http带请求头，请求体的接口调用
用到的包：org.springframework.http
MultiValueMap<String, String> multiValueMap = new LinkedMultiValueMap<>();
MultiValueMap<String, String> requestBody=multiValueMap;
requestBody.add("param1",param1);
requestBody.add("param2",param2);
requestBody.add("param3",param3);
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("Accept-Charset", "utf-8");
requestHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<>(requestBody, requestHeaders);
自己写一个ReponseBody类用来接收响应的参数
使用spring中现有的包 。 org.springframework.web.client.RestTemplate
ReponseBody body=restTemplate.exchange(url, HttpMethod.POST, entity,
ReponseBody.class).getBody();
就能获取响应的响应体
