Unable to call Salesforce API using Spring RestTemplate

Question

I am developing an application Java + Salesforce and calling salesforce services using the Spring RestTemplate API, but seems getting some error. Any help ?

public class RestTemplateExample {

    final static String TOKEN_URL = "https://ap5.salesforce.com/services/oauth2/token";

    public static void main(String[] args) {

        HttpHeaders headers = new HttpHeaders();
        headers.add("client_secret", "XXXXXXXXX");
        headers.add("client_id", "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");
        headers.add("grant_type", "password");
        headers.add("username", "[email protected]");
        headers.add("password", "XXXXXXXXXXXX");
        headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));

        HttpEntity<String> entity = new HttpEntity<String>("", headers);

        RestTemplate restTemplate = new RestTemplate();
        ResponseEntity<String> result = restTemplate.exchange(TOKEN_URL, HttpMethod.POST, entity, String.class);
        System.out.println("TOKEN DETAILS :: "+result.getBody());
    }
}

When I checked through postman it works fine.

2017-10-14 18:40:35 DEBUG o.s.web.client.RestTemplate - Created POST request for "https://ap5.salesforce.com/services/oauth2/token"
2017-10-14 18:40:35 DEBUG o.s.web.client.RestTemplate - Setting request Accept header to [text/plain, application/json, application/*+json, */*]
2017-10-14 18:40:35 DEBUG o.s.web.client.RestTemplate - Writing [] using [org.springframework.http.converter.StringHttpMessageConverter@2141a12]
2017-10-14 18:40:37 DEBUG o.s.web.client.RestTemplate - POST request for "https://ap5.salesforce.com/services/oauth2/token" resulted in 400 (Bad Request); invoking error handler
Exception in thread "main" org.springframework.web.client.HttpClientErrorException: 400 Bad Request
    at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:78)
    at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:700)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:653)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:613)
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:531)
    at com.example.RestTemplateExample.main(RestTemplateExample.java:29)

https://ap5.salesforce.com/services/oauth2/token?client_id=XXXXXXXX&client_secret=XXXXXXXXXXX&username=XXXXXXXXXXXXX&password=XXXXXXXXXXXX&grant_type=password

Answer 1

This needs to be implemented like below which works fine.

// create the Map of the MultiValueMap
MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
map.add("grant_type", "password");
map.add("client_id", "XX");
map.add("client_secret", "XXX");
map.add("username", "XX");
map.add("password", "XXX");

// RestTemplate
RestTemplate restTemplate = new RestTemplate();
Map<String, String> token = restTemplate.postForObject(TOKEN_URL, map, Map.class);
System.out.println("--------------------------------------------");
System.out.println("Access Token  :: "+token.get("access_token"));
System.out.println("Instance Url  :: "+token.get("instance_url"));
System.out.println("Id  :: "+token.get("id"));
System.out.println("Token_Type  :: "+token.get("token_type"));
System.out.println("Signature  :: "+token.get("signature"));
System.out.println("--------------------------------------------");

The token url would be the below.

final static String TOKEN_URL = "https://login.salesforce.com/services/oauth2/token";

Here is the output for reference:

--------------------------------------------
Access Token  :: 00D7F0000001I8v!ARgAQB7R8VtkU8QbUYHfdBjytHPATIDYmMKkPt7sunvUW4DeM2t.c.wFDJ0.k0uNPogX5aPWIrL_lHkrbfNai_t.byjjRCy_
Instance Url  :: https://ap5.salesforce.com
Id  :: https://login.salesforce.com/id/00D7F0000001I8vUAE/0057F000000l2bgQAA
Token_Type  :: Bearer
Signature  :: veYhITIlhqf9SJqvBAZ4PKiLh1sj9at13D3m44TnBxw=
--------------------------------------------

Answer 2

You are trying to send your query string parameters as headers (which is not the same). The following code will be equal to your test in Postman

public class RestTemplateExample {

    final static String TOKEN_URL = "https://ap5.salesforce.com/services/oauth2/token";

    public static void main(String[] args) {

    UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(TOKEN_URL)
        .queryParam("client_secret", "XXXXXXXXX")
        .queryParam("client_id", "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX")
        .queryParam("grant_type", "password")
        .queryParam("username", "[email protected]")
        .queryParam("password", "XXXXXXXXXXXX");

        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));

        HttpEntity<String> entity = new HttpEntity<String>("", headers);

        RestTemplate restTemplate = new RestTemplate();
        ResponseEntity<String> result = restTemplate.exchange(
            builder.build().encode().toUri(), 
            HttpMethod.POST, 
            entity, String.class
        );
        System.out.println("TOKEN DETAILS :: "+result.getBody());
    }
}