接口调用：从第三方接口获取数据

1.环境：系统框架：springboot，实现流程：controller→service

2.接口需求描述：

2. 代码示例

　2.1 .Controller层

@PostMapping("/vehicleSync")
@PassToken
public BaseResponse VehicleSync(){
    return carsyncService.VehicleSync();
}

　2.2 Service层

public BaseResponse VehicleSync() {
    //定义接口路径
    String apiUrl = "http://159.138.243.117:30000/app/get-vehilce-list/";
    //接口参数
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    String time = sdf.format(new Date());
    //定义一个JSONObject类型的rets用于接收返回的JSON数据
    Map<String, Object> postData = Maps.newHashMap();
    postData.put("updateTime", time);
    JSONObject rets = postData(apiUrl, JSONObject.toJSONString(postData));
    if (ObjectUtils.isEmpty(rets)) {
        return new BaseResponse(ResponseEnum.ERROR.getCode(), "Interface get parameter error");
    }
    //保存此条数据,框架是springboot，所以有Repository。不要生搬硬套代码
    String Code = (String) rets.get("code");
    if (ObjectUtils.isEmpty(Code)) {
        //调用成功
        JSONArray jsonArray = rets.getJSONArray("data");
        //用一个集合接收返回的json数据中的data的值，遍历集合，取出数据
        for (int i = 0, len = jsonArray.size(); i < len; i++) {
            JSONObject jsonObject2 = (JSONObject) jsonArray.get(i);
            VehicleSyncRequest request = new VehicleSyncRequest();
            request.setLicensePlate(jsonObject2.get("licensePlate").toString());
            request.setFuelType(jsonObject2.get("fuelType").toString());
            request.setDeviceNo(jsonObject2.get("deviceNo").toString());
            request.setSimNo(jsonObject2.get("simNo").toString());
            request.setUpdateTime(jsonObject2.get("updateTime").toString());
            request.setGuid(jsonObject2.get("guid").toString());
            if (!isexistVehicle(request)) {
                log.error("Failed to add new vehicle", request.getLicensePlate());
                continue;
            }
        }
    } else {
        return new BaseResponse(ResponseEnum.ERROR);
    }
    return new BaseResponse(ResponseEnum.SUCCESS);
}

public static JSONObject postData(String urls, String jsonObject) {
    try {
        /* 创建一个HttpClient最新版的实现类CloseableHttpClient */
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //接口参数
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String time = sdf.format(new Date());
        /* 创建post方法请求对象，并把拼接好的地址url赋值给它的请求参数urls */
        HttpPost httpPost = new HttpPost(urls);
        StringEntity stringEntity = new StringEntity(jsonObject, "UTF-8");
        httpPost.setEntity(stringEntity);
        httpPost.addHeader("X-Build-Number", "100");
        httpPost.addHeader("X-App-Version", "1.0.0");
        httpPost.addHeader("X-Device-System-Info", "HWC");
        httpPost.addHeader("X-Device-Type", "linux");
        httpPost.addHeader("X-Language-Code", "en");
        httpPost.addHeader("X-Time-Stamp", time);
        /* 设置报文头为Content-Type。具体格式看实际需求，我只知道如果请求的数据包为raw时，用Content-Type */
        httpPost.addHeader("Content-Type", "application/json");
        //执行请求操作，并拿到结果（同步阻塞）。（括号里的同步阻塞我也不知道什么意思，之后知道了再补上）
        /* 设置参数到请求对象中 */
        CloseableHttpResponse response = httpClient.execute(httpPost);
        log.info(response.toString());
        /* 获取结果实体 */
        HttpEntity entity = response.getEntity();
        /* 看返回状态是否正常，正常则把获取到的json字符串返回给调用者 */
        int statue = response.getStatusLine().getStatusCode();
        if (statue != HttpStatus.SC_OK) {
            log.error("http connect fail:{}", response.getStatusLine());
        }
        //返回结果
        String result = EntityUtils.toString(entity, "utf-8");
        log.info(result);
        return JSON.parseObject(result);
    } catch (Exception e) {
        log.error(e.toString());
        return JSON.parseObject(null);
    }
}

3. 设置header/body参数请求

3.1 创建header参数

HttpPost httpPost = new HttpPost(urls);
   httpPost.setEntity(stringEntity);
   httpPost.addHeader("X-Build-Number", "100");
   httpPost.addHeader("X-App-Version", "1.0.0");
   httpPost.addHeader("X-Device-System-Info", "HWC");       
   httpPost.addHeader("Content-Type", "application/json");        
   CloseableHttpResponse response = httpClient.execute(httpPost);

3.2 创建body参数

HttpPost httpPost = new HttpPost(urls);
httpPost.setHeader("Content-Type", "application/json");
JSONObject inner = new JSONObject();
inner.put("X-Build-Number", "100");
inner.put("X-App-Version", "1.0.0");
inner.put("X-Device-System-Info", "HWC");　
JSONObject param = new JSONObject();
param.put("HttpHeader", inner.toString());
httpPost.setEntity( new StringEntity(param.toString()));
CloseableHttpResponse response = httpClient.execute(httpPost);

4. 拉取依赖　

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.2</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.4</version>
</dependency>

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpcore</artifactId>
    <version>4.4.11</version>
</dependency>