我必须进行REST调用,其中包括自定义头和查询参数。我设置我的HttpEntity只有头(没有正文),我使用RestTemplate.exchange()方法如下:
HttpHeaders headers = new HttpHeaders();
headers.set("Accept", "application/json");
Map<String, String> params = new HashMap<String, String>();
params.put("msisdn", msisdn);
params.put("email", email);
params.put("clientVersion", clientVersion);
params.put("clientType", clientType);
params.put("issuerName", issuerName);
params.put("applicationName", applicationName);
HttpEntity entity = new HttpEntity(headers);
HttpEntity<String> response = restTemplate.exchange(url, HttpMethod.GET, entity, String.class, params);
这在客户端失败,因为调度程序servlet无法将请求解析到处理程序。调试之后,似乎没有发送请求参数。
当我使用请求体和没有查询参数的POST做一个交换时,它工作得很好。
有人有什么想法吗?
为了方便地操作URL / path / params /等等,您可以使用Spring的UriComponentsBuilder类创建一个URL模板,其中包含参数占位符,然后在RestOperations.exchange(…)调用中提供这些参数的值。它比手动连接字符串更干净,它会为你处理URL编码:
HttpHeaders headers = new HttpHeaders();
headers.set(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON_VALUE);
HttpEntity<?> entity = new HttpEntity<>(headers);
String urlTemplate = UriComponentsBuilder.fromHttpUrl(url)
.queryParam("msisdn", "{msisdn}")
.queryParam("email", "{email}")
.queryParam("clientVersion", "{clientVersion}")
.queryParam("clientType", "{clientType}")
.queryParam("issuerName", "{issuerName}")
.queryParam("applicationName", "{applicationName}")
.encode()
.toUriString();
Map<String, ?> params = new HashMap<>();
params.put("msisdn", msisdn);
params.put("email", email);
params.put("clientVersion", clientVersion);
params.put("clientType", clientType);
params.put("issuerName", issuerName);
params.put("applicationName", applicationName);
HttpEntity<String> response = restOperations.exchange(
urlTemplate,
HttpMethod.GET,
entity,
String.class,
params
);
如果您为RestTemplate传递非参数参数,那么考虑到参数,您将为传递的每个不同URL都有一个Metrics。你想要使用参数化url:
http://my-url/action?param1={param1}¶m2={param2}
而不是
http://my-url/action?param1=XXXX¶m2=YYYY
第二种情况是使用UriComponentsBuilder类得到的结果。
实现第一个行为的方法如下:
Map<String, Object> params = new HashMap<>();
params.put("param1", "XXXX");
params.put("param2", "YYYY");
String url = "http://my-url/action?%s";
String parametrizedArgs = params.keySet().stream().map(k ->
String.format("%s={%s}", k, k)
).collect(Collectors.joining("&"));
HttpHeaders headers = new HttpHeaders();
headers.set("Accept", MediaType.APPLICATION_JSON_VALUE);
HttpEntity<String> entity = new HttpEntity<>(headers);
restTemplate.exchange(String.format(url, parametrizedArgs), HttpMethod.GET, entity, String.class, params);
我提供了一个RestTemplate GET方法的代码片段与路径参数示例
public ResponseEntity<String> getName(int id) {
final String url = "http://localhost:8080/springrestexample/employee/name?id={id}";
Map<String, String> params = new HashMap<String, String>();
params.put("id", id);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity request = new HttpEntity(headers);
ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.GET, String.class, params);
return response;
}