ahttpClient

public static void main(String[] args) throws IOException {
        //1.打开浏览器
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //2.声明get请求
        HttpGet httpGet = new HttpGet("http://www.baidu.com/");
        //3.发送请求
        CloseableHttpResponse response = httpClient.execute(httpGet);
        //4.判断状态码
        if(response.getStatusLine().getStatusCode()==200){
            HttpEntity entity = response.getEntity();
            //通过EntityUtils工具类转成字符串
            String string = EntityUtils.toString(entity, "utf-8");
            System.out.println(string);
        }
        //5.关闭资源
        response.close();
        httpClient.close();
    }

public String send(String postUrl,String json,String sign,String token) {
    String params = JSON.toJSONString(json);
    System.out.println(params);
    String url = postUrl;
    HttpClient httpClient = null;
    HttpPost postMethod = null;
    HttpResponse response = null;
    try {
        httpClient =  HttpClients.createDefault();
        postMethod = new HttpPost(url);//传入URL地址
        //设置请求头
        postMethod.addHeader("Content-type", "application/json");
        postMethod.addHeader("sign", sign);//设置请求头
        postMethod.addHeader("token",token);
        //传入请求参数
        postMethod.setEntity(new StringEntity(json, Charset.forName("UTF-8")));
        response = httpClient.execute(postMethod);//获取响应
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println("HTTP Status Code:" + statusCode);
        if (statusCode != HttpStatus.SC_OK) {
            System.out.println("HTTP请求未成功！HTTP Status Code:" + response.getStatusLine());
        }
        HttpEntity httpEntity = response.getEntity();
        String reponseContent = EntityUtils.toString(httpEntity);
        EntityUtils.consume(httpEntity);//释放资源
        System.out.println("响应内容：" + reponseContent);
        return reponseContent;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "";
}