Java发送POST请求，参数为JSON格式，并接收返回JSON数据

原文地址：https://blog.csdn.net/qq_26975307/article/details/82713725

/**
     * 发送post请求
     * @param url  路径
     * @param jsonObject  参数(json类型)
     * @param encoding 编码格式
     * @return
     * @throws ParseException
     * @throws IOException
     */
    public static String send(String url, JSONObject jsonObject,String encoding) throws ParseException, IOException{
        String body = "";
 
        //创建httpclient对象
        CloseableHttpClient client = HttpClients.createDefault();
        //创建post方式请求对象
        HttpPost httpPost = new HttpPost(url);
 
        //装填参数
        StringEntity s = new StringEntity(jsonObject.toString(), "utf-8");
        s.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,
                "application/json"));
        //设置参数到请求对象中
        httpPost.setEntity(s);
        System.out.println("请求地址："+url);
//        System.out.println("请求参数："+nvps.toString());
 
        //设置header信息
        //指定报文头【Content-type】、【User-Agent】
//        httpPost.setHeader("Content-type", "application/x-www-form-urlencoded");
        httpPost.setHeader("Content-type", "application/json");
        httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
 
        //执行请求操作，并拿到结果（同步阻塞）
        CloseableHttpResponse response = client.execute(httpPost);
        //获取结果实体
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            //按指定编码转换结果实体为String类型
            body = EntityUtils.toString(entity, encoding);
        }
        EntityUtils.consume(entity);
        //释放链接
        response.close();
        return body;
    }