how to handle huge volume of data transfer in gwt? - database

I have to transfer a huge number of data from database to client side using gwt RPC.
the data gets fetched by the service but during mapping of bean it returns error.
Returning cached instance of singleton bean 'org.springframework.context.annotation.internalScheduledAnnotationProcessor'
- on terminal
Something other than an int was returned from JSNI method '#com.google.gwt.user.client.rpc.impl.ClientSerializationStreamReader::readInt()': JS value of type Java Object com.google.gwt.dev.shell.JsValueOOPHM$DispatchObjectOOPHM, expected int - on browser
why might this happen?

It's a known bug in Chrome when using dev mode. It's been there for a while. It is tracked here. The only workaround for now is to use Firefox instead of Chrome.

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ExtJS 4 Using memory / paging memory proxy with remote data source

In my application I want to load a set of data from a remote source (in JSON format) to continue working with it completely locally (filtering, sorting, paging). store.load() operation have to get data from a remote source as well.
As I understand most suited store proxy type is Ext.ux.data.PagingMemoryProxy, but its sub class of Ext.data.proxy.Client, thus it can't work with remote data source (which I can set with url property for Ext.data.proxy.Server-based proxies).
If I add data directly to the store config all works as expected.
What proxy type is best suited for my situation?
I had a similar problem but not with a local file but gettin json from a server, I used a buffered store to do that:
http://docs.sencha.com/extjs/5.1/5.1.2-apidocs/#!/api/Ext.data.BufferedStore
(same on extjs 4)
Personally i use memory proxy to save datas only during execution. reloading or closing the page datas Always are deleted (sort of browser ram).
if equipment/get_all_devices is a JSON try to use a bufferedstore with json reader. if you use buffered store Ajax request use limit with your page size (pageSize: 25)
useful with big amount of datas

Auto update feature in passbook ios 7

How does automatic updates work in passbook available in backfield of the pass, how to use webserviceURL key to get update from the server.
in webserviceURL key i have provided remote path from where updated pass can be downloaded, but even after content changed in server, it does not reflects in pass.
This question has been asked so many times, in so many ways, in so many forums; mostly by people that are too lazy to read the manual, or are too inexperienced / incompetent to understand it.
The first paragraph of the Passbook Web Service Reference explains why simply adding a link to an updated pass will not work.
A REST-style web service protocol is used to communicate with your server about changes to passes, and to fetch the latest version of a pass when it has changed. The endpoints always begin with the web service URL, as specified in the pass, followed by the protocol version number. For example, a request for the latest version of the pass of type com.apple.pass.example and serial number ABC123 might look like the following:
The Passbook web service is an integral part of the Passbook eco system. Anyone wishing to issue passes that change their content (either in response to a push message or in response to a user requesting fresh content by pulling down on the back of the pass), needs to implement their own Passbook web service.
This entails building a server capable of responding to the following to authenticated requests from each device that has installed your pass.
There are 5 methods that your web service should respond to:
1. Registering a Device to Receive Push Notifications for a Pass
POST request to https://webServiceURL/v1/devices/deviceLibraryIdentifier/registrations/passTypeIdentifier/serialNumber
2. Getting the Serial Numbers for Passes Associated with a Device
GET request to https://webServiceURL/v1/devices/deviceLibraryIdentifier/registrations/passTypeIdentifier?passesUpdatedSince=tag
3. Getting the Latest Version of a Pass
GET request to https://webServiceURL/v1/passes/passTypeIdentifier/serialNumber
4. Unregistering a Device
DELETE request to https://webServiceURL/v1/devices/deviceLibraryIdentifier/registrations/passTypeIdentifier/serialNumber
5. Logging Errors
POST request to https://webServiceURL/v1/log
In order to have a pass respond to a manual refresh or push request you need to implement at least the first 3 methods. This is because the device will not issue any further requests until it has received a valid response to the registration request.
Furthermore, the web service must be available over https. An unsecured http service can be used for development, but production devices will only recognise a webServiceURL key that begins with https.

EJB 3.1 lookup returns null remote object

I am using EJB3 deployed on WAS 8.
I am accessing this EJB from my WEB server using Context.lookup.
This look up works fine and the entire application works fine for the first time after WAS is restarted.
However when I run the application for the second time, the look up does happen, but a NULL value is returned.
I dont get any exception or error or any logs on WAS.
Again if I restart the WAS, the application works well.
Can anyone please guide what the issue can be?
Remote references are connection-less proxies. If the application is redeployed/undeployed or there is network failure, the proxies are invalidated.
You can use ServiceLocator pattern for caching the references of the remote objects. You can remove & again re-create them with JNDI lookup when they become invalid.

Passing BSON to Silverlight client?

I am building a little app that has to communicate with a MongoDB database. Of course there is a web service in front of the DB and I am not trying to access the DB directly from silverlight. At first I thought to have this service return BSON objects in order to have the client manage them.
Is this even possible? It seems like I can't even add the BSON driver's dlls to the Silverlight app (they disappear from References immediately after closing the Add reference dialog, which seems to indicate they are not compatible with Silverlight).
Or maybe I got totally lost and misunderstood it all?? It's my first attempt with MongoDb...
Thanks!!
Why would you want to manipulate BSON objects on the client?
I'd say: let mongodb driver deal with BSON, then convert data to a more usable format (JSON / XML or similar) and pass it to silverlight client.
This is better because:
Client doesn't know about underlying database. What if BSON format got upgraded? You would have to recompile and deploy all clients.
Client doesn't know about underlying database. It communicates with the server using its own JSON (XML) based protocol. You might be able to even switch DB to MySQL and clients won't notice.

jqGrid on App Engine not rendering results when run from non local host !

wondering anyone else encountered this problem before - jqGrid works fine when working on my Google Appengine application on local machine (using eclipse+local datastore). When the same the application is deployed to actual domain, although the ajax data calls (i'm using XML format) are returning correct values (as confirmed using firebug ), the returned information does not appear as rows in the grid table. (Both firebug console and firefox error console shows same messages for both local and deployed requests).
Any helpful pointers ??
Solved !
I had not explicitly set the content-type as "text/xml" when returning data, so the XML data was still having the default header "text/html". This somehow was ignored when the data was served from local host.
Setting this header solved the issue.
Thanks.

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