Receiving billing and shipping details during checkout and sending the final quote and payment terms (Java)

In this use case, the user provides all the information required by the diagnostic center to book an appointment and receives the final invoice with payment terms

Code snippets

BPP receives protocol init

/*
Example Request JSON:
{
    "context": {
        "domain": "nic2004:85195",
        "country": "IND",
        "city": "std:080",
        "action": "init",
        "core_version": "0.9.2",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "transaction_id": "1239890342",
        "message_id": "123793824",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "order": {
            "items": [
                {
                    "id": "health_checkup",
                    "quantity": {
                        "count": 1
                    }
                }
            ],
            "billing": {
                "name": "John Doe",
                "address": {
                    "door": "21A",
                    "name": "ABC Apartments",
                    "locality": "HSR Layout",
                    "city": "Bengaluru",
                    "state": "Karnataka",
                    "country": "India",
                    "area_code": "560102"
                },
                "email": "[email protected]",
                "phone": "+919876543210"
            },
            "fulfillment": {
                "type": "IN-PERSON",
                "end": {
                    "location": {
                        "id": "srs-koramangala",
                        "gps": "12.9349377,77.6055586"
                    },
                    "time": {
                        "range": {
                            "start": "2021-08-11T04:30:00.000Z",
                            "end": "2021-08-11T05:30:00.000Z"
                        }
                    },
                    "contact": {
                        "phone": "+919876543210",
                        "email": "[email protected]"
                    }
                }
            }
        }
    }
}
*/
    // BPP Init Endpoint
    @PostMapping("/bpp/init")
    public ResponseEntity init(
            @RequestHeader HttpHeaders headers,
            @RequestBody InitRequest request) {
        var response = bppApplicationService.init(request, headers);
        return ResponseEntity.ok(response);
    }

BPP processes the init

    public Response init(InitRequest request, HttpHeaders headers) {
        var initResponse = new OnInitRequest();
        // Validate the headers
        var isHeadersValid = validateHeaders(headers);
        // Construct and return error
        if (!isHeadersValid) return null;

        // Fetch the data based on the request
        var requestOrder = request.getMessage().getOrder();

        // Execute business logic here

        // Generate the response
        orderResponse = generateInitResponse(requestOrder);

        //invoke on_init api
        return invokeOnInit(orderResponse, headers);
    }
}

BPP generates response

/*
Example Response JSON:
{
    "context": {
        "domain": "nic2004:85195",
        "country": "IND",
        "city": "std:080",
        "action": "on_init",
        "core_version": "0.9.2",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "transaction_id": "1239890342",
        "message_id": "123793824",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "order": {
            "items": [
                {
                    "id": "health_checkup",
                    "quantity": {
                        "count": 1
                    }
                }
            ],
            "billing": {
                "name": "John Doe",
                "address": {
                    "door": "21A",
                    "name": "ABC Apartments",
                    "locality": "HSR Layout",
                    "city": "Bengaluru",
                    "state": "Karnataka",
                    "country": "India",
                    "area_code": "560102"
                },
                "email": "[email protected]",
                "phone": "+919876543210"
            },
            "fulfillment": {
                "end": {
                    "location": {
                        "id": "srs-koramangala",
                        "gps": "12.9349377,77.6055586"
                    },
                    "time": {
                        "range": {
                            "start": "2021-08-11T04:30:00.000Z",
                            "end": "2021-08-11T05:30:00.000Z"
                        }
                    },
                    "contact": {
                        "phone": "+919876543210",
                        "email": "[email protected]"
                    }
                }
            },
            "quote": {
                "price": {
                    "currency": "INR",
                    "value": "1100"
                },
                "breakup": [
                    {
                        "title": "Lab Charges",
                        "price": {
                            "currency": "INR",
                            "value": "1000"
                        }
                    },
                    {
                        "title": "Service Charge",
                        "price": {
                            "currency": "INR",
                            "value": "100"
                        }
                    }
                ],
                "ttl": "P1H"
            },
            "payment": {
                "uri": "https://api.bpp.com/pay?amt=$amount&txn_id=ksh87yriuro34iyr3p4&mode=upi&vpa=bpp@upi",
                "tl_method": "http/get",
                "params": {
                    "transaction_id": "ksh87yriuro34iyr3p4",
                    "amount": "1100",
                    "mode": "upi",
                    "vpa": "bpp@upi"
                },
                "type": "ON-FULFILLMENT",
                "status": "NOT-PAID"
            }
        }
    }
}
*/
    public OnInitRequest generateInitResponse(OrderDetails orderResponse) {
        var initResult = InitResponseBuilder.builder.result(orderResponse).build();
        // Convert response into protocol object similar to example above
        return initResult;
    }

BPP calls protocol on_init

    public Response invokeOnInit(OnInitRequest initResponse, HttpHeaders headers) {
        if(initResponse.getError() == null) {
            // Call BAP on_init api with the order response

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

            var response = apiClient.post(url[0] + Context.ActionEnum.on_init,
                    constructResponseHeaders(),
                    initResponse,
                    OnInitRequest.class);
            return Response.of("ACK", null);
        } else {
            return Response.of("NACK", null);
        }
    }