使用HttpClient发送和接收JSON请求

/**
     * post请求
     * @param url
     * @param json
     * @return
     */
    public static JSONObject doPost(String url,JSONObject json){
        
        CloseableHttpClient httpclient = HttpClientBuilder.create().build();
        HttpPost post = new HttpPost(url);
        JSONObject response = null;
        try {
            StringEntity s = new StringEntity(json.toString());
            s.setContentEncoding("UTF-8");
            s.setContentType("application/json");//发送json数据需要设置contentType
            post.setEntity(s);
            HttpResponse res = httpclient.execute(post);
            if(res.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
                String result = EntityUtils.toString(res.getEntity());// 返回json格式：
                response = JSONObject.fromObject(result);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return response;
    }

 maven依赖包：

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