Getting a list of mobility service providers that can transport a traveller from a pickup location to a drop location (Java)

In this use case, the user searches for mobility service providers that offer their service from a pickup location to a drop location

Search

Code snippets

Client calls the BAP server to trigger search:

    @PostMapping("/mobility/search_by_pickup_drop_location")
    public ResponseEntity searchByPickupDropLocation(
            @RequestHeader HttpHeaders headers,
            @RequestBody ClientSearchRequest request) {
        var response = bapApplicationService.generateSearchRequest(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": "search",
        "core_version": "0.9.1",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "transaction_id": "1209849124",
        "message_id": "12341242342",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "intent" : {
            "fulfillment": {
                "start" : {
                    "location" : {
                        "gps" : "12.9349377,77.6055586"
                    }
                },
                "end" : {
                    "location" : {
                        "gps" : "12.4535445,77.9283792"
                    }
                }
            }
        }
    }
}
*/

    public Response generateSearchRequest(ClientSearchRequest request, HttpHeaders headers) {

        var messageId = UUID.randomUUID().toString();

        // Check and create transaction id if not passed
        var txnId = StringUtils.hasText(request.getTransactionId())
                ? request.getTransactionId()
                : UUID.randomUUID().toString();

        // Construct the request similar to the example given above
        var context = Context.builder().domain(request.getDomain())
                .action(Context.ActionEnum.search)
                .messageId(messageId)
                .transactionId(txnId)
                .transactionId(UUID.randomUUID().toString())
                .timestamp(new Date().toString())
                .build();
        var intentBuilder = Intent.builder();

        // Construct fulfilment object for the request from pickup and drop location
        intentBuilder = intentBuilder.fulfillment(ClientAssembler.of(request.getFulfilment()));

        var searchRequest = SearchRequest.builder()
                .context(context)
                .message(SearchMessage.builder()
                        .intent(intentBuilder.build()).build()).build();

        return invokeSearch(searchRequest, headers);
    }
}

BAP server calls protocol search to the network

    public Response invokeSearch(SearchRequest request, HttpHeaders headers) {

        // Call to look up function which returns the the public key and BPP/BG Endpoint to be called
        var url = lookUp(headers);

        //Call BPP Search api
        var searchResponse = apiClient.post(url[0] + Context.ActionEnum.search,
                constructRequestHeaders(),
                request,
                Response.class);

        if (responseEntity.getBody() == null || responseEntity.getBody().getError() != null ||
                "NACK".equals(responseEntity.getBody().getMessage().getAck().getStatus())) {
            // Return custom error to the client
            return null;
        }
        return searchResponse.getBody();
    }

BAP receives protocol on_search

/*
Example Response JSON:
{
    "context": {
        "domain": "nic2004:60221",
        "country": "IND",
        "city": "std:080",
        "action": "on_search",
        "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": {
        "catalog": {
            "bpp/descriptor": {
                "name": "Big Mobility"
            },
            "bpp/providers": [
                {
                    "id": "yellow-mobility",
                    "descriptor" : {
                        "name": "Yellow Cabs"
                    },
                    "locations": [
                        {
                            "id": "closest-suv-spot",
                            "gps": "12.9349377,77.6055586"
                        },
                        {
                            "id": "closest-sedan-spot",
                            "gps": "12.9349377,77.6055586"
                        },
                        {
                            "id": "closest-sedan-outstation",
                            "gps": "12.9349377,77.6055586"
                        }
                    ],
                    "categories": [
                        {
                            "id": "spot_booking",
                            "descriptor": {
                                "name": "Spot booking"
                            }
                        },
                        {
                            "id": "outstation",
                            "descriptor": {
                                "name": "Outstation"
                            }
                        }
                    ],
                    "items": [
                        {
                            "id": "sedan_spot",
                            "descriptor" : {
                                "name" : "4 seater Sedan",
                                "images" : [
                                    "https://mock_bpp.com/images/sedan.jpg"
                                ]
                            },
                            "category_id": "spot_booking",
                            "location_id": "closest-sedan-spot",
                            "price" : {
                                "currency": "INR",
                                "value": "170"
                            },
                            "time": {
                                "label": "ETA",
                                "duration": "P14M"
                            },
                            "matched": true
                        },
                        {
                            "id": "suv_spot",
                            "descriptor" : {
                                "name" : "6 seater SUV ",
                                "images" : [
                                    "https://mock_bpp.com/images/suv.jpg"
                                ]
                            },
                            "category_id": "spot_booking",
                            "location_id": "closest-suv-spot",
                            "price" : {
                                "currency": "INR",
                                "value": "290"
                            },
                            "time": {
                                "label": "ETA",
                                "duration": "P12M"
                            },
                            "matched": true
                        },
                        {
                            "id": "sedan_outstation",
                            "descriptor" : {
                                "name" : "4 Seater Sedan",
                                "images" : [
                                    "https://mock_bpp.com/images/sedan-out.jpg"
                                ]
                            },
                            "category_id": "outstation",
                            "location_id": "closest-sedan-outstation",
                            "price" : {
                                "currency": "INR",
                                "value": "570"
                            },
                            "time": {
                                "label": "ETA",
                                "duration": "P17M"
                            },
                            "matched": true
                        }
                    ]
                },
                {
                    "id": "red-mobility",
                    "descriptor": {
                        "name": "Cabs 4 All"
                    },
                    "locations": [
                        {
                            "id": "closest-sedan",
                            "gps": "12.9349377,77.6055586"
                        }
                    ],
                    "categories": [
                        {
                            "id": "rental",
                            "descriptor": {
                                "name": "Rental"
                            }
                        }
                    ],
                    "items": [
                        {
                            "id": "sedan_rental",
                            "descriptor" : {
                                "name" : "Sedan 5 hours",
                                "images" : [
                                    "https://mock_bpp.com/images/sedan_rental.jpg"
                                ]
                            },
                            "category_id": "rental",
                            "location_id": "closest-sedan",
                            "price" : {
                                "currency": "INR",
                                "value": "200"
                            },
                            "time": {
                                "label": "ETA",
                                "duration": "P12M"
                            },
                            "matched": true
                        }
                    ]
                }
            ]
        }
    }
}
*/
    @PostMapping("/bap/on_search")
    public ResponseEntity onSearch(
            @RequestHeader HttpHeaders headers,
            @RequestBody OnSearchRequest request) {
        var response = bapCallbackApplicationService.onSearch(request, headers);
        return ResponseEntity.ok(response);
    }

    public Response onSearch(OnSearchRequest 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_search results

    // Endpoint for the client to poll the search data based on the message id
    @GetMapping("/mobility/on_search")
    public ResponseEntity searchByMessageId(
            @PathVariable(ClientRoutes.PARAM_MESSAGE_ID) String messageId,
            @RequestHeader HttpHeaders headers) {
        var data = bapApplicationService.getSearchData(messageId);
        return ResponseEntity.ok(data);
    }