RestTemplate 添加请求头headers和请求体body

        //headers
        HttpHeaders requestHeaders = new HttpHeaders();
        requestHeaders.add("api-version", "1.0");
        //body
        MultiValueMap<String, String> requestBody = new LinkedMultiValueMap<>();
        requestBody.add("roundid", "1");
        //HttpEntity
        HttpEntity<MultiValueMap> requestEntity = new HttpEntity<MultiValueMap>(requestBody, requestHeaders);
        RestTemplate restTemplate = new RestTemplate();
        //post
        ResponseEntity<String> responseEntity = restTemplate.postForEntity("http://xxx", requestEntity, String.class);
        System.out.println(responseEntity.getBody());