如何在 Spring 中使用 RestTemplate 获取数据

Question

我的任务是编写代码以通过 URL 从剩余 API 获取数据，就像这样

curl -k -v -XPOST -H "username: password" -H "Content-type: application/json" http://localhost:8181/api/rest/person/query -d '
    {
        "name": "person's name",
        "role": "role code",
        "programme": "programme code"
    }'

这是我的代码

   public JsonUser fetchJsonUserByName(String name) throws IOException{
       String jsonName = "'{'name': "+"'"+name+"'}'";
       String url = "/person/query -d "+jsonName;
       ResponseEntity<JsonUser> response = restTemplate.getForEntity(url, JsonUser.class);
           try {
            if(response.hasBody()) return response.getBody();
               else return null;
        } catch (HttpStatusCodeException e) {
            if(e.getStatusCode() == HttpStatus.NOT_FOUND) return null;
            throw new IOException("error fetching user", e);
        } catch (Exception e) {
            throw new IOException("error fetching user", e);
        }
   }

当我运行我的代码时，我得到了错误代码 500，我哪里错了？

Answer 1

首先，这个问题中没有关于 Spring Integration 的内容。以后请注意标签选择。

你在这里的错误是你错过了你使用 POST HTTP 方法和 curl 的部分。但是对于 RestRemplate 你选择 GET:

/**
 * Retrieve an entity by doing a GET on the specified URL.
 * The response is converted and stored in an {@link ResponseEntity}.
 * <p>URI Template variables are expanded using the given URI variables, if any.
 * @param url the URL
 * @param responseType the type of the return value
 * @param uriVariables the variables to expand the template
 * @return the entity
 * @since 3.0.2
 */
<T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object... uriVariables) throws RestClientException;

我猜你是这个意思：

/**
 * Create a new resource by POSTing the given object to the URI template,
 * and returns the response as {@link ResponseEntity}.
 * <p>URI Template variables are expanded using the given URI variables, if any.
 * <p>The {@code request} parameter can be a {@link HttpEntity} in order to
 * add additional HTTP headers to the request.
 * @param url the URL
 * @param request the Object to be POSTed (may be {@code null})
 * @param uriVariables the variables to expand the template
 * @return the converted object
 * @since 3.0.2
 * @see HttpEntity
 */
<T> ResponseEntity<T> postForEntity(String url, Object request, Class<T> responseType, Object... uriVariables)
        throws RestClientException;

Answer 2

请商议HTTP response codes, explained，你会看到500是“我操蛋”的意思，这是服务器的观点。这是服务器错误，不是你的。

当然，服务器错误可能是由于输入格式错误造成的，例如您发送的完全错误URL /person/query -d '{'name': 'name'}'.

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