引入pom依赖

   <!--  RestTemplate  -->

<dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
       <version>4.5.10</version>
 </dependency>

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.60</version>
</dependency>

postForObject方法

@Resource
private RestTemplate restTemplate;
 
 
//方法中代码
String url = ltUrlProperties.getCalculateUrl();
            log.info("返回测算信息url======={}",url);
            Map<String, Object> errReturn =  new HashMap<>();
            errReturn.put("code","500");
            errReturn.put("message","测算失败");
            errReturn.put("versionNo",versionCodeAndUcode.getVersionCode());
            errReturn.put("uniqueId",versionCodeAndUcode.getUniqueId());
            JSONObject jsonObject = JSONUtil.parseObj(errReturn);
            String jsonStringErr  = JSONUtil.toJsonStr(jsonObject);
//   String jsonStringErr = JSON.toJSONString(ImmutableMap.of("userId", userId), SerializerFeature.WriteMapNullValue);
            log.info("发送给龙头的测算返回信息=========={}",jsonStringErr);
            HttpHeaders headersErr = new HttpHeaders();
            headersErr.setContentType(MediaType.APPLICATION_JSON_UTF8);
            headersErr.add("token", "我是token");
            HttpEntity<String> httpEntityErr = new HttpEntity<>(jsonStringErr, headersErr);
            String responseErr = this.restTemplate.postForObject(url, httpEntityErr, String.class);
            log.info("龙头接收返回信息=========={}",responseErr);

getForObject方法

@Resource
private RestTemplate restTemplate;
 
String url = appConfig.getC1tm().getPushToC2()+"f_code="+c1InterfaceApi.getProjectCode()+"&version="+c1InterfaceApi.getVersion();
JSONObject result = this.restTemplate.getForObject(url,JSONObject.class);
log.info("返回数据：{}",result.toString());

exchange方法之post

Map<String, Object> requestMap = ImmutableMap.of("Parameters", parameters);
        String jsonString = JSONObject.toJSONString(requestMap);
 
        String requestURL = url;
        log.info("=======调用接口: {}", requestURL);
 
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.add("Authorization", "Basic " + encodeBase64String(username, password));
 
        HttpEntity<String> httpEntity = new HttpEntity<>(jsonString, headers);
        ResponseEntity<String> responseEntity = this.restTemplate.exchange(requestURL, HttpMethod.POST, httpEntity, String.class);
        log.info("=======调用接口response: {}", responseEntity);

exchange方法之get

 StringBuilder strBu = new StringBuilder();
                strBu.append("?versionCode=").append(versionCode);
                strBu.append("&projectCode=").append(projectCode);
                String parseC3ExcelUrl = url;
                parseC3ExcelUrl = parseC3ExcelUrl + strBu.toString();
                String apiKey = this.config.getZncsConfig().getGaiaApiKey();
                HttpHeaders httpHeaders = new HttpHeaders();
                httpHeaders.add("X-Gaia-Api-Key",apiKey);
                HttpEntity<String> entity = new HttpEntity<>("parameters",httpHeaders);
                log.info("接口调用："+parseC3ExcelUrl+"===="+apiKey);
                ResponseEntity<String> responseEntity = restTemplate.exchange(parseC3ExcelUrl, HttpMethod.GET,entity,String.class);
  log.info("接口响应："+responseEntity.getStatusCode() + responseEntity.getBody());

x-www-form-urlencoded格式请求

String url = this.appConfig.getNcConfig().getTokenUrl();
        String clientId = this.appConfig.getNcConfig().getClientId();
        String clientSecret = this.appConfig.getNcConfig().getClientSecret();
        String token = null;
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
        MultiValueMap<String, String> param = new LinkedMultiValueMap<>(3);
        param.add("client_id", clientId);
        param.add("client_secret", clientSecret);
        param.add("grant_type", "client_credentials");
        HttpEntity<MultiValueMap<String, String>> httpEntity = new HttpEntity<>(param, headers);
        String result = restTemplate.postForObject(url, httpEntity, String.class);
        if (StringUtils.isNotBlank(result)) {
            JSONObject jsonResult = JSONObject.parseObject(result);