Applying an offer on a mobility service and getting discounted fare (Java)
In this use case, the user applies an offer on a mobility service and receives a discounted fare
Code snippets
Client calls the BAP server to trigger select:
@PostMapping("/mobility/apply_offer")
public ResponseEntity applyOffer(
@RequestHeader HttpHeaders headers,
@RequestBody ClientSelectRequest request) {
var response = bapApplicationService.generateSelectRequest(request, headers);
return ResponseEntity.ok(response);
}
BAP server generates the protocol request body
/*
Example Request JSON:
{
"context": {
"domain": "nic2004:60221",
"country": "IND",
"city": "std:080",
"action": "select",
"core_version": "0.9.1",
"bap_id": "https://mock_bap.com/",
"bap_uri": "https://mock_bap.com/beckn/",
"bpp_id": "https://mock_bpp.com/",
"bpp_uri": "https://mock_bpp.com/beckn/",
"transaction_id": "1209849124",
"message_id": "12341242343",
"timestamp": "2021-03-23T10:00:40.065Z"
},
"message": {
"order": {
"offers":[
{
"id": "offer_10"
}
]
}
}
}
*/
public Response generateSelectRequest(ClientSelectRequest request, HttpHeaders headers) {
// Generate message id
var messageId = UUID.randomUUID().toString();
// Check if transaction id exists in the request.
// Generate if not exists
var txnId = StringUtils.hasText(request.getTransactionId())
? request.getTransactionId()
: UUID.randomUUID().toString();
// Construct the Context based on the request parameters
var context = Context.builder().domain(request.getDomain())
.action(Context.ActionEnum.select)
.messageId(messageId)
.transactionId(txnId)
.transactionId(UUID.randomUUID().toString())
.timestamp(new Date().toString())
.build();
// Construct the protocol specific object to be passed to the BPP/BG
// Add the selected item(s) from the catalog with the selected offer to get a draft quote
var selectRequest = SelectRequest.builder()
.context(context)
.message(Message.builder().order(Order.builder()
.items(ClientAssembler.of(request.getItems()))
.build()).build())
.build();
return invokeSelect(selectRequest, headers);
}
}
BAP server calls protocol select to the network
public Response invokeSelect(SelectRequest request, HttpHeaders headers) {
// Call to look up function which returns the the public key and BPP Endpoint to be called
var url = lookUp(headers);
// Call BPP Select api from the returned endpoint.
// Construct request headers with the public key
var selectResponse = apiClient.post(url[0] + Context.ActionEnum.select,
constructRequestHeaders(),
request,
Response.class);
// Validate the received response
if (responseEntity.getBody() == null || responseEntity.getBody().getError() != null ||
"NACK".equals(responseEntity.getBody().getMessage().getAck().getStatus())) {
// Return custom error to the client
return null;
}
return selectResponse.getBody();
}
BAP receives protocol on_select
/*
Example Response JSON:
{
"context": {
"domain": "nic2004:60221",
"country": "IND",
"city": "std:080",
"action": "on_select",
"core_version": "0.9.1",
"bap_id": "https://mock_bap.com/",
"bap_uri": "https://mock_bap.com/beckn/",
"bpp_id": "https://mock_bpp.com/",
"bpp_uri": "https://mock_bpp.com/beckn/",
"transaction_id": "1209849124",
"message_id": "12341242343",
"timestamp": "2021-03-23T10:00:40.065Z"
},
"message": {
"order": {
"provider": {
"id": "yellow-cabs",
"locations": [
{
"id": "closest-sedan-spot",
"gps": "12.9349377,77.6055586"
}
]
},
"items": [
{
"id": "sedan_spot",
"price" : {
"currency": "INR",
"value": "170"
},
"time": {
"label": "ETA",
"duration": "P13M"
},
"location_id": "closest-sedan-spot",
"quantity": {
"selected": {
"count": 1
},
"available": {
"count": 4
}
}
}
],
"offers":[
{
"id": "offer_10"
}
],
"quote": {
"price": {
"currency": "INR",
"value": "160"
},
"breakup": [
{
"title": "Sedan Spot Booking",
"price": {
"currency": "INR",
"value": "170"
}
},
{
"title": "Service Charge",
"price": {
"currency": "INR",
"value": "10"
}
},
{
"title": "20 rupees off",
"price": {
"currency": "INR",
"value": "-20"
}
}
]
}
}
}
}
*/
@PostMapping("/bap/on_select")
public ResponseEntity onSelect(
@RequestHeader HttpHeaders headers,
@RequestBody OnSelectRequest request) {
var response = bapCallbackApplicationService.onSelect(request, headers);
return ResponseEntity.ok(response);
}
public Response onSelect(OnSelectRequest request, HttpHeaders headers) {
// Validate the headers received
var isHeadersValid = validateHeaders(headers);
// Construct and return error if the received headers are invalid
if (!isHeadersValid) return null;
// Store the data received based on message id for the client to poll
saveToDB(request);
return Response.of("ACK", null);
}
Client polls BAP to get the on_select results
// Endpoint for the client to poll the select data based on the message id
@GetMapping("/mobility/on_select")
public ResponseEntity selectByMessageId(
@PathVariable(ClientRoutes.PARAM_MESSAGE_ID) String messageId,
@RequestHeader HttpHeaders headers) {
var data = bapApplicationService.getSelectData(messageId);
return ResponseEntity.ok(data);
}