123.8. Example 1: Reading Data from SAP
Overview
This example demonstrates a route which reads
FlightCustomer business object data from SAP. The route invokes the FlightCustomer BAPI method, BAPI_FLCUST_GETLIST, using an SAP synchronous RFC destination endpoint to retrieve the data.
Java DSL for route
The Java DSL for the example route is as follows:
from("direct:getFlightCustomerInfo")
.to("bean:createFlightCustomerGetListRequest")
.to("sap-srfc-destination:nplDest:BAPI_FLCUST_GETLIST")
.to("bean:returnFlightCustomerInfo");XML DSL for route
And the Spring DSL for the same route is as follows:
<route>
<from uri="direct:getFlightCustomerInfo"/>
<to uri="bean:createFlightCustomerGetListRequest"/>
<to uri="sap-srfc-destination:nplDest:BAPI_FLCUST_GETLIST"/>
<to uri="bean:returnFlightCustomerInfo"/>
</route>createFlightCustomerGetListRequest bean
The
createFlightCustomerGetListRequest bean is responsible for building an SAP request object in its exchange method that is used in the RFC call of the subsequent SAP endpoint . The following code snippet demonstrates the sequence of operations to build the request object:
public void create(Exchange exchange) throws Exception {
// Get SAP Endpoint to be called from context.
SAPEndpoint endpoint =
exchange.getContext().getEndpoint("bean:returnFlightCustomerInfo",
SAPEndpoint.class);
// Retrieve bean from message containing Flight Customer name to
// look up.
BookFlightRequest bookFlightRequest =
exchange.getIn().getBody(BookFlightRequest.class);
// Create SAP Request object from target endpoint.
Structure request = endpoint.getRequest();
// Add Customer Name to request if set
if (bookFlightRequest.getCustomerName() != null &&
bookFlightRequest.getCustomerName().length() > 0) {
request.put("CUSTOMER_NAME",
bookFlightRequest.getCustomerName());
}
} else {
throw new Exception("No Customer Name");
}
// Put request object into body of exchange message.
exchange.getIn().setBody(request);
}returnFlightCustomerInfo bean
The
returnFlightCustomerInfo bean is responsible for extracting data from the SAP response object in its exchange method that it receives from the previous SAP endpoint . The following code snippet demonstrates the sequence of operations to extract the data from the response object:
public void createFlightCustomerInfo(Exchange exchange) throws Exception {
// Retrieve SAP response object from body of exchange message.
Structure flightCustomerGetListResponse =
exchange.getIn().getBody(Structure.class);
if (flightCustomerGetListResponse == null) {
throw new Exception("No Flight Customer Get List Response");
}
// Check BAPI return parameter for errors
@SuppressWarnings("unchecked")
Table<Structure> bapiReturn =
flightCustomerGetListResponse.get("RETURN", Table.class);
Structure bapiReturnEntry = bapiReturn.get(0);
if (bapiReturnEntry.get("TYPE", String.class) != "S") {
String message = bapiReturnEntry.get("MESSAGE", String.class);
throw new Exception("BAPI call failed: " + message);
}
// Get customer list table from response object.
@SuppressWarnings("unchecked")
Table<? extends Structure> customerList =
flightCustomerGetListResponse.get("CUSTOMER_LIST", Table.class);
if (customerList == null || customerList.size() == 0) {
throw new Exception("No Customer Info.");
}
// Get Flight Customer data from first row of table.
Structure customer = customerList.get(0);
// Create bean to hold Flight Customer data.
FlightCustomerInfo flightCustomerInfo = new FlightCustomerInfo();
// Get customer id from Flight Customer data and add to bean.
String customerId = customer.get("CUSTOMERID", String.class);
if (customerId != null) {
flightCustomerInfo.setCustomerNumber(customerId);
}
...
// Put bean into body of exchange message.
exchange.getIn().setHeader("flightCustomerInfo", flightCustomerInfo);
}