no suitable HttpMessageConverter found for response type and content type

Question

I was trying to get the ResponseEntity with spring rest template as given below. I am getting the below error,

Caused by: org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [interface org.springframework.security.oauth2.common.OAuth2AccessToken] and content type [application/json;charset=ISO-8859-1]

Code:

ResourceOwnerPasswordResourceDetails resource = new ResourceOwnerPasswordResourceDetails();

        resource.setAccessTokenUri("https://.../oauth2/token");
        resource.setUsername("u");
        resource.setPassword("p");
        resource.setClientSecret(".....s");
        resource.setClientId("....i");
        resource.setGrantType("password");
        List<String> scopes = new ArrayList<String>(2);
        scopes.add("write");
        scopes.add("read");
        resource.setScope(scopes);
         OAuth2RestTemplate oAuthRestTemplate =  new OAuth2RestTemplate(resource);

    try{
        SSLUtil.turnOffSslChecking();
        ResponseEntity<String> result = oAuthRestTemplate.getForEntity("https:......." + "/api/version", String.class);
        System.out.println(result);
          } catch (RestClientException e) {         
            e.printStackTrace();
        }

I tried setting Media type as Application/json as in this post.But still the same error.

Full trace:

Exception in thread "main" error="access_denied", error_description="Error requesting access token."
    at org.springframework.security.oauth2.client.token.OAuth2AccessTokenSupport.retrieveToken(OAuth2AccessTokenSupport.java:121)
    at org.springframework.security.oauth2.client.token.grant.password.ResourceOwnerPasswordAccessTokenProvider.obtainAccessToken(ResourceOwnerPasswordAccessTokenProvider.java:47)
    at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainNewAccessTokenInternal(AccessTokenProviderChain.java:142)
    at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainAccessToken(AccessTokenProviderChain.java:118)
    at org.springframework.security.oauth2.client.OAuth2RestTemplate.acquireAccessToken(OAuth2RestTemplate.java:216)
    at org.springframework.security.oauth2.client.OAuth2RestTemplate.getAccessToken(OAuth2RestTemplate.java:168)
    at org.springframework.security.oauth2.client.OAuth2RestTemplate.createRequest(OAuth2RestTemplate.java:89)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:479)
    at org.springframework.security.oauth2.client.OAuth2RestTemplate.doExecute(OAuth2RestTemplate.java:123)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:446)
    at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:236)
    at com.ClientTemplate.main(ClientTemplate.java:56)
Caused by: org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [interface org.springframework.security.oauth2.common.OAuth2AccessToken] and content type [application/json;charset=ISO-8859-1]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:107)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:491)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:454)
    at org.springframework.security.oauth2.client.token.OAuth2AccessTokenSupport.retrieveToken(OAuth2AccessTokenSupport.java:113)
    ... 11 more

Answer 1

You need to add MappingJackson2HttpMessageConverter and add content type to be application/json to the header. See here