// 发送GET请求
public static String sendGet(String orderCode, String requestUrl) throws Exception {
logger.info("requestUrl-start:" + requestUrl);
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;

    try {
        URIBuilder uriBuilder = new URIBuilder(requestUrl);
        uriBuilder.addParameter("orderNo", orderCode);
        HttpGet httpGet = new HttpGet(uriBuilder.build());
        httpGet.setHeader("Content-Type", MediaType.APPLICATION_JSON_UTF8.toString());
        response = httpClient.execute(httpGet);
        int errorCode = response.getStatusLine().getStatusCode();

        logger.info("sendOrderCenterPost-status:" + errorCode);
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            return EntityUtils.toString(entity, "utf-8");
        }
    } catch (Exception e) {
        logger.error("sendOrderCenterPost-exception" + orderCode, e);
    } finally {
        if (response != null) {
            response.close();
        }
        if (httpClient != null) {
            httpClient.close();
        }
    }
    return null;
}

// 发送POST请求
public static String resendPost(String reqJsonData, String requestUrl) throws Exception {
logger.info("requestUrl-start:" + requestUrl);
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;

    try {
                    HttpPost httpPost = new HttpPost(requestUrl);
                    httpPost.setHeader("Content-Type", MediaType.APPLICATION_JSON_UTF8.toString());
                    httpPost.setEntity(new StringEntity(reqJsonData, "UTF-8"));
        response = httpClient.execute(httpPost);
        int errorCode = response.getStatusLine().getStatusCode();

        logger.info("发送请求的响应状态:" + errorCode);
                    HttpEntity entity = response.getEntity();
        if (entity != null) {
            return EntityUtils.toString(entity, "utf-8");
        }
    } catch (Exception e) {
        logger.error("重推日志系统异常", e);
    } finally {
        if (response != null) {
            response.close();
        }
        if (httpClient != null) {
            httpClient.close();
        }
    }
    return null;
}

    说明: 一般常用的响应格式是定义一个JSON对象，所以，对GET/POST请求返回的字符串可以用   JSON.parseObject(resStr, ReturnObject.class); 进行解析