Trouble getting my head around SAP NW GW

Hello Guys,

I am new to creating WebServices via Netweaver Gateway. I have two very basic questions here.

Multiple parameters to GET_ENTITY( ):

1)  I am implementing Get_Entity( ) (READ) method in my service. I am using the DD structure BAPIORDERS as the EntitySet. Now I have three of these fields viz., SdDoc, SalesOrg and SoldTo as KEY. If I need to pass all the 3 values, how will my URI look?

     P.S:  /sap/opu/odata/....../SALES_ORDERS(SdDoc='0000001'&SalesOrg='001'&SoldTo='0001') doesnt seem to work.

Demo Services:

2) I came across this brilliant blog Demo test cases by Andre Fischer and got to test the sample webservices available. Is there a way I could see the code implementations (Model and Runtime Provider classes) for those services.

Thanks,

Yuvaraj S