如何在 Spring RestTemplate 请求上设置“接受：”标头？

How to set an "Accept:" header on Spring RestTemplate request?

提问by edaklij

I want to set the value of the Accept:in a request I am making using Spring's RestTemplate.

我想Accept:在我使用 Spring 的RestTemplate.

Here is my Spring request handling code

这是我的 Spring 请求处理代码

@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:

这是我的 Java REST 客户端：

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.

这对我有用；我从服务器端得到一个 JSON 字符串。

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?

我的问题是：当我使用 RestTemplate 时，如何指定Accept:标头（例如application/json, application/xml, ... ）和请求方法（例如GET, POST, ... ）？

回答by Sotirios Delimanolis

I suggest using one of the exchangemethods that accepts an HttpEntityfor which you can also set the HttpHeaders. (You can also specify the HTTP method you want to use.)

我建议使用exchange接受 a的方法之一HttpEntity，您还可以为其设置HttpHeaders. （您还可以指定要使用的 HTTP 方法。）

For example,

例如，

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. exchangeexpects an HttpEntity.

我更喜欢这个解决方案，因为它是强类型的，即。exchange期待一个HttpEntity.

However, you can also pass that HttpEntityas a requestargument to postForObject.

但是，您也可以将其HttpEntity作为request参数传递给postForObject.

HttpEntity<String> entity = new HttpEntity<>("body", headers);
restTemplate.postForObject(url, entity, String.class); 

This is mentioned in the RestTemplate#postForObjectJavadoc.

这是在RestTemplate#postForObjectJavadoc 中提到的。

The requestparameter can be a HttpEntityin order to add additional HTTP headers to the request.

该request参数可以是HttpEntity在为了增加额外的HTTP标头的请求。

回答by Ammar

You could set an interceptor "ClientHttpRequestInterceptor" in your RestTemplate to avoid setting the header every time you send a request.

您可以在 RestTemplate 中设置拦截器“ClientHttpRequestInterceptor”，以避免每次发送请求时都设置标头。

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

然后

List<ClientHttpRequestInterceptor> interceptors = new ArrayList<ClientHttpRequestInterceptor>();
interceptors.add(new HeaderRequestInterceptor("Accept", MediaType.APPLICATION_JSON_VALUE));

RestTemplate restTemplate = new RestTemplate();
restTemplate.setInterceptors(interceptors);

回答by Dave

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...

如果像我一样，您很难找到一个使用带有基本身份验证的标头和其余模板交换 API 的示例，这就是我最终确定的...

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());
    }
}

回答by vaquar khan

Calling a RESTful API using RestTemplate

使用 RestTemplate 调用 RESTful API

Example 1:

示例 1：

RestTemplate restTemplate = new RestTemplate();
// Add the Hymanson message converter
restTemplate.getMessageConverters()
                .add(new MappingHymanson2HttpMessageConverter());
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:

示例 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 getRequestJsonmethod creates a JSON Object:

该getRequestJson方法创建一个 JSON 对象：

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;
}

回答by Tunde Michael

Here is a simple answer. Hope it helps someone.

这是一个简单的答案。希望它可以帮助某人。

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;
}