Question

So here is the code I have so far:

Flex Code

<?xml version="1.0" encoding="utf-8"?>

<fx:Declarations>


    <s:RemoteObject id="getStockPrices" result="result(event)" destination="blazeDsService"
                    endpoint="http://localhost:8400/flexspring/messagebroker/streamingamf"/>

</fx:Declarations>


<mx:DataGrid  x="10" y="295" width="910" height="211" creationComplete="getStockPrices.getQuotes();"
             dataProvider="{getStockPrices.getQuotes.lastResult}" >
    <mx:columns>
        <mx:DataGridColumn headerText="Stock Ticker" dataField="name" />
        <mx:DataGridColumn headerText="Price" dataField="price"/>
        <mx:DataGridColumn headerText="Hi" dataField="col3"/>
        <mx:DataGridColumn headerText="Low" dataField="col4"/>
        <!--<mx:DataGridColumn headerText="Adverage" dataField="col5"/>
        <mx:DataGridColumn headerText="Graph" dataField="col6"/>-->
    </mx:columns>
</mx:DataGrid>


<mx:Button label="Retrieve Stocks" click="retrieveStocks()"/>

And this is the java Class file. This returns and arraylist:

package flex;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.springframework.flex.remoting.RemotingDestination;
import org.springframework.flex.remoting.RemotingInclude;
import org.springframework.stereotype.Service;

import supportingClasses.StockQuote;

@Service

@RemotingDestination

public class BlazeDsService {

private static final String[] MASTER_LIST = {"C", "FNM", "FRE", "F", "GOOG", "AIG", "CSCO", "MSFT", "AAPL", "YHOO", "BSX", "PORT","F", "TNT", "ESP", "RET", "VBN", "EES"};


@RemotingInclude
public List<StockQuote> getQuotes(){
    List<StockQuote> list = new ArrayList<StockQuote>();
    Random r = new Random();
    for (String s:MASTER_LIST){
        StockQuote sq = new StockQuote();
        sq.setName(s);
        sq.setPrice(r.nextInt(50));
        list.add(sq);
    }
    return list;
}

}

At the minute a button needs to be pressed to refresh the data. I want to get rid of this and poll the information every x seconds. Can this be done?

Do I need to change my set-up? create some publish – subscribe pattern and use Streaming channels?

Thanks

Answer 1

If you just want to call the getQuotes method at every X seconds you can use a timer in Flex, no need for messaging. If you want to be notified when a stock value changed you can use a consumer on the flex side which is subscribed to the same destination where the server is adding messages. You can find a sample doing just that in the BlazeDS samples folder, under traderdesktop folder.