How can I pass parameter as post to endpoint using RestTemplate in springboot?

Question

I am using RestTemplate in my project to make a post request to an endpoint. Basically I have lambda function written in nestjs. I am injecting lambda service in my java project. If vehicleName if condition passes, I would like to POST that vehicleName to the url. Is there any suggestions on how I can achieve this? I would be testing my application using this command

curl -X POST "https://gdxdispatcher.dev.awstrp.net/dispatcher/service/api/message" -H "accept: */*" -H "Content-Type: application/json" -d "{\"vehicleType\":\"US Mutual Fund,VIP\",\"source\":\"PCS_DATACACHE_TOPIC\"}"

Here is my code

private void callLambdaService(String vehicleTypesParamValue)
    {
        final String url = "http://localhost:3000/dispatcher/service/api/message";

        final String zMETHOD = "callLambdaService - ";

        RestTemplate restTemplate = new RestTemplate();
        restTemplate.exchange("url", HttpMethod.POST, vehicleName, String.class);

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        String result = restTemplate.getForObject(url, String.class);

        VehicleType vehicleName=null;

        String[] vehicleTypes = vehicleTypesParamValue.split(",");
        Set<VehicleType> results = new HashSet<>();
        try
        {
            for (String vehicleTypeParam : vehicleTypes)
            {
                vehicleName =
                        vehicleTypeFactory.getVehicleTypeByIspName(
                                vehicleTypeParam);
                if (vehicleName == null)
                {
                    LOGGER.warn("No codes for products or vehicle types were supplied");
                }
                else if (vehicleName.equals("US Mutual Fund"))
                {
                    LOGGER.info(zMETHOD + "Vehicles provided: "
                            + vehicleName.getIspName());

                }
                else
                {
                    LOGGER.warn(
                            String.format("Unknown vehicle type provided: [%s]",
                                    vehicleName.getIspName()));
                }

            }
        }catch (Exception e) {
            LOG.error("Unable to get vehicletype data", e);
        }

    }

Answer 1

Well, following the instructions:

1. Create headers which will be a data structure representing HTTP request.

   HttpHeaders headers = new HttpHeaders();
   headers.setContentType(MediaType.APPLICATION_JSON);
   

2. Build a JSONObject from org.json package that is a modifiable set of name/value mappings and put names and values.

   JSONObject requestBody = new JSONObject();
   requestBody.put("vehicleType", "US Mutual Fund,VIP");
   requestBody.put("source", "PCS_DATACACHE_TOPIC");
   

3. Create our HttpEntity that represents an HTTP request or response, in this case request consisting of headers and body.

   HttpEntity<String> request = new HttpEntity<>(requestBody.toString(), headers);
   

4. Create a new resource by posting an object to the given URI template. It returns the result as automatically converted to the type specified in the responseType parameter. Then we define a ObjectNode as our resource and response type as our result.

   ObjectNode result = restTemplate.postForObject("https://gdxdispatcher.dev.awstrp.net/dispatcher/service/api/message", 
                                                   request, ObjectNode.class);