I want to set the value of the Accept:
in a request I am making using Spring's RestTemplate
.
Here is my Spring request handling code
@RequestMapping(
value= "/uom_matrix_save_or_edit",
method = RequestMethod.POST,
produces="application/json"
)
public @ResponseBody ModelMap uomMatrixSaveOrEdit(
ModelMap model,
@RequestParam("parentId") String parentId
){
model.addAttribute("attributeValues",parentId);
return model;
}
and here is my Java REST client:
public void post(){
MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
params.add("parentId", "parentId");
String result = rest.postForObject( url, params, String.class) ;
System.out.println(result);
}
This works for me; I get a JSON string from the server side.
My question is: how can I specify the Accept:
header (e.g. application/json
,application/xml
, ... ) and request method (e.g. GET
,POST
, ... ) when I use RestTemplate?
This question is related to
spring
rest
resttemplate
I suggest using one of the exchange
methods that accepts an HttpEntity
for which you can also set the HttpHeaders
. (You can also specify the HTTP method you want to use.)
For example,
RestTemplate restTemplate = new RestTemplate();
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<>("body", headers);
restTemplate.exchange(url, HttpMethod.POST, entity, String.class);
I prefer this solution because it's strongly typed, ie. exchange
expects an HttpEntity
.
However, you can also pass that HttpEntity
as a request
argument to postForObject
.
HttpEntity<String> entity = new HttpEntity<>("body", headers);
restTemplate.postForObject(url, entity, String.class);
This is mentioned in the RestTemplate#postForObject
Javadoc.
The
request
parameter can be aHttpEntity
in order to add additional HTTP headers to the request.
You could set an interceptor "ClientHttpRequestInterceptor" in your RestTemplate to avoid setting the header every time you send a request.
public class HeaderRequestInterceptor implements ClientHttpRequestInterceptor {
private final String headerName;
private final String headerValue;
public HeaderRequestInterceptor(String headerName, String headerValue) {
this.headerName = headerName;
this.headerValue = headerValue;
}
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
request.getHeaders().set(headerName, headerValue);
return execution.execute(request, body);
}
}
Then
List<ClientHttpRequestInterceptor> interceptors = new ArrayList<ClientHttpRequestInterceptor>();
interceptors.add(new HeaderRequestInterceptor("Accept", MediaType.APPLICATION_JSON_VALUE));
RestTemplate restTemplate = new RestTemplate();
restTemplate.setInterceptors(interceptors);
Here is a simple answer. Hope it helps someone.
import org.springframework.boot.devtools.remote.client.HttpHeaderInterceptor;
import org.springframework.http.MediaType;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.web.client.RestTemplate;
public String post(SomeRequest someRequest) {
// create a list the headers
List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
interceptors.add(new HttpHeaderInterceptor("Accept", MediaType.APPLICATION_JSON_VALUE));
interceptors.add(new HttpHeaderInterceptor("ContentType", MediaType.APPLICATION_JSON_VALUE));
interceptors.add(new HttpHeaderInterceptor("username", "user123"));
interceptors.add(new HttpHeaderInterceptor("customHeader1", "c1"));
interceptors.add(new HttpHeaderInterceptor("customHeader2", "c2"));
// initialize RestTemplate
RestTemplate restTemplate = new RestTemplate();
// set header interceptors here
restTemplate.setInterceptors(interceptors);
// post the request. The response should be JSON string
String response = restTemplate.postForObject(Url, someRequest, String.class);
return response;
}
If, like me, you struggled to find an example that uses headers with basic authentication and the rest template exchange API, this is what I finally worked out...
private HttpHeaders createHttpHeaders(String user, String password)
{
String notEncoded = user + ":" + password;
String encodedAuth = Base64.getEncoder().encodeToString(notEncoded.getBytes());
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
headers.add("Authorization", "Basic " + encodedAuth);
return headers;
}
private void doYourThing()
{
String theUrl = "http://blah.blah.com:8080/rest/api/blah";
RestTemplate restTemplate = new RestTemplate();
try {
HttpHeaders headers = createHttpHeaders("fred","1234");
HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);
ResponseEntity<String> response = restTemplate.exchange(theUrl, HttpMethod.GET, entity, String.class);
System.out.println("Result - status ("+ response.getStatusCode() + ") has body: " + response.hasBody());
}
catch (Exception eek) {
System.out.println("** Exception: "+ eek.getMessage());
}
}
Example 1:
RestTemplate restTemplate = new RestTemplate();
// Add the Jackson message converter
restTemplate.getMessageConverters()
.add(new MappingJackson2HttpMessageConverter());
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
headers.set("Authorization", "Basic XXXXXXXXXXXXXXXX=");
HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);
restTemplate.getInterceptors()
.add(new BasicAuthorizationInterceptor(USERID, PWORD));
String requestJson = getRequetJson(Code, emailAddr, firstName, lastName);
response = restTemplate.postForObject(URL, requestJson, MYObject.class);
Example 2:
RestTemplate restTemplate = new RestTemplate();
String requestJson = getRequetJson(code, emil, name, lastName);
HttpHeaders headers = new HttpHeaders();
String userPass = USERID + ":" + PWORD;
String authHeader =
"Basic " + Base64.getEncoder().encodeToString(userPass.getBytes());
headers.set(HttpHeaders.AUTHORIZATION, authHeader);
headers.setContentType(MediaType.APPLICATION_JSON);
headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
HttpEntity<String> request = new HttpEntity<String>(requestJson, headers);
ResponseEntity<MyObject> responseEntity;
responseEntity =
this.restTemplate.exchange(URI, HttpMethod.POST, request, Object.class);
responseEntity.getBody()
The getRequestJson
method creates a JSON Object:
private String getRequetJson(String Code, String emailAddr, String name) {
ObjectMapper mapper = new ObjectMapper();
JsonNode rootNode = mapper.createObjectNode();
((ObjectNode) rootNode).put("code", Code);
((ObjectNode) rootNode).put("email", emailAdd);
((ObjectNode) rootNode).put("firstName", name);
String jsonString = null;
try {
jsonString = mapper.writerWithDefaultPrettyPrinter()
.writeValueAsString(rootNode);
}
catch (JsonProcessingException e) {
e.printStackTrace();
}
return jsonString;
}
Source: Stackoverflow.com