android - 无法写入请求: no suitable HttpMessageConverter found for request type [org. json.JSONObject]和内容类型[application/json]

我正在努力尝试将带有JSON有效负载的POST请求发送到远程服务器。

此GET curl命令可以正常工作:

curl -H "Accept:application/json" --user aaa@aaa.com:aaa "http://www.aaa.com:8080/aaa-project-rest/api/users/1" -i

而且这个POST也可以正常工作:

curl -H "Accept:application/json" -H "Content-Type: application/json" "http://www.aaa.com:8080/aaa-project-rest/api/users/login" -X POST -d "{ \"email\" : \"aaa@aaa.com\", \"password\" : \"aaa\" }" -i

因此，我试图在我的Android应用程序中模仿它。

该应用程序在第一个GET请求上运行良好，但在第二个POST请求上给出了400错误请求。

以下是适用于GET请求的代码:

  RestTemplate restTemplate = new RestTemplate();
  restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
  HttpHeaders httpHeaders = Common.createAuthenticationHeaders("aaa@aaa.com" + ":" + "aaa");
  User user = null;
  ResponseEntity<User> responseEntity = restTemplate.exchange("http://" + REST_HOST + ":8080/aaa-project-rest/api/users/" + 1L, HttpMethod.GET, new HttpEntity<Object>(httpHeaders), User.class);

这是POST请求的源代码:

RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
User user = null;
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
httpHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
JSONObject jsonCredentials = new JSONObject();
jsonCredentials.put("email", REST_LOGIN);
jsonCredentials.put("password", REST_PASSWORD);
ResponseEntity<User> responseEntity = restTemplate.exchange("http://" + REST_HOST + ":" + REST_PORT + "/" + REST_APP + "/api/users/login",
        HttpMethod.POST, new HttpEntity<Object>(jsonCredentials, httpHeaders), User.class);

但是它给出了以下信息:

Could not write request: no suitable HttpMessageConverter found for request type [org.json.JSONObject] and content type [application/json]

这是Spring REST Controller :

@RequestMapping(value = RESTConstants.SLASH + RESTConstants.LOGIN, method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public ResponseEntity<UserResource> login(@Valid @RequestBody CredentialsResource credentialsResource, UriComponentsBuilder builder) {
    HttpHeaders responseHeaders = new HttpHeaders();
    User user = credentialsService.checkPassword(credentialsResource);
    userService.clearReadablePassword(user);
    if (user == null) {
        return new ResponseEntity<UserResource>(responseHeaders, HttpStatus.NOT_FOUND);
    } else {
        tokenAuthenticationService.addTokenToResponseHeader(responseHeaders, credentialsResource.getEmail());
        responseHeaders.setLocation(builder.path(RESTConstants.SLASH + RESTConstants.USERS + RESTConstants.SLASH + "{id}").buildAndExpand(user.getId()).toUri());
        UserResource createdUserResource = userResourceAssembler.toResource(user);
        ResponseEntity<UserResource> responseEntity = new ResponseEntity<UserResource>(createdUserResource, responseHeaders, HttpStatus.CREATED);
        return responseEntity;
    }
}

@RequestMapping(value = RESTConstants.SLASH + "{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public ResponseEntity<UserResource> findById(@PathVariable Long id, UriComponentsBuilder builder) {
    HttpHeaders responseHeaders = new HttpHeaders();
    User user = userService.findById(id);
    if (user == null) {
        return new ResponseEntity<UserResource>(responseHeaders, HttpStatus.NOT_FOUND);
    } else {
        UserResource userResource = userResourceAssembler.toResource(user);
        responseHeaders.setLocation(builder.path(RESTConstants.SLASH + RESTConstants.USERS + RESTConstants.SLASH + "{id}").buildAndExpand(user.getId()).toUri());
        ResponseEntity<UserResource> responseEntity = new ResponseEntity<UserResource>(userResource, responseHeaders, HttpStatus.OK);
        return responseEntity;
    }
}

CredentialsResource类代码:

public class CredentialsResource extends ResourceSupport {

    @NotEmpty
    @Email
    private String email;
    @NotEmpty
    private String password;

    public CredentialsResource() {
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

最佳答案

尽管我刚刚遇到了同样的问题，花了一些时间来解决，但回复时间还很晚。因此，我认为最好共享它并跟踪我的解决方案。

实际上，抛出的异常完全是误导性的。原来的问题不是MappingJackson2HttpMessageConverter不知道如何编码对象(听起来很奇怪，是JSON)，而是底层ObjectMapper的配置。

我所做的是像这样禁用属性SerializationFeature.FAIL_ON_EMPTY_BEANS

restTemplate = new RestTemplate();
MappingJackson2HttpMessageConverter jsonHttpMessageConverter = new MappingJackson2HttpMessageConverter();
jsonHttpMessageConverter.getObjectMapper().configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
restTemplate.getMessageConverters().add(jsonHttpMessageConverter);

一切开始按预期进行。

关于android - 无法写入请求: no suitable HttpMessageConverter found for request type [org. json.JSONObject]和内容类型[application/json]，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/28753773/