application/D1A6F8BD-508B-42A5-A338-C1BCC82042B3/Documents/default.realm
/Users/rhoverf/Library/Developer/CoreSimulator/Devices/B234847F-7F5A-40FC-A510-B2667158A5DE/data/Containers/Data/Application/D1A6F8BD-508B-42A5-A338-C1BCC82042B3/Documents/default.realm
fatal error: unexpectedly found nil while unwrapping an Optional value