restTemplate post使用

 private String generateScheme(GetWechatSchemeReq req, String accessToken) {
        String path = req.getPath();
        String query = req.getQuery();
        String url = "http://www.abc.com?abc=111";
        WechatSchemeRequest wechatSchemeRequest = new WechatSchemeRequest(path, query, expireType, expireInterval);
        ResponseEntity<byte[]> responseEntity;
        try {
            responseEntity = restTemplate.exchange(
                    url,
                    HttpMethod.POST,
                    createEntity(wechatSchemeRequest),
                    new ParameterizedTypeReference<byte[]>() {
                    }
            );
            byte[] resultByte = responseEntity.getBody();
            String resultStr = new String(resultByte, StandardCharsets.UTF_8);
            if (log.isDebugEnabled()) {
                log.debug("generateScheme url={},response={}", url, resultStr);
            }
            ObjectMapper object_mapper = new ObjectMapper();
            JsonNode jsonNode = object_mapper.readValue(resultStr, JsonNode.class);

            JsonNode openlink = jsonNode.get("openlink");
            if (openlink!=null) {
                return openlink.asText();
            }
            log.error("generateScheme error url={},response={}", url, resultStr);
            throw new RuntimeException("获取scheme异常,error:" + resultStr);

        } catch (JsonMappingException e) {
            log.error("generateScheme error:{}", e);
            throw new RuntimeException(e);
        } catch (JsonProcessingException e) {
            log.error("generateScheme error:{}", e);
            throw new RuntimeException(e);
        }
    }

    private static <Object> HttpEntity<String> createEntity(Object body) {
        HttpHeaders headers = new HttpHeaders();
        MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
        headers.setContentType(type);
        headers.add("Accept", MediaType.APPLICATION_JSON.toString());
        String bodyJson = "";
        if (body != null) {
            bodyJson = JsonUtil.toJSONString(body);
        }
        return new HttpEntity<>(bodyJson, headers);
    }